bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of mu‐opioid receptors in commissural nucleus tractus solitarius markedly depresses hypoxic, but not hypercapnic, ventilatory response in conscious rats (712.11)
Authors: Zhuang Jianguo , Lin Amy , Xu Fadi
Published: June 2021

Activation of cNTS MORs blocks HVR and moderately depresses HCVR (↓30%) in anesthetized rats (Zhang et al, Anesthesiology 2011) in agreement with the cNTS synaptically receiving carotid body afferents and heavily expressing MORs. Because of synergistic effect of anesthesia on opioids’ impacts and projections of bronchopulmonary C‐fibers (PCFs) to the cNTS, we asked whether stimulation of cNTS MORs would alter HVR, HCVR, and PCF‐mediated apnea in conscious state. cNTS catheter guide was instrumented in the anesthetized rats with the right site ensured by lack of HVR following local injection of DAMGO (2.5 mM, 30 nl), a MOR agonist. After recovery from surgery, three groups of conscious animals were individually placed in a whole‐body plethysmograph to: inhale 10% O2 for 2 min or 7% CO2 for 5 min, or receive right atrial bolus injection of capsaicin (CAP, 1 μg/kg) before and 5 min after intra‐cNTS microinjection of DAMGO with and without previous local blockade of MORs by CTAP (10 mM, 30 nl). Microinjection of DAMGO into the cNTS decreased baseline VE (↓16%) mainly via lowering fR and reduced HVR and PCF‐mediated apnea (63% and 20%, P < 0.01) without effect on HCVR. Microinjection of DAMGO following CTAP failed to alter HVR. Our data suggest that cNTS MORs play a critical role in depressing respiratory chemoreflexes in conscious state and this influence is largely strengthened by anesthesia.

Grant Funding Source: Supported by HL‐107462
Increased Ca2+ permeable ampa receptor expression following carotid body denervation in goats (713.2)
Authors: Miller Justin , Neumueller S , Muere C , Olesiak S , Daghistany A , Pan L , Hodges M , Forster H
Published: June 2021

The mechanisms which contribute to the time‐dependent recovery of resting ventilation and the ventilatory CO2 chemoreflex after carotid body denervation (CBD) are poorly understood. The initiation of neuronal plasticity often involves changes in Ca2+ permeability. Therefore, we tested the hypothesis that during recovery from the acute effects of CBD in goats, there is an increase in Ca2+ permeable GluA1R and GluN1R and/or a decrease in Ca2+ impermeable GluA2R expression at brainstem sites that contribute to respiratory control. We tested this hypothesis via optical densitometric (OD) quantification of medullary neurons immunostained with antibodies targeting GluA1R, GluA2R, and GluN1R at 5‐13 days or 30 days after bilateral CBD. CBD resulted in hypoventilation and a reduced CO2 chemoreflex, which both recovered significantly over 30 days post‐CBD. At 5‐13 days post‐CBD, GluA1 OD was unchanged from control goats, but GluA2 and GluN1 OD were reduced 15‐30% within 6 of medullary respiratory nuclei measured. However, at 30 days post‐CBD GluA1 OD remained unchanged, but GluA2 and GluN1 OD returned to control levels. We conclude that a shift toward Ca2+ permeable glutamate receptors 5‐13 days post‐CBD may initiate the recovery of ventilation after CBD. Furthermore, at 30 days post‐CBD the partial recovery of ventilation is maintained by relatively normal glutamate receptor expression.

Grant Funding Source: Supported by National Heart, Lung, and Blood Institute Grants HL25739 and HL007852 and by VA
Prenatal nicotinic exposure increases pulmonary C neural response to capsaicin associated with upregulation of TRPV1 in nodose ganglia neurons (713.4)
Authors: Zhuang Jianguo , Zhao Lei , Zang Na , Xu Fadi
Published: June 2021

We have reported that stimulation of pulmonary C‐fibers (PCFs) during hypoxia produces a long‐lasting apnea or lethal ventilatory arrest in rats and that PNE promotes apneic and lethal ventilatory arrest responses to hypoxia (5% O2 for 60 min) in rat pups. Here, we tested whether PNE‐induced apneic and lethal ventilatory arrest were of central origin without airway hyperreactivity (AHR). We further tested whether PNE enhanced pulmonary C neural response to capsaicin (CAP) associated with upregulation of TRPV1 in nodose ganglion neurons. In Ctrl and PNE‐treated pups, we recorded: i) diaphragm EMG during 5% O2 up to 60 min and ii) specific airway resistance (sRaw) response to increasing dose of aerosol methacholine (0, 3.125, 6.25, 12.5, 25 mg/ml) in conscious state; iii) pulmonary C neural response to right atrial bolus injection of CAP (1 μg/kg) in anesthetized and paralyzed state; and iv) TRPV1 mRNA expression in neurons of nodose ganglia (by RT‐PCR). PNE produced apnea and lethal ventilatory arrest concomitant with silence of diaphragm EMG and did not induce AHR. PNE increased pulmonary C neural firing response to CAP associated with upregulation of TRPV1 in nodose ganglia neurons. We conclude that PNE increases PCF sensitivity likely through increasing TRPV1 expression, contributing to the PNE‐promoted central origin of the apneic and lethal ventilatory arrest responses to hypoxia.

