bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antinociceptive Effects of Novel GABAA Receptor Positive Allosteric Modulators in Mice: Pain‐Stimulated and Pain‐Depressed Behaviors
Authors: Lewter Lakeisha , Cook James M , Li Jun‐Xu 
Published: November 2023

Preclinical pain and analgesia research has primarily focused on pain‐stimulated behaviors, despite the fact that pain often depresses certain behaviors. Positive allosteric modulators (PAMs) that are selective for α2/α3 subunit‐containing GABAA receptors have been shown to mediate profound analgesia in animal models of inflammatory and neuropathic pain. However, the ability of α2/α3 GABAA receptor PAMs to restore pain‐depressed behaviors have not been explored. This study sought to examine the effects of two novel α2/α3 selective PAMs, KRM‐II‐18B and KRM‐II‐81, on acetic and lactic acid‐induced writhing (pain‐stimulated behavior), and two pain‐depressed behaviors: acid‐induced suppression of locomotor activity and acid‐induced depression of nesting behavior in mice. Drug effects of PAMs were compared with currently available analgesics morphine and acetaminophen. Intraperitoneal (i.p.) administration of acetic acid (0.6%) and lactic acid (0.32%) induced stimulation of writhing, depression of locomotor activity, and depression of nesting behavior. Morphine, KRM‐II‐18B, and KRM‐II‐81 pretreatment all produced dose‐dependent and significant decreases in both acetic acid and lactic acid‐induced writhing. This effect was attenuated by the benzodiazepine receptor antagonist flumazenil, confirming that the analgesic effects of KRM‐II‐18B and KRM‐II‐81 are mediated through the benzodiazepine binding site of GABAA receptors. While pretreatment of acetaminophen was able to block acid‐depressed locomotion, pretreatment of both PAMs failed to block acid‐depressed locomotor activity. In the nesting procedure, morphine, KRM‐II‐18B, and KRM‐II‐81 failed to alleviate acetic acid‐induced depression of nesting behavior, but dose‐dependently attenuated lactic acid‐induced depression of nesting. Taken together, these findings suggest that the ability of subunit‐selective PAMs to alleviate pain‐depressed behavior is moderately assay dependent and also depends on the degree of pain.Support or Funding InformationThis research was supported by RO1DA034806.
Effects of α7 nicotinic receptor positive allosteric modulator on sodium‐potassium‐chloride co‐transporter 1 activation following lipopolysaccharide‐induced neuroinflammatory pain in mice
Authors: Rahman Shafiqur , Abbas Muzaffar 
Published: November 2023

Neuroinflammatory pain is a chronic neurological disorder characterized by allodynia and hyperalgesia. We have shown that 3a,4,5,9b‐tetrahydro‐4‐(1‐naphthalenyl)‐3H‐cyclopentan[c]quinoline‐8‐sulfonamide (TQS), an α7 nicotinic acetylcholine receptors (α7 nAChRs) positive allosteric modulator (PAM), reduces neuroinflammatory pain, and microglial activation in the hippocampus in mice. The objective of the present study was to determine the effects of TQS, and bumetanide (BU), sodium‐potassium‐chloride co‐transporter 1 (NKCC1) antagonist, on lipopolysaccharide (LPS)‐induced neuroinflammatory pain using von Frey hair test, a widely used method for the quantification of tactile allodynia and hot plate test, a widely used technique for thermal hyperalgesia assessment, in male mice. In addition, we examined the effects of TQS (4 mg/kg) on NKCC1 mRNA expression and p‐NKCC1 immunofluorescence in the hippocampus. TQS (4 mg/kg) significantly decreased LPS‐induced tactile allodynia and thermal hyperalgesia. In addition, co‐administration of BU (10 mg/kg) with TQS (1 mg/kg) reduced tactile allodynia and thermal hyperalgesia. Taken together, these results suggest that TQS decreases LPS‐induced neuroinflammatory pain by reducing NKCC1 activation through modulating microglial α7 nAChR allosteric site.Support or Funding InformationSupported by Fulbright Foundation USA
Lasting anti‐hyperalgesic effect of nanoemulsion containing essential oil of H. pectinata in an animal model of fibromyalgia
Authors: Quintans Lucindo Jose , Quinans Jullyana Siqueira , Camargo Zaine , Arrigoni‐Blank Maria F , Brito Renan , Oliveira Marlange , Santos Marcio , Araújo Adriano , Kolker Sandra J , Sluka Kathleen 
Published: November 2023

