bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Establishment of Peripheral Sensory Arbors in the Leech:In VivoTime-Lapse Studies Reveal a Highly Dynamic Process
Authors: Wang Huajun , Macagno Eduardo R. 
Published: April 2018

Pressure-sensitive (P) neurons located in the leech CNS form elaborate terminal arbors in the body wall of the animal during mid-embryogenesis. In the experiments discussed here, arbor development in the target region was studied in intact, unanesthetized leech embryos using time-lapse video microscopy of individual, fluorescently stained P neurons. Analysis of time-lapse recordings made over a period of several days revealed that arbor formation is a very dynamic process. At any particular time, most high-order terminal branches were either extending or retracting, in approximately equal numbers and at very similar rates. Many branches underwent several rounds of extension and retraction every hour. Net arbor growth occurred at a much lower rate than the extension and retraction rates of individual branches. Process retraction sometimes resulted in an apparent change in the topological order of processes. Significantly, the initiation of new branches was restricted to a few locations along the parent process, which were termed “hot spots.” Moreover, the capacity to generate high-order branches correlated with parent process stability.The target region of the growing P cell arbor in the body wall was subsequently examined using confocal microscopy in fixed preparations. The arbor expanded between the longitudinal and circular muscle layers, a region occupied by small unidentified cells. Simultaneous imaging of the dye-labeled terminal arbor and the surrounding tissue at two different wavelengths suggested that the high-order processes were navigating around these cells, which sometimes forced the growing processes to assume a bent form.These observations suggest that the formation of the P cell arbor can be best described as a “dynamically unstable” process that is constrained by interactions with its environment.
Dynamic Microtubule Ends Are Required for Growth Cone Turning to Avoid an Inhibitory Guidance Cue
Authors: Challacombe Jean F. , Snow Diane M. , Letourneau Paul C. 
Published: April 2018

Growth cone turning is an important mechanism for changing the direction of neurite elongation during development of the nervous system. Our previous study indicated that actin filament bundles at the leading margin direct the distal microtubular cytoskeleton as growth cones turn to avoid substratum-bound chondroitin sulfate proteoglycan. Here, we investigated the role of microtubule dynamics in growth cone turning by using low doses of vinblastine and taxol, treatments that reduce dynamic growth and shrinkage of microtubule ends. We used time-lapse phase-contrast videomicroscopy to observe embryonic chick dorsal root ganglion neuronal growth cones as they encountered a border between fibronectin and chondroitin sulfate proteoglycan in the presence and absence of 4 nmvinblastine or 7 nmtaxol. Growth cones were fixed and immunocytochemically labeled to identify actin filaments and microtubules containing tyrosinated and detyrosinated α-tubulin.Our results show that after contact with substratum-bound chondroitin sulfate proteoglycan, vinblastine- and taxol-treated growth cones did not turn, as did controls; instead, they stopped or sidestepped. Even before drug-treated growth cones contacted a chondroitin sulfate proteoglycan border, they were narrower than controls, and the distal tyrosinated microtubules were less splayed and were closer to the leading edges of the growth cones. We conclude that the splayed dynamic distal ends of microtubules play a key role in the actin filament-mediated steering of growth cone microtubules to produce growth cone turning.
The 5-HT3Receptor Is Present in Different Subpopulations of GABAergic Neurons in the Rat Telencephalon
Authors: Morales Marisela , Bloom Floyd E. 
Published: April 2018