Grant Funding Source: Supported by HL‐107462
RNA sequencing to profile transcriptional changes within the medullary raphe: potential mechanisms of central neuroplasticity driving the recovery of eupneic ventilation after bilateral carotid body denervation (713.7)
Authors: Mouradian Gary , Forster Hubert , Hodges Matthew
Published: June 2021

Bilateral carotid body denervation (CBD) in rats elicits eupneic (resting) hypoventilation 1‐2 d post‐CBD, which relatively rapidly returns to baseline values (14‐15 d). We have previously shown increases in brainstem serotonin (5‐HT) turnover and the 5‐HT transporter (SERT) acutely after CBD, leading to the hypothesis that the recovery of eupneic ventilation following CBD may be associated and/or initiated by activation of the medullary raphe nuclei (MRN). To test this hypothesis, we collected medullary raphe tissue punches (~1mm3) from rats euthanized acutely (1‐2 days) after sham (n=11) or CBD (n=10), or 15 days after sham (n=10) or CBD (n=10) surgery. Eupneic PaCO2 was increased acutely (p<0.001) and chronically (p<0.001) after CBD compared to pre‐CBD control, but PaCO2 15 days post‐CBD was not different than time‐control sham rats demonstrating recovery following CBD. Total RNA was collected using a phenol‐chloroform extraction protocol and quantified/qualified using an Agilent Bioanalyzer. 100 – 600 ng of total RNA was collected with an integrity number of 7 or greater for all samples, indicating high RNA quality. 12 cDNA libraries were created (3 or 4 per group x 4 groups) using the Illumina TruSeq RNA Sample Prep LS protocol for mRNA sequencing, from which all 12 libraries yielded pure cDNA. Ongoing mRNA sequencing will allow for the eventual coupling of our comprehensive physiologic measurements with raphe gene expression to provide unique insights into potential mechanisms of recovery or plasticity ventilatory control after CBD.

Grant Funding Source: Supported by NIHHL097033, T32HL007852.
Ventilatory and metabolic changes in a mouse model of chronic lung disease (713.9)
Authors: Do Jennifer , Powell Frank , Trisko Breanna , Rich Benjamin , Breen Ellen
Published: June 2021

We measured changes in ventilatory and metabolic responses to acute hypoxia and hypercapnia in a mouse model of chronic lung disease. Baseline measurements were made before any treatment. Then we deleted vascular endothelial growth factor (VEGF) in the lungs using the Cre‐loxP strategy. Lungs of VEGF‐lung null mice were treated with adeno‐associated virus (AAV) expressing Cre‐recombinase; control mice were treated with AAV‐LacZ. Measurements were made 1 month later. Then we exposed mice to cigarette smoke (CS, 10 cigarettes/day, 5 days/wk via a nose‐only exposure system) and repeated measurements after 2 and 4 months. VEGF‐lung null and control mice gained weight for 1 month but both groups lost weight during the first 2 months of CS and gained weight by 4 months of CS. Ventilation decreased in normoxia or hypercapnia similarly in VEGF‐lung null and control mice after 4 months CS mainly because of decreased tidal volume. Ventilation normalized for CO2 production shows the same trend so arterial PCO2 should increase. More ventilatory and arterial blood gas measurements are planned after 6 months of CS to quantify the effects of this treatment on pulmonary gas exchange.

Grant Funding Source: Supported by NIH RO1 HL‐081823, P01 HL‐091830
Hydrogen sulfide mimics hypoxic respiratory depression in the isolated brainstem of bullfrogs (Lithobates catesbeianus). (714.3)
Authors: Peacham Thomas , Hedrick Michael
Published: June 2021

Previous studies have shown that hypoxia causes a significant depression or cessation of fictive breathing in post‐metamorphic and adult bullfrog brainstems. We tested the hypothesis that hydrogen sulfide (H2S)contributes to the hypoxic‐induced inhibition of fictive breathing in the isolated bullfrog brainstem. Our hypothesis is based on findings that H2S contributes to hypoxia‐induced reflexes in vascular tissue and may be an important oxygen‐sensing signaling molecule. Brainstems from adult L. catesbeianus were placed in a recording chamber at room temperature (22 °C) and superfused continuously with an artificial CSF (aCSF) bubbled with 98% O2/2% CO2 (control), hypoxic aCSF (98% N2/2% CO2) or sodium sulfide (Na2S ∙ 9H2O ‐ a H2S donor) in control aCSF. Fictive breathing was recorded with suction electrodes applied to cranial nerves that normally innervate respiratory muscles. Brainstem hypoxia caused a significant reduction of fictive breathing from 10 ± 0.4 bursts/min (pre‐hypoxia) to 0.1 ± 0.1 bursts/min (hypoxia). Sodium sulfide (100 μM) caused a similar reduction of fictive lung bursts from 9.3 ± 7.2 bursts/min (pre H2S) to 0.1 ± 0.1 bursts/min (H2S). The results indicate that hypoxia inhibits fictive breathing in the isolated L. catesbeianus brainstem, and that H2S mimics the response to hypoxia. Hydrogen sulfide may be a key molecule for the hypoxia‐induced respiratory depression in the amphibian brainstem.
Vascular hyperreactivity in a rat model of bronchopulmonary dysplasia (715.2)
Authors: Shuster Taylor , Bates Melissa , Kleinertz Aaron , Mahan Sidney , Eldridge Marlowe
Published: June 2021

Bronchopulmonary dysplasia (BPD) develops in ~30% of premature infants and is associated with decreased alveolar and vascular development. We hypothesized that BPD is also associated with vascular hyperreactivity to hypoxic and hyperoxic challenges. A rat model of BPD was created by exposing newborn Sprague Dawley rats to 95% O2 (BPD) for 8 days after birth. Controls (CTL) were exposed to 21% O2. At 21‐25 days old, rats were anesthetized and a Millar conductance catheter was inserted into the left ventricle to obtain cardiac output. A fluid‐filled catheter was inserted into the right ventricle (RV) to measure pressure. Rats were ventilated with 100% O2 (10 min), and 10% O2 (10 min) and pulmonary vascular resistance (PVR) was calculated for each condition by dividing the RV pressure by cardiac output. BPD rats had RV hypertension at baseline compared to CTL (31±5 mmHg vs 16±2 mmHg, p=0.028), largely caused by increased cardiac output. Contrary to our hypothesis, BPD rats demonstrated little change in PVR to hypoxia and hyperoxia, suggesting that vascular reactivity is impaired in BPD. Given the observed baseline RV hypertension in the BPD group, our future studies will aim to investigate the impact on myocardial contractility in this model.