Hyptis species are aromatic plants that produce essential oils which present pharmacologically active substances with antimicrobial, anti‐HIV, analgesic and antiinflammatory activities. We previously demonstrated the analgesic profile of leaf essential oil of Hyptis pectinata, a medicinal plant widely used in Brazilian folk medicine, however, its pharmacological effect is not durable enough for possible applicability in chronic disorders. Thus, we developed and evaluated a nanoemulsion containing leaf essential oil of H. pectinata (NE‐EOH) produces a long‐lasting anti‐hyperalgesic effect on chronic musculoskeletal pain animal model. The NE‐EOH was prepared by addition of 20 wt% Pluronic F127 and showed hydrodynamic diameter and zeta potentials of 220±28 and 10.1±7.2, respectively. Mice were assessed for mechanical hyperalgesia of the paw and muscle (von Frey and tweezer), motor coordination (Rota Rod) and muscle strength (Grip Strength Meter) beginning 1 h after treatment and continuing through 11 days. NE‐EOH, one single treatment (first day only), produced a significant reduction (p<0.05 or p<0.01) of hyperalgesic behavior. This analgesic activity was reversed by both naloxone and methysergide. Moreover, NE‐EOH reduced (p<0.05) substance P levels in neurons from the spinal cord. Thus, NE‐EOH produced a lasting antihyperalgesic effect probably mediated by brainstem inhibitory pathways or reducing excitatory neurotransmitters in the spinal cord.Support or Funding InformationCNPq/Brazil [Grants # 441969/2014‐3, 200636/2012‐0 and 470774/2011‐8], FAPITEC/SE/Brazil, CAPES/Brazil and FINEP/Brazil.
D‐Limonene complexed with β‐cyclodextrin reduces hyperalgesia in a mice model for fibromyalgia
Authors: Barreto Rosana SS , Lima Pollyana SS , Araujo Heitor G , Pereira Erik WM , Rezende Marilia M , Guimaraes Adriana G , Barreto Andre S , Santos Marcio RV , Araujo Adriano AS , Quintans‐Junior Lucindo J , Quintans Jullyana SS 
Published: November 2023

D‐limonene (LIM) is a monocyclic monoterpene with a lemon‐like odor and is a major constituent in several citrus oils (orange, lemon, mandarin, lime, and grapefruit). The analgesic profile of LIM has been described previously. However, the short half‐life and water insolubility has been a limitation to LIM medicinal uses. So, cyclodextrins, such as β‐cyclodextrin (β‐CD), has been an important tool to minimize these limitations of non‐polar compouns, as LIM. Now, we assessed the anti‐hyperalgesic effect of LIM‐β‐CD complexed or LIM alone in an animal model of chronic musculoskeletal pain. Thus, mice model of musculoskeletal pain was performed as reported by Sluka et al. After we confirmed hyperalgesic behavior, mice were treated with LIM‐β‐CD or LIM (50 mg/kg; p.o.) or vehicle (saline 0.9%, p.o.) or tramadol (TR, 4 mg/kg, i.p.). The mice treated with LIM‐β‐CD showed significant (p<0.001) superior anti‐hyperalgesic effect when compared with LIM alone, these effects can not produced any alteration in the grip strength force. Additionally, we perfused the lumbar spinal cord collected, crioprotected, cut and submitted in an imunofluorescence protocol for Fos protein. Both, LIM‐β‐CD or LIM, significantly (p<0.001) reduced expression of Fos protein on spinal cord horn. Thus, we can suggest that β‐CD improves the anti‐hyperalgesic effect produced by LIM and this effect seems to be due the involvement of descending pain inhibitory mechanisms.Support or Funding InformationCNPq, CAPES, FAPITEC‐SE and FINEP/Brazil
TRPV1 Mediates The Orofacial Antinociceptive Effect of Frutalin: In Vivo and In Silico Studies
Authors: Barros Adriana Rolim Campos , de Barros Mamede Vidal Damasceno Marina , Santos Sacha Aubrey Alves Rodrigues , de Maria de Albuquerque Melo José , Magalhães Francisco Ernani Alves , Vieira‐Neto Antonio Eufrásio , de Azevedo Moreira Renato , de Oliveria Monteiro‐Moreira Ana Cristina 
Published: November 2023