The type 3 serotonin receptor (5-HT3R) is a ligand-gated ion channel whose presence in the CNS has been established by radioligand binding,in situhybridization, and immunohistochemical analysis. To analyze further the role of the 5-HT3R in the CNS, we usedin situhybridization and immunocytochemistry to determine that 5-HT3R-expressing neurons are mainly GABA-containing cells in the rat telencephalon. We determined that 5-HT3R/GABA-containing neurons do not exhibit somatostatin immunoreactivity but often contain cholecystokinin (CCK) immunoreactivity. 5-HT3R-expressing cells with CCK immunoreactivity were observed in the neocortex, olfactory cortex, hippocampus, and amygdala. The 5-HT3R/CCK interneurons represent between 35 and 66% of the total population of CCK-containing cells in the neocortex.Further characterization of the 5-HT3R/GABAergic neurons was based on their calcium-binding protein immunoreactivity and showed that these neurons lack parvalbumin (PV) and represent a subpopulation of calbindin (CB)-containing interneurons that were preferentially present in the CA1–CA3 subfield of the hippocampus. Although some 5-HT3R/GABAergic neurons with calretinin (CR) were found in the neocortex, olfactory cortex, hippocampus, and amygdala, these neurons were more often present in the agranular insular and piriform cortices.We conclude that the neuronal expression of the 5-HT3R is selective within the GABA neuron population in the rat telencephalon. These 5-HT3R-expressing interneurons might contain CCK, CB, and CR. We suggest that serotonin through the 5-HT3R may regulate GABA and CCK neurotransmission in the telencephalon.
Inhibition of Stress-Induced Neuroendocrine and Behavioral Responses in the Rat by Prepro-Thyrotropin-Releasing Hormone 178–199
Authors: McGivern Robert F. , Rittenhouse Peter , Aird Fraser , Van de Kar Louis D. , Redei Eva 
Published: April 2018

A corticotropin release-inhibiting factor (CRIF) in brain has been postulated for several decades, based on increased plasma levels of ACTH and corticosterone after hypothalamic–pituitary disconnection. Recentin vitrostudies indicate that prepro-TRH178–199 may function as an endogenous CRIF, prompting us to examine stress-related neuroendocrine and behavioral responses afterin vivoadministration to the adult male rat. Animals that were administered prepro-TRH178–199 intravenously 5 min before restraint stress exhibited a significant attenuation of stress-induced elevations of ACTH, corticosterone, and prolactin, as compared with controls infused with vehicle, whereas thyroid-stimulating hormone (TSH) secretion was not changed.In behavioral studies of stress responsiveness, either the vehicle or prepro-TRH178–199 was administered intracerebroventricularly (ICV) 5 min before testing. In the open field, prepro-TRH178–199 significantly increased grooming, locomotor activity, rearing, and sniffing behaviors. In the light/dark box, it significantly increased the time animals spent in the light compartment and increased the number of crossings between the light/dark compartments. In the plus maze, the peptide significantly increased the amount of time animals spent in the open arms. The same dose of peptide, administered ICV, had no effect on peripheral hormone release in response to restraint stress. Overall, these results support a role for prepro-TRH178–199 in the inhibition of the neuroendocrine responses to stress at the level of the pituitary and indicate that it has central modulatory influences over stress-related behaviors.
cAMP-Dependent Enhancement of Dihydropyridine-Sensitive Calcium Channel Availability in Hippocampal Neurons
Authors: Kavalali Ege T. , Hwang Katherine S. , Plummer Mark R. 
Published: April 2018

Dihydropyridine-sensitive calcium channels can be strongly modulated by cAMP-dependent phosphorylation. This modulation takes the form of increased channel availability in cardiac myocytes (for review, see McDonald et al., 1994) and has been suggested to be essential for voltage-dependent facilitation in adrenal chromaffin cells (Artalejo et al., 1992) and skeletal muscle (Sculptoreanu et al., 1993b). To determine the role of cAMP-dependent phosphorylation on dihydropyridine-sensitive calcium channels in hippocampal neurons, we have used both single-channel and whole-cell recording techniques and have examined the effects of the membrane-permeable cAMP analog 8-(4-chlorophenylthio) (CPT)-cAMP and the protein kinase inhibitors 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) andN-[2-(p-bromocinnamyl-amino)ethyl]-5-isoquinolinesulfonamide (H-89).Hippocampal neurons contain two kinds of dihydropyridine-sensitive calcium channel activity: Ls and Lp (Kavalali and Plummer, 1994). The Ls channel closely resembles the cardiac L-type channel, whereas the Lp channel shows a novel low-voltage form of voltage-dependent potentiation (Kavalali and Plummer, 1996). 8-CPT-cAMP increased the availability of both the Ls and Lp channels and caused a parallel increase in Lp channel reopenings at the repolarization potential that result from voltage-dependent potentiation. This effect was completely blocked by the broad spectrum kinase inhibitor H-7 and by the protein kinase A-specific inhibitor H-89. The two inhibitors, however, did not disrupt baseline potentiation of the Lp channel, suggesting that cAMP-dependent protein kinase activity can enhance Ls and Lp channel activity but is not required for voltage-dependent potentiation in hippocampal neurons.
Muscarinic Induction of Synchronous Population Activity in the Entorhinal Cortex
Authors: Dickson Clayton T. , Alonso Angel 
Published: April 2018