Grant Funding Source: Supported by NIH 5R01HL115061
Methylene blue protects against oleic acid‐induced acute lung injury in rats (718.2)
Authors: Silveira Ana Paula , Albuquerque Agnes , Vento Daniella , Nadai Tales , Neves Ariadne , Campos Débora , Celotto Andrea , Évora Paulo
Published: June 2021

We aimed to evaluate the methylene blue (MB) effects in the lung tissue, with emphasis on capillary permeability, inhibiting the soluble guanylate cyclase (sGC) in oleic acid‐induced (OA) acute lung injury (ALI). Male Wistar rats under spontaneous breathing received 1) OA (100 or 200 mg/kg); 2) Pretreated group received MB 5 min before the OA infusion, and; 3) Treatment group received MB 2 hours after OA infusion. The MB was administered as an i.v. bolus followed by 2h of continuous infusion (3mg/kg/h). After 4 h, blood was collected for gasometry; bronchoalveolar lavage for total protein dosage and lung tissue for wet weight/dry weight (W/D) analysis, histology and amount of tissue nitric oxide (NO). ALI was characterized by the OA of 200mg/kg, the increased bronchoalveolar lavage protein and the relation W/D. The main results were: 1) It was not observed severe hypoxemia after 4 hours of ALI; 2) The pre‐treatment group showed a significant difference with lower protein quantification in bronchoalveolar lavage; 3) Although not statistically significant it was observed lower values of the W/D ratio and NO tissue in the MB groups; 4) Gross examination of the lungs revealed more severe injury in the untreated group, confirmed by histological examination whose main findings include increased infiltration of lymphocytes, alveolar membrane thickening and increased alveolar edema. These data suggest that the lung permeability decreases when MB is administered at an early stage OA‐induced ALI.

Grant Funding Source: Supported by CNPq
Case report: left superior vena cava with associated heart and venous anomalies (719.13)
Authors: Schoenhals Sarah , Trane Ashley , Roberts Chad , Saunders Jacob , Morton David
Published: June 2021

Cadaveric dissection by first year medical students is an important educational tool in learning normal anatomy, however dissection also provides the opportunity to discover anatomical variations. During a routine heart dissection of a 61‐year‐old male cadaver the superior vena cava (SVC) was found to be on the left side (LSVC), with an absent right SVC. The right brachiocephalic vein passed from right to left to join the left internal jugular and subclavian veins at the LSVC. Upon removal of the heart, it was found that a portion of the right atrium circumscribed posteriorly to the left atrium, where the LSVC entered and connected to an unroofed coronary sinus. The azygos vein presented on the left with a hemiazygos vein on the right. Discovery of this rare anomaly provides a learning tool by exploring its embryological origins and clinical relevance (such as challenges with surgery and placing central lines).
Why should we study evidence‐based medicine? (719.19)
Authors: Tuleshova G. , Shaidarov M. , Derbisalina G. , Sholanova M. , Anasheva D. , Karp L.
Published: June 2021

Evidence‐based medicine in its present form should not be considered only in the context of medical practice, but also as a methodological basis for the world view formation of the modern physician, who aimed to use the experience of the world to meet the challenges all health problems. It is with the training of students at the undergraduate level and advanced training of doctors should begin implementation of the evidence principles in health care, research and clinical activities. The basis of teaching evidence‐based medicine should be based on the principles of a systematic approach and continuity of education throughout the professional life of a physician. Evidence‐based medicine should not be viewed as a separate discipline of the curriculum, but as a set of activities, integrative, gradually preparing the physician to make decisions or focusing it on a constant search for new information to solve health issues. The structure of morbidity rate has changed in favor of the chronic diseases that occur over decades, and medicines treatment and diagnosis of patients became as a huge, plenty of billiondollar business. There is little doubt that the medicine based on evidence ‐ where about it is all about, it is better that it displaces. It is possible that it will be not as effective as we hope, for the production of conclusive evidence requires time consuming, expensive, and probably not feasible at all to the end.
Radiofrequency renal nerve denervation decreases blood pressure, sympathetic activity and renal norepinephrine content in spontaneously hypertensive rats (72.1)
Authors: Gao Juan , Kerut Edmund , Smart Frank , Kapusta Daniel
Published: June 2021

Radiofrequency renal denervation (RF‐RDN) decreases blood pressure (BP) in patients with drug‐resistant hypertension. This study investigated the effects of RF‐RDN on sympathetic activity and BP (Systolic, SBP; Diastolic, DBP) in SHR. Methods Nineteen‐week old male SHR were instrumented with telemetry probes for chronic measurement of BP and BP variability (BPV). After 1‐week, control BP was measured in rats for 3 days. The next day SHR (n=6/group) were anesthetized and randomly received either bilateral Sham‐RDN or RF‐RDN of the renal arteries (Biosense Webster Stockert 70 generator and RF‐probe). BP was then measured in SHR for 8 weeks. Results Following RF‐RDN, SBP/DBP was significantly decreased the day after (153±8/102±4 mmHg) and throughout the post‐RDN study (4‐week SBP/DBP, 173±7/120±5; 8‐weeks, 171±6/116±4 mmHg) compared to pre‐RDN control levels (SBP/DBP, 187±9/130±5 mmHg). RF‐RDN significantly decreased the low frequency component of BPV in SHR with the peak attenuation observed at 8 weeks (LF/HF 2.2±0.2 vs 0.9±0.2); this correlated with a blunting of the hypotensive response to i.p. chlorisondamine in RF‐RDN rats. Finally, at the end of week 8, kidney norepinephrine (NE) levels in RF‐RDN rats (left, 10±10; right, 0.0±0.0 ng/g kidney) were dramatically decreased compared with levels from sham SHR (left, 130±10; right, 110±10 ng/g kidney). Conclusions These data demonstrate that in hypertensive SHR, bilateral RF‐RDN of the renal arteries decreases BP in part by chronic inhibition of sympathetic neural pathways and a decrease in renal tissue NE levels.