Our previous studies have shown the orofacial antinociceptive effect of frutalin (FTL) and it was suggested that FTL effect on acute orofacial pain could be mediated by TRPA1 and TRPV1. Docking study indicated that FTL strongly interacts with TRPV1. This study was conducted to investigate the relationship between TRPV1/TRPA1 channels and the orofacial antinociceptive effect of FTL. Mice (n=6/group) were pretreated with vehicle (0.9 % NaCl; 10 mL/kg; i.p.), FTL (0.5 mg/kg; i.p.), ruthenium red (TRPV1 antagonist, 3 mg/kg, s.c.) or camphor (TRPA1 antagonist, 7.6 mg/kg, s.c.) 30 min before injection (20 μL) of capsaicin (TRPV1 agonist, 1.6 μg/lip) or cinnamaldehyde (TRPA1 agonist, 13.2 μg/lip). In order to verify the involvement of TRPV1 and TRPA1 channels, others groups of mice were pretreated with the respective antagonist 15 min before administration of FTL. Nociception was quantified as time (s) spent rubbing the site of injection 0–5 min after induction. The interaction between FTL and TRPA1 was analyzed using molecular docking. The HEX software was used for molecular docking calculations and the direct action of FTL on TRPA1 was viewed using PyMOL v1.4.7. Experimental protocols were approved by the UNIFOR Animal Research Ethics Committee (#0122014). Pretreatment with FTL was associated with a reduction in the intensity of face rubbing induced by capsaicin (***p<0.001) or cinnamaldehyde (****p<0.0001). Ruthenium red, but not camphor, abolished the antinociceptive effect of FTL. It was possible to observe a direct action of FTL amino acids (Asp149, Tyr146, Trp 147 and Gly25) on TRPA1 glycosylated amino acids (1.8–3.6 Å). However, out of 10 more energetic clusters, only 4 overlapped, suggesting that there are repulsions and chemical impediments that hinder the FTL fitting more than once in the same site of the channel. The energies observed in the 10 investigated clusters are high, but do not exceed those previously observed for TRPV1 channel. FTL antinociceptive effect was abolished by the TRPV1 antagonist, but not by the TRPA1 antagonist and FTL. Besides this, FTL strongly interacts with TRPV1 and it has a weak interaction with TRPA1. Since and TRPV1 and TRPA1 channels are co‐expressed and they interact in neurons, we suggest that FTL effect is mediated by TRPV1.Support or Funding InformationEdson Queiroz Foundation (FEQ), Cnpq and Capes.
Ca2+ Signaling Inhibitors Attenuate the Antinociceptive but not Discriminative Stimulus Effects of the Imidazoline I2 Receptor Agonist 2‐BFI in Rats
Authors: Siemian Justin Nicholas , Zhang Yanan , Li Jun‐Xu 
Published: November 2023

