Number Of Immunoreactive Cells Research Articles

Oxytocin shortens spreading depolarization-induced periorbital allodynia

BackgroundMigraine is among the most prevalent and burdensome neurological disorders in the United States based on disability-adjusted life years. Cortical spreading depolarization (SD) is the most likely electrophysiological cause of migraine aura and may be linked to trigeminal nociception. We previously demonstrated, using a minimally invasive optogenetic approach of SD induction (opto-SD), that opto-SD triggers acute periorbital mechanical allodynia that is reversed by 5HT1B/1D receptor agonists, supporting SD-induced activation of migraine-relevant trigeminal pain pathways in mice. Recent data highlight hypothalamic neural circuits in migraine, and SD may activate hypothalamic neurons. Furthermore, neuroanatomical, electrophysiological, and behavioral data suggest a homeostatic analgesic function of hypothalamic neuropeptide hormone, oxytocin. We, therefore, examined the role of hypothalamic paraventricular nucleus (PVN) and oxytocinergic (OXT) signaling in opto-SD-induced trigeminal pain behavior.MethodsWe induced a single opto-SD in adult male and female Thy1-ChR2-YFP transgenic mice and quantified fos immunolabeling in the PVN and supraoptic nucleus (SON) compared with sham controls. Oxytocin expression was also measured in fos-positive neurons in the PVN. Periorbital mechanical allodynia was tested after treatment with selective OXT receptor antagonist L-368,899 (5 to 25 mg/kg i.p.) or vehicle at 1, 2, and 4 h after opto-SD or sham stimulation using von Frey monofilaments.ResultsOpto-SD significantly increased the number of fos immunoreactive cells in the PVN and SON as compared to sham stimulation (p < 0.001, p = 0.018, respectively). A subpopulation of fos-positive neurons also stained positive for oxytocin. Opto-SD evoked periorbital mechanical allodynia 1 h after SD (p = 0.001 vs. sham), which recovered quickly within 2 h (p = 0.638). OXT receptor antagonist L-368,899 dose-dependently prolonged SD-induced periorbital allodynia (p < 0.001). L-368,899 did not affect mechanical thresholds in the absence of opto-SD.ConclusionsThese data support an SD-induced activation of PVN neurons and a role for endogenous OXT in alleviating acute SD-induced trigeminal allodynia by shortening its duration.

Negative allosteric modulation of CB1 cannabinoid receptor signaling suppresses opioid-mediated tolerance and withdrawal without blocking opioid antinociception

The direct blockade of CB1 cannabinoid receptors produces therapeutic effects as well as adverse side-effects that limit their clinical potential. CB1 negative allosteric modulators (NAMs) represent an indirect approach to decrease the affinity and/or efficacy of orthosteric cannabinoid ligands or endocannabinoids at CB1. We recently reported that GAT358, a CB1-NAM, blocked opioid-induced mesocorticolimbic dopamine release and reward via a CB1-allosteric mechanism of action. Whether a CB1-NAM dampens opioid-mediated therapeutic effects such as analgesia or alters other unwanted opioid side-effects remain unknown. Here, we characterized the effects of GAT358 on nociceptive behaviors in the presence and absence of morphine in male rats. We examined the impact of GAT358 on formalin-evoked pain behavior and Fos protein expression, a marker of neuronal activation, in the lumbar spinal cord. We also assessed the impact of GAT358 on morphine-induced slowing of colonic transit, tolerance, and withdrawal behaviors in male mice. GAT358 attenuated morphine antinociceptive tolerance without blocking acute antinociception and reduced morphine-induced slowing of colonic motility without impacting fecal boli production. GAT358 also produced antinociception in the presence and absence of morphine in the formalin model of inflammatory nociception and reduced the number of formalin-evoked Fos protein-like immunoreactive cells in the lumbar spinal cord. Finally, GAT358 mitigated the somatic signs of naloxone-precipitated, but not spontaneous, opioid withdrawal following chronic morphine dosing. Our results support the therapeutic potential of CB1-NAMs as novel drug candidates aimed at preserving opioid-mediated analgesia while preventing their unwanted side-effects. Our studies also uncover previously unrecognized antinociceptive properties associated with an arrestin-biased CB1-NAM.