Grant Funding Source: Biosense Webster grant IIS‐175 to DRK and FS; NIH NIGMS P20 GM103514 to DK
Functional anatomy labs in a second year medical school musculoskeletal course (721.7)
Authors: Sanders Luke , Barker Jordan , English Joy , Powell Amy , Morton David
Published: June 2021

Many primary care physicians lack the training to adequately conduct the musculoskeletal (MSK) portion of a physical exam. To address this challenge at the University of Utah School of Medicine we devised a series of functional anatomy labs to accompany our five‐week MSK course. Each week of the course was devoted to a different region of the body (spine, hip and knee, ankle and foot, shoulder and elbow, wrist and hand), and the associated labs consisted of six 20‐minute stations which integrated integrated cadaveric prosections, imaging, including hands‐on ultrasound experience, all in the context of MSK phAn. An anatomy professor, laboratory TA, 4th year medical student, or sports medicine physician facilitated. Reported was an increased knowledge and comfort in subsequent clinical MSK rotations.
The Klingler preparation technique and plastination: orienting students to three‐dimensional neuroanatomy (721.9)
Authors: Jilwan Andrew , Shukla Vipul , Baptista Carlos
Published: June 2021

Due to the complexity of the central nervous system, neuroanatomy is cited as one of the most challenging portions of the anatomical sciences to study by first year medical students, and junior physicians alike. Fiber paths are challenging to visualize to their full extent, and it is difficult for a novice learner to clearly dissect them. Interpretation of a two‐dimensional image to a three‐dimensional anatomical structure is a daunting task, and creates palpable dread to many students.

Since its inception, plastination has served as an adjunct in teaching anatomy. If used properly, plastinated specimens can augment students' understanding of neural architecture. Brains dissected following the preparation method by Klingler can be plastinated and utilized for visualization of fiber paths, and used to accent complex structures. This technique can isolate neuroanatomical structures that students often have trouble visualizing in three dimensions, such as the corpus callosum. This poster will discuss the specimen preparation technique, as well as assessing the potential benefits for orienting students to three‐dimensional neuroanatomy.
Next generation anatomy: integrating whole genome sequencing within the human anatomy curriculum (723.2)
Authors: Kumar Akash , Smith Kelly , Clark John , Shendure Jay , Horwitz Marshall
Published: June 2021

Advances in genomics have vastly outpaced clinical education in this area. To help address this problem, the UW has piloted the introduction of whole genome sequencing within our first year human anatomy course.

Last year, thirteen first‐year medical students performed whole genome sequencing and analysis of a cadaver during the anatomy course. The patient expired with a diagnosis of idiopathic pulmonary fibrosis. Students participated in a dissection of the cadaver, and a pathologist highlighted the anatomical changes resulting from the disease. Students then worked collaboratively to complete a ~45× whole genome sequence and then analyzed this patient’s genome using various bioinformatics tools. The analysis identified a variant in mucin‐encoding MUC5B that was recently associated with pulmonary fibrosis.

A year later, these students presented their findings to small groups (<20 students) of the new first year students and discussed the patient’s clinical history, the results of the dissection and genome sequencing.

Our experience demonstrated the value of introducing whole genome sequencing within anatomy as an early entry point for establishing genotype‐phenotype associations in medical education.

Grant Funding Source: Funding provided by University of Washington MSTP
Video game and mental rotation training improve spatial anatomy task scores (725.5)
Authors: Lapaine Pierre , Johnson Marjorie , Nguyen Ngan
Published: June 2021

High scores in measures of mental rotation have been associated with improved spatial anatomy performance. Mental rotation training, such as video games as well as paper‐and‐pencil mental rotation tasks, has been shown to improve mental rotation scores. The purpose of the study is to determine whether video game or paper‐and‐pencil mental rotation training can improve spatial anatomy ability.

Participants in the study (n=13), either medical or dental students, were asked to complete the Mental Rotations Test (MRT) and the Spatial Anatomy Task (SAT) to provide a baseline measure of their spatial ability and spatial anatomy knowledge, respectively. Based on MRT scores, participants were assigned to one of three groups: one that played 5 cumulative hours of the video game Tetris (n=3), another that completed the MRT daily over the span of a 5 days (n=4), and a control group that received no training (n=5). All participants were again asked to complete the MRT and SAT after training. Paired t‐tests were used to compare baseline and final test scores in each group.