Recent research has established the imidazoline I2 receptor as a promising target for the development of novel analgesics. However, despite a strong understanding of imidazoline I2 receptor‐mediated behavioral effects, little is known about its post‐receptor signaling mechanisms. This study examined the effects of several inhibitors of Ca2+ signaling mechanisms on two behavioral effects of the prototypical imidazoline I2 ligand 2‐BFI. The von Frey test was used to examine the antinociceptive effects of 2‐BFI in complete Freund's adjuvant (CFA)‐induced inflammatory pain in rats. A two‐lever drug discrimination paradigm in which rats were trained to discriminate 5.6 mg/kg (i.p.) 2‐BFI from saline was used to examine the discriminative stimulus effects of 2‐BFI. The L‐type Ca2+ channel blockers verapamil and nimodipine, the calmodulin antagonist W‐7, and the internal Ca2+ release inhibitor ryanodine dose‐dependently attenuated the antinociceptive effects of 2‐BFI. Oxycodone‐induced antinociception was unaffected by verapamil and nimodipine. In contrast, verapamil, nimodipine, and W‐7 did not affect the discriminative stimulus effects of 2‐BFI. These results suggest that the antinociceptive effects of 2‐BFI involve intracellular Ca2+ elevation and/or downstream Ca2+/calmodulin signaling, whereas the discriminative stimulus effect of 2‐BFI is mediated by a distinct, independent mechanism.Support or Funding InformationR01DA034806
Cocaine as Opposed to Methamphetamine Did not Restore CirWadian Activity Rhythms in Arrhythmic Suprachiasmatic Nucleus Lesioned C3H/HeN Mice when Paired with Running Wheel
Authors: Vega Juliany Yari Marrero , Clough Shannon , Dubocovich Margarita L 
Published: November 2023

The “master biological clock” or suprachiasmatic nucleus (SCN) orchestrates synchrony among central and peripheral circadian oscillators. When the SCN is removed the circadian rhythm of an organism becomes arrhythmic. However, when methamphetamine (Meth), a psychostimulant, is given to mice ad libitium in drinking water, it rescues the locomotor behavioral rhythms in arrhythmic SCN lesioned (SCNX) mice (Tataroglu et al., JBiol Rhythms 2006;21;185–94). We recently demonstrated that Meth, which increases dopamine release by reversing the neuronal transporter, paired with concurrent access to running wheel (RW), is necessary for the expression of circadian entrainment in SCNX mice, possibly by activating an extra‐SCN brain oscillator (Rawashdeh et al. FASEB J, 2016). The goal of our project was to determine the ability of another psychostimulant, cocaine, which increases depolarization‐evoked dopamine release by blocking neuronal uptake, to establish rhythmic circadian activity in SCNX mice. Following the protocol described by Rawashdeh et al., 2016, C3H/HeN male mice (3–4 months old) underwent sham surgery (n=8) or SCN electrolytic lesions (n=11) (SCNX). Sham operated (free running circadian rhythms) and SCNX (arrhythmic) mice in constant dark were given a single daily vehicle (0.9% saline, i.p.) or cocaine (20 mg/kg, i.p.) injection at the beginning of an 8‐hour period of restricted RW access, for 14 days. Mice were then provided a 7‐day period of continuous access to RW to assess the development of a free running circadian activity rhythm. Our results demonstrate that SCNX mice treated for 14 days with either vehicle or cocaine paired with RW did not develop rhythmic circadian activity. This is in contrast to Meth, which when used in the same paradigm, induced a free‐running rhythm in SCNX mice (Rawashdeh et al., 2016). Although both Meth and cocaine, at doses that elicit similar levels of locomotor activity, increase the extracellular concentration of dopamine in the striatum and nucleus accumbens, the net levels of extracellular dopamine are 2–3 times fold higher following treatment with Meth (reversal of dopamine transporter) than with cocaine (blockade of neuronal uptake) (Kuczenski, et al., J Neurosci 1991;11; 2703–12). We suggest that increased level of synaptic dopamine induced by Meth paired with RW compared to cocaine may be necessary to re entrain circadian activity rhythms in arrhythmic mice.Support or Funding InformationSupported by JSMBS funds to MLD
Evaluation of the Anticonvulsant Effects of Propofol in Pentylenetetrazole kindled Rats
Authors: Hasan Zuheir A 
Published: November 2023