Oscillation and synchronization of neural activity is important in normal brain function but is also relevant to epileptogenesis. One of the most frequent forms of epilepsy originates in temporal lobe circuitry of which the entorhinal cortex (EC) is crucial. Because muscarinic receptor activation promotes oscillatory dynamics in EC neurons, we investigated in a brain slice preparation the effects of carbachol (CCh) on oscillatory population activity in the EC. We found that CCh produced epileptiform activity in EC, which according to field profile and current source density analysis was usually driven by layer V. In addition, localized CCh application and surgical isolation experiments demonstrated that EC layer II, but not layer III, can also independently generate synchronous population activity.Intracellular recordings from EC principal cells during epileptiform activity demonstrated large-amplitude, synaptically driven depolarizing events and bursts of action potentials synchronized to the field spikes. In layer II neurons, the depolarizing events had a multiphasic reversal potential that suggested concurrent glutamatergic and GABAergic synaptic input. Interestingly, although the epileptiform activity required activation of AMPA but not NMDA receptors, small-amplitude field spikes persisted during block of fast excitatory neurotransmission. These field spikes were correlated to large-amplitude IPSPs in layer II neurons, and both activities were abolished by GABAA-receptor antagonism. Thus, in response to muscarinic activation, pools of EC interneurons discharge synchronously by a mechanism not necessarily involving principal cell activation.Given the differential projection pattern of EC layers V and II toward the neocortex and hippocampus, respectively, their robust epileptogenic character may be of major importance in temporal lobe epilepsy.
An Anatomical Basis for Visual Calibration of the Auditory Space Map in the Barn Owl’s Midbrain
Authors: Feldman Daniel E. , Knudsen Eric I. 
Published: April 2018

The map of auditory space in the external nucleus of the inferior colliculus (ICX) of the barn owl is calibrated by visual experience during development. ICX neurons are tuned for interaural time difference (ITD), the owl’s primary cue for sound source azimuth, and are arranged into a map of ITD. When vision is altered by rearing owls with prismatic spectacles that shift the visual field in azimuth, ITD tuning in the ICX shifts adaptively. In contrast, ITD tuning remains unchanged in the lateral shell of the central nucleus of the inferior colliculus (ICCls), which provides the principal auditory input to the ICX, suggesting that the projection from the ICCls to the ICX is altered by prism-rearing.In this study, the topography of the ICCls–ICX projection was assessed in normal and prism-reared owls by retrograde labeling using biotinylated dextran amine. In juvenile owls at the age before prism attachment, and in normal adults, labeling patterns were consistent with a topographic projection, with each ICX site receiving input from a restricted region of the ICCls with similar ITD tuning. In prism-reared owls, labeling patterns were systematically altered: each ICX site received additional, abnormal input from a region of the ICCls where ITD tuning matched the shifted ITD tuning of the ICX neurons. These results indicate that anatomical reorganization of the ICCls–ICX projection contributes to the visual calibration of the ICX auditory space map.
The effect of exchange transfusion on prooxidant-antioxidant balance in newborns Jaundice
Authors: Boskabadi Hassan , Kalate Mollaei Maryam , Zakerihamidi Maryam , Ghayour Mobarhan Majid , Bagheri Fatemeh 
Published: April 2018