Preliminary results show that both the MRT group (p = 0.046) and the Tetris group (p = 0.014) significantly improved their total SAT scores, while the control group (p = 0.129) did not. Although more research is necessary to make definitive conclusions, the current study indicates that mental rotation training may be of benefit for students learning spatial anatomy.
Prenatal ethanol exposure reduces pyramidal cell size and postsynaptic density length in the CA1 region of the hippocampus in adolescent rats (726.2)
Authors: Lindsay Brianne , Patten Anna , Christie Brian , Nahirney Patrick
Published: June 2021

Fetal alcohol spectrum disorder (FASD) is the leading cause of cognitive impairment in the Western world. The impact of the toxic effects of prenatal ethanol exposure (PNEE) on the development of memory regions of the brain remains unclear. To understand these effects, a rat model of PNEE was used to study structural elements of cornu ammonis 1 (CA1) of the hippocampus. Using light and electron microscopy, the density and size of pyramidal cell nuclei and synapses in the CA1 were quantified by morphometric methods in control and PNEE male rats at postnatal day 35 (P35). During gestation the blood alcohol content of pregnant dams ranged from 90‐150 mg/dl and average body weight of PNEE offspring rats was ~15% less than controls at P35. By light microscopy, the pyramidal nuclear area (as a measure of cell body size) was reduced by ~22% in PNEE rats when compared to controls (105.1 ±15.1 µm² vs 135.2 ±4.65 µm²). By electron microscopy, the spine shape and density of synapses within stratum radiatum was not significantly different between the two groups, however, the total combined length of post‐synaptic densities (PSDs) per test field (117µm²) was significantly less in PNEE rats (2157 ±121 nm vs 2523 ±192 nm, p<0.025, n=30 fields/group). These results indicate ethanol exposure in utero affects the size of pyramidal nuclei and overall receptive fields (PSDs) in adolescent PNEE rats and points to permanent effects or delays in maturation in the CA1 region of the hippocampus.

Grant Funding Source: Supported by NSERC
Menstrual cycle change in thalamic glutamate decarboxylase and GABA in response to TMJ pain in rats (726.4)
Authors: Umorin Mikhail , Bellinger Larry , Kramer Phillip
Published: June 2021

Women report TMJ pain more often than men and epidemiological evidence suggests the pain response varies between men and women and over the menstrual cycle. Recent studies show TMJ responsive neurons projecting to the thalamus have different activities in male and females. Using a rat model our lab performed whole genome array screens on thalamic tissue of cycling rats. The results indicate that the transcript of both glutamate decarboxylase 1 and 2 (GAD67 and GAD65, respectively) are significantly up‐regulated in the thalamus of proestrus (high estrogen, progesterone and luteinizing hormone concentration) versus diestrus/metestrus (low estrogen, progesterone and luteinizing hormone concentration) rats. On the other hand, GABA expression (by ELISA assay) did not significantly change in the thalamic tissue during the proestrus phase. The differences in response of the enzyme and its product could be explained by the distribution of each enzyme within individual neurons. In conclusion, sex steroids could alter thalamic GABAergic signaling to effect TMJ hyperalgesia through regulation of GAD.

Grant Funding Source: Supported by NIH R01 NIDCR grant: DE022129 Estrogen and TMJ Pain
An anatomical update of the aortic plexus with clinical implications for retroperitoneal surgery (726.6)
Authors: Beveridge Tyler , Johnson Marjorie , Power Adam , Power Nicholas , Allman Brian
Published: June 2021

The aortic plexus is a sympathetic network of pre‐ and post‐ganglionic nerves overlying the abdominal aorta. The literature minimally describes the anatomy of this plexus and little research has been completed to anatomically define the nerves of this plexus. This study aimed to anatomically map the aortic plexus through dissection of fresh, frozen human cadavers (n=7). Using standard histochemical procedures, ganglia of the aortic plexus were verified with H&E staining and anti‐tyrosine hydroxylase staining confirmed the presence of sympathetic neurons. All specimens (100%) had 4 distinct ganglia that were supplied by right and left, L1 and L2 lumbar splanchnic nerves; 3 documented ganglia (right/left spermatic ganglia and inferior mesenteric ganglion), and 1 previously‐unidentified ganglion. Moreover, the prevalence of the accessory splanchnic nerves (right/left accessory L1 lumbar splanchnic 29%/29%; right/left accessory L2 lumbar splanchnic 14%/86%) and pre‐aortic nerves (inferior branch of right spermatic 86%; right/left intermesenteric nerve 29%/71%) were documented in each specimen to assess variability in the plexus. Clinically, our results could have implications for preserving fertility in men and sympathetic function to the hindgut and pelvis during retroperitoneal surgeries.

Grant Funding Source: Supported by Canadian Urology Association Scholarship Foundation Grant
Immunohistochemical staining for neurotransmitter‐related antigens in nerves fixed with high concentrations of glutaraldehyde (726.7)
Authors: Carvalho Carolina , Castania Jaci , Salgado Helio , Fazan Valéria Paula , Llewellyn‐Smith Ida
Published: June 2021

Immunohistochemistry (IHC) demonstrates specific antigens within tissues or cells and is usually done on formaldehyde‐fixed tissues. However, for a detailed quantification of axons within nerve bundles, glutaraldehyde fixation is mandatory. We aimed to develop an IHC technique for nerves fixed with high concentrations of glutaraldehyde. Phrenic nerves from 8 male Wistar rats were removed, fixed in phosphate‐buffered 2.5% glutaraldehyde and cryoprotected in 30% sucrose. Slide‐mounted cryostat sections (16 µm thick) were incubated for 24 hr in goat polyclonal anti‐choline acetyltransferase (ChAT; 1:1,000) or rabbit polyclonal anti‐substance P (SP; 1:10,000) then transferred to biotinylated donkey anti‐goat or donkey anti‐rabbit immunoglobulin (1:500; 24 hr) before immersion in Extravidin‐HRP (1:1.500; 24 hr). Immunoreactivity in axons was revealed with a nickel‐intensified diaminobenzidine reaction. This method reproducibly revealed individual axons that contained immunoreactivity for ChAT or SP within the phrenic nerve. These results show that peptides and large proteins can be detected by IHC in nerves that have been immersion‐fixed in a high concentration of glutaraldehyde. This method is reliable for identifying neurotransmitter‐related antigens and will allow quantification of axons with specific physiological roles, which can be inferred from their neurochemical phenotypes.