Propofol is a short‐acting intravenous anesthetic which is widely for the induction and maintenance of anesthesia. However, sporadic reports on the occurrence of seizures in epileptic and non‐epileptic patients, especially during recovery continue to appear. Experiments on Sprague‐Dawley rats were carried out to study the effects of propofol on clonic‐tonic convulsions in kindling phenomena evoked by multiple injections of a subconvulsive dose (40 mg/kg) pentylenetetrazol (PTZ). Kindling was considered to be completed when an animal had experienced generalized clonic–tonic seizures (stage 5). To induce complete kindling 14.0 ± 1 injections were performed. Once the animals consistently exhibit full stage of kindling, different animal groups were injected intravenously with various doses of propofol (5, 10 and 20 mg/Kg). Following the administration of propofol, kindled rats were injected with 40 mg/Kg PTZ and the seizure score was evaluated. The results of the present study showed that the highest two doses of propofol (20, 0 mg/Kg) prevent the occurrence of any kind of convulsions. The lowest dose (5 mg/Kg) did not significantly reduce the incidents of clonic‐tonic. These data suggest that propofol has marked dose dependent anticonvulsant effects on generalized clonic‐tonic convulsions in PTZ kindled rats and provides further support for the anticonvulsant effects of propofol reported in other experimental seizures models. (Supported by a grant from Arabian Gulf University).Support or Funding InformationArabian Gulf University
ATP Exposure Increases Expression of α‐Synuclein in SH‐SY5Y Cells: Potential Link Between Neuronal Injury and Parkinson's Disease
Authors: Lamberts Jennifer T. , Rustem Danielle , Wallis Brittnie , Zwart Colton 
Published: November 2023

Parkinson's disease (PD) is a devastating neurodegenerative disorder for which there is presently no cure. The pathologic hallmark of PD is intra‐neuronal accumulation of the protein α‐synuclein (α‐syn), and in rare instances, PD has been directly linked to multiplication of the α‐syn gene locus, suggesting that overexpression of α‐syn is pathogenetic per se. It has been suggested that α‐syn aggregation is increased in cells exposed to ATP, a condition known to arise during traumatic brain injury. These results suggest a potential link between neuronal injury, purinergic signaling, and the pathogenesis of PD, yet there remains limited information about this phenomenon. The primary goal of this project was to test the effect of ATP exposure on intracellular expression and extracellular secretion of α‐syn in mammalian cells. In preliminary studies, SH‐SY5Y cells treated for 24h with 1mM or 3mM ATP expressed higher levels of α‐syn protein, as measured by Western blot. However, these concentrations of ATP also slightly reduced cell viability at 24h, as measured by CellTiter‐Blue® assay. These results further support the proposed link between purinergic signaling and PD pathogenesis. These and future studies will provide much needed insight into the role of purinergic signaling in PD and could help identify novel therapeutic targets for the treatment of PD.Support or Funding InformationThis project was funded by an internal Faculty Research Grant from Ferris State University and startup funds from the College of Pharmacy at Ferris State University.
The effect of sex on APOE‐modulated AD pathology in EFAD mice
Authors: Avila‐Munoz Maria Evangelina , Balu Deebika , York Jason , Ghura Shivesh , Collins Nicole , Ladu Mary Jo 
Published: November 2023