Introduction: Newborns have a limited amount of antioxidant protection. Exchange transfusion may affect Prooxidant-Antioxidant Balance (PAB). The present study is conducted to investigate the effect of the exchange transfusion on PAB in newborn jaundice.
Methods: The present study is based on a clinical trial which is conducted at Ghaem Hospital in Mashhad, Iran during 2015-2016 that involved sampling on 22 jaundiced newborns (high bilirubin of 17 mg/dL) over a course of 35 weeks. Data collection for the study questionnaire included maternal blood group, neonatal characteristics (age, sex, weight, gestational age, Apgar score, etc.), and laboratory assessment (bilirubin, hematocrit, direct and indirect Coombs testing, reticulocytes, Glucose-6-phosphate dehydrogenase (G6PD), thyroxine (T4), thyroid stimulating hormone (TSH), and PAB). The amount of PAB and serum total bilirubin (STB) of newborns before, after and 6 hours after the exchange transfusion were investigated. Data analysis was performed via statistical tests (paired t-test) using SPSS version 19.
Results: The average bilirubin before the exchange transfusion was 22.02±5.80 mg/dL, after the exchange transfusion was 11.56±3.95 mg/dL, and at 6 hours after the exchange transfusion was 14.99±4.20 mg/dL. The average PAB before the exchange transfusion was 19.06±11.91 HK units, after the exchange transfusion was 29.40±17.70 HK, and at 6 hours after the exchange transfusion was 40.82±18.79 HK.
Conclusion: The results of the study show that the Prooxidant-Antioxidant balance in the exchange transfusion changes in favor of prooxidants and also intensifies even up to 6 hours after the exchange transfusion.
Documentation of Sexual History in Hospitalized Adolescents on the General Pediatrics Service
Authors: Riese Alison , Tarr Elizabeth E. , Baird Janette , Alverson Brian 
Published: April 2018

OBJECTIVES:
To determine the frequency of sexual history taking and the associated characteristics of hospitalized adolescents in the pediatric hospitalist service.

METHODS:
A retrospective chart review of adolescents 14 to 18 years old who were admitted to the pediatric hospitalist service at an urban, academic children’s hospital in the Northeast from 2013 to 2015 was conducted. Repeat admissions, admissions to specialty services, and charts that noted impairment because of psychosis, cognitive delay, or illness severity were excluded. For charts that met the criteria, the admission history and physical was carefully reviewed for a notation of sexual history. For those with documentation, sexual activity status and a risk level assessment were recorded. Patient demographics and admission characteristics were extracted. χ2 tests and logistic regression were used to examine differences between those with sexual history and those without.

RESULTS:
A total of 752 charts met the criteria for inclusion. The majority of adolescents were girls (n = 506; 67.3%); the mean age was 15.7 years (SD = 1.2). Girls had 2.99 (95% confidence interval [CI] 2.18–4.11) higher odds of documentation than boys, and older adolescents had 1.41 (95% CI 1.03–1.91) higher odds than younger adolescents. Documentation did not differ significantly on the basis of admission type (medical or psychiatric), admission time, patient race and/or ethnicity, or provider gender. Among those with a documented sexual history, risk-level details were often omitted.

CONCLUSIONS:
Sexual history taking does not occur universally for hospitalized adolescents. Girls were screened more often than boys despite similar rates of sexual activity. The inpatient admission may be a missed opportunity for harm-reduction counseling and adherence to sexually transmitted infection testing guidelines.
A Comparison of Resident Self-Perception and Pediatric Hospitalist Perceptions of the Supervisory Needs of New Interns
Authors: Winn Ariel S. , Marcus Carolyn H. , Sectish Theodore C. , Williams Kathryn , Landrigan Christopher P. 
Published: April 2018

OBJECTIVES:
The Association of American Medical Colleges published a list of entrustable professional activities (EPAs) that graduating medical students should be able to perform on day 1 of residency without direct supervision. We sought to explore the perceptions of residents and pediatric hospitalists about the level of supervision new interns need in conducting these EPAs.