Grant Funding Source: FAPESP, CAPES, CNPq and FAEPA
State‐ and vagal‐dependent modulation of augmenting pattern of phrenic nerve discharge during eupnea in rats (726.8)
Authors: Ghali Michael , Fuller David , Marchenko Vitaliy
Published: June 2021

Pontomedullary nuclei interact to generate and shape the respiratory rhythm and pattern, which is relayed to and modified in cranial and spinal respiratory motor outputs, including the phrenic nucleus, the motoneurons of which form the phrenic nerve and innervate the diaphragm. Under normal conditions, phrenic nerve discharge during eupnea is typified by an initial augmenting (ramp‐like) rising phase of inspiratory activity peaking in late‐inspiration, representing an orderly spatiotemporal recruitment of phrenic motoneurons. We tested the hypothesis that phrenic ramp is state‐ and vagal‐dependent. Experiments were performed on twenty‐one Sprague‐Dawley adult male rats. Groups included anesthetized vagus‐intact (n=6), decerebrate initially vagus‐intact (n=14), and decerebrate initially vagotomized (n=1) animals. Of the decerebrate initially vagus‐intact animals, a group was vagotomized (n=5) and another (n=7) was re‐anesthetized with isoflurane (2%) during continuous phrenic nerve recordings. This allowed comparisons to be made between animal groups as well as within the same animal to examine the effects of anesthesia and vagotomy on phrenic pattern. Three measures were primarily used to quantitatively represent phrenic burst shape ‐ 1) the fractional time of occurrence of peak integrated activity relative to inspiratory duration, 2) the peak‐to‐root‐mean‐square of burst amplitude, and 3) the relative proportion of total burst power contained in the fraction of the inspiratory epoch preceding peak integrated activity. Both anesthesia and vagotomy resulted in a statistically significant decrease in all three measures of phrenic ramp as well as an increase in cycle‐to‐cycle variability of phrenic burst shape. We conclude that the augmenting pattern of phrenic nerve discharge and its cycle‐to‐cycle consistency is both state‐ and vagal‐dependent.
Cadaveric investigation into the innervation of the long head of triceps brachii (726.9)
Authors: Erhardt Alexandra , Futterman Bennett
Published: June 2021

All three heads of the Triceps brachii are classically described as being innervated by the radial nerve. A previous study of 20 cadaveric shoulders revealed that in 13 specimens the long head of the triceps (LHT) was supplied by a branch of the axillary nerve, not the radial nerve. In our current study 20 cadaveric shoulders were dissected via a combined anterior and extensile dorsal approach. The dissections were photographed and nerve maps were created. Distances from proximal LHT attachment to the point of neuromuscular insertion were measured with calipers. The results indicated that in 60% of the specimens the axillary nerve contributed to the innervation of the LHT; in 15% axillary nerve alone and in 45% combined axillary and radial nerve. These findings have clinical significance in understanding why triceps brachii dysfunction is sometimes associated with axillary nerve injuries.
Examining the function of TPX2 during neurite morphogenesis (727.2)
Authors: Hwang Eric , Chen Wen‐Shin , Chen Yi‐Ru , Huang Yung‐An
Published: June 2021

A functional nervous system depends on the intricate connections between neurons. To establish appropriate connections between neurons, the morphogenetic process of the neuron must be carefully regulated. Neuritogenesis is the morphogenetic process that regulates neurite extension and connection. It has been shown that the microtubule cytoskeleton and microtubule‐associated proteins are indispensable for this process. The microtubule‐associated protein, targeting protein for Xklp2 (TPX2) plays critical roles during mitosis. TPX2 is required to generate a stable bipolar spindle. It localizes to the nucleus during interphase and to the spindle poles during mitosis. We previously identified TPX2 as one of the most abundant proteins on neuronal microtubules, suggesting that TPX2 may play a role during neuritogensis. To examine the function of TPX2 in neurons, we depleted TPX2 in mouse primary hippocampal neurons using shRNA and observed a decrease in neurite length and branching number, suggesting TPX2 is involved in the neurite elongation and branching process. To determine the mechanistic basis of TPX2 on these processes, we examined the localization of TPX2 in hippocampal neurons. We observed that TPX2 localized primarily to the centrosome and interacted with gamma‐tubulin. Additionally, TPX2 also distributed in the neurites and bound to the microtubule cytoskeleton. To determine how TPX2 affects the microtubule cytoskeleton, we analyzed the dynamics of microtubules in TPX2‐depleted neurons by examining the microtubule plus‐end binding protein EB3. However, we did not observe any change in microtubule plus‐end dynamics or microtubule emanating frequency in TPX2‐depleted neurons. These results indicate that TPX2 participates in the neuritogenesis process and may exert its effect via neurite‐localized and microtubule‐bound population.

Grant Funding Source: Supported by National Science Council of Taiwan
Vitamin D3, testosterone, epigenetics, and nocioception: an evolving concept of neurohomeostasis (727.3)
Authors: Seigel Eric , Thomas Marc , Tulp Orien , Einstein George
Published: June 2021

To determine the effects of hormonal contributions to neurosignaling and clinical pain management, a study was undertaken to correlate the effects of plasma concentrations of vitamin D3, Testosterone, markers of epigenetics, and nocioception on outcomes via meta analysis of existing studies. Vitamin D3 and Testosterone have long been shown to be linked to molecular expression of numerous gene products, including calbindin, the homer‐1 gene, cytochrome P24, cytochrome P27, Bone Morphogenetic Proteins [BMPs] and others, all of which are proposed to have supporting molecular roles in neurophysiologic processes and in nocioception. The clinical descriptions that directly link Vitamin D3 or testosterone to pain are inconsistently linked, however, but the composite effects of relevant studies support an emerging concept of nocioceptive homeostasis and neuroplasticity that is in part epigenitcally mediated emerge, and thus include a likely contributory role for steroid hormones in the process of nocioception and certain clinical elements of pain management.