Ovariectomy Increases Blood Pressure and FosB Staining in the Central Autonomic Control Regions Independent of Chronic Intermittent Hypoxia

Chronic intermittent hypoxia (CIH) experimentally mimics the recurrent hypoxia characteristic of sleep apnea, and it induces sustained hypertension in male and ovariectomized (OVX) female rats but not intact females. While central autonomic control regions are known to mediate CIH-induced hypertension in males, their contribution to CIH hypertension in OVX females remains unclear. We tested the hypothesis that 7 days of CIH increases mean arterial pressure (MAP) and FosB staining in central autonomic regions in OVX but not intact female rats. Adult female Sprague Dawley gonadally intact (INT) or OVX rats were exposed to 7 days of CIH (10% O2 and 21% O2 cycle, every 6 mins, 8h/day) or continuous normoxia (CON). MAP was monitored by radiotelemetry. On day 8, the rats were sacrificed, and their brains were collected and processed for FosB immunohistochemistry. During the light/sleep phase, CIH increased MAP in INT females (n=7; 3.4 ± 0.4 mmHg) as compared to CON (n=6, ΔMAP 1.4 ± 0.3 mmHg; P=0.01 CON vs CIH). This difference was not observed during the dark/active phase (CON ΔMAP -1.7 ± 0.4 mmHg, CIH 0.5 ± 0.3 mmHg, P=0.07). In OVX females, CIH was not associated with significant increases in MAP during the light/sleep phase (CON (n=6) ΔMAP 0.3 ± 0.4 mmHg, CIH (n = 6) 2.1 ± 0.3 mmHg, P=0.10). During the dark phase, MAP was significantly increased in CON OVX and CIH OVX compared to their respective baselines but there were no differences between groups (CON ΔMAP 2.4 ± 0.3 mmHg, CIH 2.2 ± 0.4 mmHg, P=0.0002 vs baseline, P=0.8 CON vs CIH). OVX rats had higher baseline FosB staining in the median preoptic nucleus compared to intact female rats independent of CIH exposure (INT: CON (n = 6) 13 ± 3 cells/section, CIH (n = 6) 14 ± 2; OVX: CON (n = 6) 21 ± 3, CIH (n = 6) 23 ± 2, INT CON vs OVX CON, P &lt; 0.05, INT CIH vs OVX CIH P &lt; 0.05). Compared to CON, CIH significantly increased the number of FosB immunoreactive cells in the caudal nucleus of the solitary tract in INT but not OVX females (INT: CON, 7 ± 1 cells/section, CIH 11 ± 1; OVX CON 6 ± 1, CIH n=6, 9 ± 1; INT CON vs CIH, P=0.02; OVX CON vs CIH, P = 0.09). In the rostral ventrolateral medulla, there were no significant differences among any of the groups (INT: CON n=4, 19 ± 2 cells/section, CIH n=4, 20 ± 3; OVX: CON n=6, 18 ± 2, CIH n=6, 21 ± 2, all P&gt;0.05). In OVX females, CIH tended to increase MAP during both the light and dark phases. CON OVX females showed a trend for increased MAP during the dark phase, independent of CIH. CIH was not associated with increased FosB staining in either the median preoptic nucleus or the rostral ventrolateral medulla of OVX females This suggests that changes in MAP observed in CIH OVX females may not involve the same autonomic control regions as male rats exposed to CIH. Supported by RO1 HL155977. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Progesterone distribution in the trigeminal system and its role to modulate sensory neurotransmission: influence of sex

BackgroundWomen are disproportionately affected by migraine, representing up to 75% of all migraine cases. This discrepancy has been proposed to be influenced by differences in hormone levels between the sexes. One such hormone is progesterone. Calcitonin gene-related peptide (CGRP) system is an important factor in migraine pathophysiology and could be influenced by circulating hormones. The purpose of this study was to investigate the distribution of progesterone and its receptor (PR) in the trigeminovascular system, and to examine the role of progesterone to modulate sensory neurotransmission.MethodsTrigeminal ganglion (TG), hypothalamus, dura mater, and the basilar artery from male and female rats were carefully dissected. Expression of progesterone and PR proteins, and mRNA levels from TG and hypothalamus were analyzed by immunohistochemistry and real-time quantitative PCR. CGRP release from TG and dura mater were measured using an enzyme-linked immunosorbent assay. In addition, the vasomotor effect of progesterone on male and female basilar artery segments was investigated with myography.ResultsProgesterone and progesterone receptor -A (PR-A) immunoreactivity were found in TG. Progesterone was located predominantly in cell membranes and in Aδ-fibers, and PR-A was found in neuronal cytoplasm and nucleus, and in satellite glial cells. The number of positive progesterone immunoreactive cells in the TG was higher in female compared to male rats. The PR mRNA was expressed in both hypothalamus and TG; however, the PR expression level was significantly higher in the hypothalamus. Progesterone did not induce a significant change neither in basal level nor upon stimulated release of CGRP from dura mater or TG in male or female rats when compared to the vehicle control. However, pre-treated with 10 µM progesterone weakly enhanced capsaicin induced CGRP release observed in the dura mater of male rats. Similarly, in male basilar arteries, progesterone significantly amplified the dilation in response to capsaicin.ConclusionsIn conclusion, these results highlight the potential for progesterone to modulate sensory neurotransmission and vascular responses in a complex manner, with effects varying by sex, tissue type, and the nature of the stimulus. Further investigations are needed to elucidate the underlying mechanisms and physiological implications of these findings.Graphical

Dietary wheat gluten induces astro- and microgliosis in the hypothalamus of male mice.