APOE4 allele of apolipoprotein E (apoE) is the greatest genetic risk factor for Alzheimer's disease (AD) and is associated with accelerated accumulation of both amyloid plaques and and soluble oligomeric forms of the amyloid‐β peptide (oAβ), likely a proximal neurotoxin. Importantly, female APOE4 carriers have a greater lifetime risk for developing AD, an increased rate of cognitive decline and accelerated accumulation of Aβ compared to male APOE4 carriers. In vivo progress has been limited by the lack of a tractable familial AD‐transgenic (FAD‐Tg) mouse model expressing human (h)‐ rather than mouse (m)‐APOE. To study the interactions among sex, h‐APOE and AD pathology, we developed the EFAD‐Tg mice by introducing the h‐APOE genotypes into the 5×FAD‐Tg mice. We previously demonstrated that in the EFAD mice, confirmed in human control and AD samples of CSF and brain, that apoE lipidation is lower and soluble Aβ levels are higher with APOE4 vs. APOE3. Thus, we have developed the mechanistic hypothesis that AD pathology and APOE4 cause a reduction in apoE lipidation, resulting in inefficient clearance of soluble A β synaptic loss, memory/cognitive deficits, and dementia. Novel preliminary data demonstrate that the differences in female vs. male E4FAD mice mimic these established APOE4 vs. APOE3 differences in Aβ aggregation/accumulation, and apoE levels/lipidation. In addition, amyloid deposition, neuroinflammation and tau pathology is significantly greater in the EFAD females compared to males. These data suggest that sex profoundly influences APOE genotype‐specific effects on AD pathology, with apoE lipidation and oAβ levels possibly at the intersection between these two AD risk factors. Together, these data will help to address the critical need for treatment options for women at high risk for AD from the APOE4 allele.Support or Funding InformationCurrent LaDu lab funding includes NIH (NIA) P01AG044682, R21AG030128, R21AG048498, R21AG051233, CCTS (UL1RR029879)
ApoE Remodeling as a Therapeutic Target for Alzheimer's Disease
Authors: Ladu Mary Jo , Avila‐Munoz Maria Evangelina , Valencia‐Olvera Ana , Ghura Shivesh , Collins Nicole , Balu Deebika , York Jason 
Published: November 2023

APOE4 is the greatest genetic risk factor for Alzheimer's disease (AD), increasing risk up to 15‐fold compared to APOE3. As ɛ4 carriers can respond anomalously in clinical trials, there is a critical lack of therapeutics targeting mechanistic pathways of APOE4‐induced AD risk. APOE4 is associated with accelerated amyloid‐β (Aβ) accumulation, both as amyloid and soluble oligomeric forms of Aβ (oAβ), the latter considered a proximal neurotoxin. Using EFAD mice, a new tractable preclinical mouse model (expressing 5 familial AD (FAD) mutations and the human APOE genotypes), we have developed the mechanistic hypothesis that apoE4 is poorly lipidated compared to apoE3, resulting in lower levels of apoE/Aβ complex and higher levels of soluble oAβ. ABCA1 is a promising therapeutic target for testing this hypothesis, as it is a major transporter of lipid to nascent apoE‐containing lipoproteins in the CNS. We previously demonstrated that treatment with RXR agonists increased ABCA1 levels, apoE4 lipidation, and soluble apoE4/Aβ complex levels, while lowering soluble Aβ levels. However, while these data provide target validation for ABCA1, the detrimental effects on the liver limit RXR agonist utility in even short‐term treatment protocols. Therefore, we have identified and are evaluating alternative pharmacological approaches to enhance apoE lipidation, modeling our approach on the peripheral targets for lipoprotein biogenesis and remodeling common in the cardio‐vascular field. Two therapeutic approaches of particular interest are an ABCA1 agonist (Compound A) and an Acyl‐CoA:cholesterol acyltransferase (ACAT) inhibitor (Compound B) to increase cholesterol efflux and free cholesterol availability, respectively. In vitro, both compounds facilitated cholesterol efflux from primary glia and increased the concentration and lipidation of apoE. In vivo, both compounds are brain penetrant and further analysis is on going, including treatment and prevention paradigms with read‐outs that include biochemical and AD pathology, as well as behavioral measurements.Support or Funding InformationP01AG044682, R21AG030128, R21AG048498, R21AG051233, CCTS (UL1RR029879)