Grant Funding Source: Institutional Resources
Style changes in time‐coded stream‐of‐consciousness handwriting identifies real‐time mood fluctuations in mania (728.19)
Authors: Jennings Marcus , Canolty Nancy
Published: June 2021

Methods to experimentally assess changes in mood are limited. In this case study real‐time mood fluctuations in mania were measured by evaluating, without regard to content, changes in time‐coded stream‐of‐consciousness writing style during a 29‐day manic episode experienced and recorded by one of the authors (nlc). Mood was judged to be in flux when text script changed from linear to non‐linear with the time point of the change being the cusp between the two writing styles. Handwritten in 13 bound journals were 54,580 words, with 21,918 of them (40%) written in the episode’s first quadrant, 16,287 (30%) in the second, 10,475 (20%) in the third, and 5,900 (10%) in the final quadrant. There were 195 writing style cusps, with 17% occurring in the first quadrant, 48% in the second, 30% in the third, and 5% in the fourth. These time‐coded writing style cusps denoted real‐time mood fluctuations during the manic episode. Even though the most words were written in the first quadrant, mood fluctuations as measured by writing style cusps were greatest in the second quadrant. This case study demonstrates that mood fluctuations in mania can be objectively studied by analyzing time‐coded stream‐of‐consciousness handwriting. Comparison of writing style cusps across time could help evaluate mania mood fluctuations to determine the need for or the efficacy of pharmaceutical and/or behavioral management protocols.
Myelinated fiber distribution in the aortic depressor nerve of male and female spontaneously hypertensive rats (728.22)
Authors: Amorim Milena , Castania Jaci , Salgado Helio , Fazan Valéria Paula
Published: June 2021

Aortic depressor nerve (ADN) is an afferent nerve that contains myelinated (fast conducting) and unmyelinated (slow conduction) fibers that send information from aortic mechanoreceptors to central nervous system [1]. Previous studies form our laboratory [2,3] in spontaneously hypertensive rats (SHR) have demonstrated morphological alterations on the ADN in SHR, using male and female animals indistinctively. In this study we investigated the ADN fiber distribution comparing male and female adult (20 weeks old) SHR. After the (AP) and heart rate (HR) recordings, together with the ADN spontaneous activity, the left ADN were prepared for light microscopy and morphometry. Myelinated fiber distributions were compared between proximal and distal segments in the same gender and between genders. Myelinated axon and G ratio distributions were also investigated. Myelinated fiber diameter range from 1 to 5 µm, with peak (~40% of fibers) at 2 µm while myelinated axon size range from 0.5 to 4 µm, with peak (~50% of axons) at 1.5 µm. No differences were observed between segments or genders. This indicates that gender does not influence on the ADN myelinated fiber size, allowing the use of male and females for morphological studies.

[1] Krieger and Marseillan, Am J Physiol, 1963:205; [2] Fazan et. al, J Auton Nerv Syst 77, 1999:133; [3] Fazan et. al, Am J Physiol Heart Circ Physiol 280,2001:H1560.

Grant Funding Source: FAPESP, CAPES, CNPq and FAEPA
Structural, morphologic and morphometric study of the phrenic nerve: association between experimental diabetes and arterial hypertension (728.24)
Authors: Ferreira Renata , Rodrigues Anaceres , Castania Jaci , Salgado Helio , Fazan Valéria Paula
Published: June 2021

Although the association between hypertension and diabetes is common in clinical practice, it is not well known the contribution of each of these diseases in the development of diabetic neuropathy in patients with hypertension. We investigated the presence of peripheral neuropathy, through morphology and morphometry analysis of the phrenic nerve in normotensive rats (Wistar) and spontaneously hypertensive rats (SHR) with experimentally induced chronic diabetes. Diabetic animals received a single injection of streptozotocin (STZ) intravenously while controls received vehicle on the same date. Twelve weeks after injection, arterial pressure and heart rate were recorded and the right and left phrenic nerves were removed and prepared for embedding in epoxy resin and computer morphometry. The phrenic nerves of SHR and diabetic SHR (SHR + STZ) showed reduced number and density of myelinated fibers and Schwann cell nuclei, compared to Wistar. The SHR and SHR+STZ rats showed myelinated fiber size distributions skewed to the right, with an important reduction of the small myelinated fibers. This finding was more pronounced on diabetic SHR when compared to normotensive diabetic animals. We suggest that hypertension causes a reduction of small myelinated fibers and the association of the hypertension and diabetes did not interfere with the small fiber neuropathy present in the hypertensive animals.

Grant Funding Source: CAPES, FAPESP, CNPq and FAEPA
3D printing from MRI data of stroke and Alzheimer’s disease subjects: an educational model of neurologic disease (728.4)
Authors: Gardiner Brett , Wisco Jon
Published: June 2021

Normal human anatomy used in the classroom is not reflective of variations confronted in pathology subjects. Current commercialized models are not products of real data, rather representations of it. While learning complicated medical anatomy, students take an enormous leap from the anatomy lab to situational surgical settings. 3D models can bridge this gap in medical education without patient risk, particularly for the brain where surface regions have strong associations to specific physiological activity. Subject specific models are especially advantageous for comprehending real surface morphology of neurologic diseases. Using rapid prototype (RP) technology, we have developed an accessible process to produce physical 3D models from specific MRI data of stroke and Alzheimer’s subjects. The neuroanatomical abnormalities modeled from real data by our 3D printouts will educate students on the anatomical variations encountered in an authentic clinical scenario of neuropathology. Our methods consisted of three phases: (1) image acquisition, (2) post‐processing imaging data with segmentation, and (3) 3D printing. By delineating cortical regions we have provided a unique multidimensional facet of clinically accurate data not yet available to the classroom. This powerful and versatile technique allows students and professionals to visualize the inherently complicated structures as seen in clinical neuropathology. From students in the classroom, lawyers in the courtroom or preoperative surgical explanations, these customizable models resemble real anatomical information. RP from specific subject data allows educational review of the unique clinical variations encountered in pathology.