METHODS:
An electronic survey was sent to pediatric hospitalists who supervise interns in a large pediatric residency program in which they were asked to rate the amount of supervision they perceive new interns need when performing 11 EPAs. Another survey was sent to residents in which they were asked how much supervision they needed at the beginning of their intern year when performing the same EPAs. Hospitalist and resident responses were compared.

RESULTS:
The majority of hospitalists thought new interns could perform only 5 of the 11 EPAs without direct supervision. For 5 of the EPAs, residents’ perceptions of their own abilities to perform the EPA independently as interns were significantly greater than the hospitalists’ perceptions of interns’ abilities. For example, 91% of residents thought they were able to recommend and interpret common diagnostic and screening tests when they were interns without direct supervision, compared with only 30% of attending physicians (P &lt; .001).

CONCLUSIONS:
Hospitalists and residents in a pediatric residency training program reported that new interns were not consistently able to perform the Association of American Medical Colleges’ core EPAs without supervision. Furthermore, residents and pediatric hospitalists perceived new interns’ abilities to perform the EPAs without direct supervision significantly differently.
Network Measures of Collaborative Support for Young Adults With Autism
Authors: McGhee Hassrick Elizabeth , Shattuck Paul , Carley Kathleen 
Published: April 2018

OBJECTIVES:The treatment of autism requires complex, multimodal interventions, provided by parents and providers across settings. As young adults with autism spectrum disorder (ASD) transition into adulthood, new stakeholders are added to support planning for postsecondary employment. In this article, we investigate the use of dynamic social network measures that describe the resources of young adults throughout transition.METHODS:A longitudinal, dynamic social network survey (Social Dynamics of Intervention [SoDI]) was conceptualized, designed, and conducted as a feasibility test, measuring changes in collaboration among parents and school staff members who provided interventions for children with ASD in 2 urban public schools. Using the SoDI, we tracked the following over time: the team who provided interventions, their locations, the interventions they provided, the autism trainings they attended, and the density of the team’s problem-solving network for the child.RESULTS:Using the SoDI, we successfully identified stakeholders across settings who provided interventions for each child. Results indicated variation in the density of problem-solving and trust related to ASD intervention across teams as well as variation in intervention and autism knowledge networks during the school year. Adaptations of the SoDI for mapping pre- and posttransition resources and social connectivity across stakeholders for young adults with ASD are proposed in the Discussion section.CONCLUSIONS:Dynamic social network approaches can be used to capture changes in intervention, autism knowledge, and social connectivity, providing informative descriptive data about how vocational rehabilitation policies might increase employment supports during the transition process for young adults with ASD.
Barriers to Receipt of Services for Young Adults With Autism
Authors: Anderson Connie , Lupfer Alexis , Shattuck Paul T. 
Published: April 2018

OBJECTIVES:In this study, we examine experiences of families of young adults (YAs) on the autism spectrum to better understand dynamics leading to poor YA outcomes.METHODS:Twenty parents of YAs with autism spectrum disorder (ASD) who had completed high school in the past 15 years took part in a 90-minute interview. They described their YA’s experiences at the transition from high school and current status with regards to services or postsecondary education. Qualitative interviews were digitally recorded, transcribed, and analyzed by using the constant comparative method associated with a grounded theory approach.RESULTS:Few adults with ASD were receiving autism-specific assistance no matter their level of cognitive functioning. Existing systems, such as service agencies and college disability support offices, had seldom been designed to meet their needs. Some families gave up on services, some used self-directed services they had to manage themselves, and others paid out of pocket for services they could access no other way. Inadequate services often led to YA failure and worsening of symptoms. The majority of families bore the financial and emotional brunt of finding or creating services and community experiences to meet their adult child’s needs.CONCLUSIONS:Parent narratives highlight the difficulties that are faced as families attempt to access appropriate services for YAs on the autism spectrum at all levels of functioning. These insights can help pediatricians understand family concerns and develop anticipatory guidance strategies. More research is needed to identify potential solutions to challenges faced by specific subgroups of YAs with ASD.