Grant Funding Source: Mentoring Research Grant, College of Life Sciences, Brigham Young University
The efficacy of ultrasonography in the evaluation of the posterior interosseous nerve for the diagnosis of neuropathy (728.5)
Authors: Raeburn Kazzara , Wear Christopher , Burns Danny , Tubbs R Shane , Loukas Marios
Published: June 2021

Ultrasound technology has become indispensible in the diagnosis of many neuropathies including those of the posterior interosseous nerve. Posterior interosseous nerve neuropathies have many causes notably entrapment beneath the arcade of Froshe, compression by tumors, ganglia or aberrant blood vessels. The literature regarding the anatomy of this nerve elucidates a caliber change in the long axis of the nerve as it pierces the supinator muscle. This seemingly physiological compression may be misinterpreted as entrapment. The aim of this study was therefore to evaluate the longitudinal and cross sectional anatomy of the posterior interosseous nerve at key anatomical landmarks taken from cadaveric specimens and ultrasound of normal adults. Thereby determining the reliability of ultrasound in the evaluation of compression pathologies of the posterior interosseous nerve. Longitudinal and cross sectional measurements of the radial nerve of 50 healthy adults and 30 cadaveric dissections were taken at specific intervals. Logiq E ultrasound unit with a 12Hz linear array transducer was used. Both patients and cadavers were screened for previous surgeries of the area and excluded if visible signs of intervention was present. Visualization of the cross sectional anatomy during ultrasound is challenging and measurements obtained are not directly comparable with that taken on the cadavers. However a size change was noted in the longitudinal axis but no significant difference in the cross sectional area of the nerve could be established. Ultrasonography is commonly used in diagnostics and has become an important tool in diagnosis of entrapment neuropathies among many others. Physiological compression as the nerve pierces the muscle seen on ultrasound should not be misconstrued as nerve entrapment and other modalities should be used to confirm diagnosis before surgery is performed.
Th17 pathway genes are primarily downregulated by spinal cord injury (729.4)
Authors: Jones T Bucky , Jones Carleton
Published: June 2021

Spinal cord injury (SCI) elicits a neuroinflammatory response involving cells of both innate and adaptive immunity. A new subtype of T‐helper cells, Th17, plays a role in several neuroinflammatory pathologies including multiple sclerosis and stroke. We therefore examined the role of Th17 cells in neuroinflammation secondary to SCI. Quantitative reverse transcriptase‐polymerase chain reaction (qRT‐PCR) arrays were used to evaluate postinjury expression of 84 genes relating to the Th17 pathway in a rat model of SCI. At 7 days post injury (dpi) mRNAs of 18 genes were increased and 27 were decreased compared to controls. Of these, 4 genes remained up‐ and 15 downregulated at 28 dpi. Although the genes for TGF‐β1 and IL‐6, cytokines required for differentiation of Th17 cells, were both upregulated at 7 dpi this was not associated with increased IL‐17. Indeed, Rorc, IL‐17b, and IL‐17f mRNAs were all decreased while IL‐17a and IL‐17c mRNAs were unaffected by injury. This was perhaps because IL‐23a, required for the survival and proliferation of Th17 cells, was also decreased. Similar effects were observed at 28 dpi, although generally lesser in magnitude. Although Th17 cells and the IL‐17 family of cytokines mediate cross talk between adaptive and innate immunity in many pathologic conditions, our data do not support a role for this T‐cell subset in the chronic inflammatory response to SCI.
Signs of persistent neuroinflammation after myocardial infarction of mice (730.3)
Authors: Gouweleeuw Leonie , Pol Christine , Zuidwijk Marianne , Simonides Warner , de Jongste Mike , Eisel Ulrich , Schoemaker Regien
Published: June 2021

Acute myocardial infarction (MI) evokes production of circulating pro‐inflammatory cytokines, which can result in neuroinflammation. This study aimed to investigate signs of neuroinflammation in mice by measuring brain TNF‐alpha expression and microglia activation after MI.

Male 14 week old C57 Bl/6 mice were subjected to MI or sham surgery. Two weeks later, infarct was verified by ECHO‐cardiography, and mice were sacrificed. Brain was processed for western blot on TNF‐alpha, and TNF‐receptors.

Heart failure in MI mice was confirmed by increased lung dry weight (35.2±2.2 vs 30.1±0.7 mg), and reduced fractional shortening (19±3 vs 46±1%). TNF‐alpha precursor expression was significantly increased in MI versus sham (9.79±0.60 vs 6.99±0.64 AU) and was associated with higher TNF‐R1 (5.92±2.39 vs 1.88±0.36 AU) and lower TNF‐R2 expression (0.71±0.61 vs 3.01±0.95 AU). Brain tissue stained for microglia showed increased numbers of microglia in the dentate gyrus of the hippocampus (17.1±0.8 vs 14.7±0.8 per high power field) combined with a decreased ratio of processes/cell body surface area (0.071±0.004 vs 0.098±0.007), indicating a higher degree of activation.

MI in mice induces increased TNF‐alpha expression at higher TNF‐R1 and lower TNF‐R2 expression in the brain, indicating a persistent pro‐inflammatory state. Spatially altered number of microglia may suggest localization of this inflammation.