Gluten, which is found in cereals such as wheat, rye and barley, makes up a major dietary component in most western nations, and has been shown to promote body mass gain and peripheral inflammation in mice. In the current study, we investigated the impact of gluten on central inflammation that is typically associated with diet-induced obesity. While we found no effect of gluten when added to a low-fat diet (LFD), male mice fed high fat diet (HFD) enriched with gluten increased body mass and adiposity compared with mice fed HFD without gluten. We furthermore found that gluten, when added to the LFD, increases circulating C-reactive protein levels. Gluten regardless of whether it was added to LFD or HFD led to a profound increase in the number of microglia and astrocytes in the arcuate nucleus of the hypothalamus, as detected by immunohistochemistry for ionised calcium binding adaptor molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP), respectively. In mice fed LFD, gluten mimicked the immunogenic effects of HFD exposure and when added to HFD led to a further increase in the number of immunoreactive cells. Taken together, our results confirm a moderate obesogenic effect of gluten when fed to mice exposed to HFD and for the first-time report gluten-induced astro- and microgliosis suggesting the development of hypothalamic injury in rodents.

Immunolocalization of the AT-1R Ang II Receptor in Human Kidney Cancer.

This study aimed to evaluate AT1-R expression in normal and cancerous human kidneys, how these expressions are modified, and AT1-R functionality. AT-1R mRNA expression, determined by real-time PCR, was detected in all samples. AT-1R mRNA increased in well-differentiated cancer (G1, p < 0.01) and decreased 2.9-fold in undifferentiated cancer (G4, p < 0.001) compared with normal kidney tissues. Immunocytochemistry analysis showed that the AT-1R was expressed in the normal tubular epithelium. The glomerulus was also immunoreactive, and as expected, the smooth muscle cells of the vessel walls also expressed the receptor. A total of 35 out of 42 tumors were AT-1R positive, with the cell tumors showing varying numbers of immunoreactive cells, which were stained in a diffuse cytoplasmic and membranous pattern. Computer-assisted counting of the stained tumor cells showed that the number of AT-1R-positive cells increased in the well-differentiated cancers. The functionality of AT-1R was assessed in primary cultures of kidney epithelial cells obtained from three G3 kidney cancer tissues and corresponding histologically proven non-malignant tissue adjacent to the tumor. Indeed, Ang II stimulated, in a dose-dependent manner, the 24 h proliferation of normal kidney cells and cancer cells in the primary culture and phosphorylated extracellular regulated kinases 1 and 2. In conclusion, Ang II may be involved in the growth or function of neoplastic kidney tissue.

Intranasal erythropoietin protects granular cells and reduces astrogliosis in the dentate gyrus after ischemic damage, an effect associated with molecular changes in erythropoietin and its receptor

Within the hippocampus, the CA1 and dentate gyrus (DG) regions are considered the most and the least susceptible to damage by cerebral ischemia, respectively. In addition, it has been tested that rHuEPO exhibits neuroprotective properties. This work investigates the effect of different intranasal doses of rHuEPO, applied in different ischemic post-damage times in the DG, and the effect of the rHuEPO on astroglial reactivity after cerebral ischemia. Additionally, an effective dose for neuroprotection and an administration time was used to evaluate gene and protein expression changes of EPO and EPOR in the DG region. We observed a considerable loss of cells on the granular layer and an increased number of GFAP immunoreactive cells in this region only 72 h after the onset of ischemia/damage. When rHuEPO was administered, the number of morphologically abnormal cells and immunoreactivity decreased. In the analysis of protein and gene expression, there is no correlation between expression level of these molecules, although the rHuEPO amplifies the response to ischemia of EPO and EPOR gene for each evaluated time; in the case of the protein only at 2 h this effect was observed. We demonstrated the susceptibility of the DG to ischemia; so granular cells damage was observed, moreover of the astrocytic response, which is accompanied by molecular changes in signaling mediated by rHuEPO intranasal administration.

The ghrelin agonist, HM01 activates central vagal and enteric cholinergic neurons and reverses gastric inflammatory and ileus responses in rats.

Electrical vagal stimulation alleviates abdominal surgery (AS)-induced intestinal inflammation. Ghrelin receptors (GHS-Rs) are expressed in the brain and peripheral tissues. We investigated the influence of HM01, an orally active ghrelin agonist crossing the blood-brain barrier, on AS-induced gastric inflammation and emptying (GE) in rats. HM01 (6mg/kg) or saline pretreatment was administered per orally (po) or intraperitoneally (ip). We assessed GE, gastric cytokine mRNA, and Fos positive cells in the dorsal motor nucleus of the vagus (DMN) and gastric corpus myenteric plexus (MP) in sham (anesthesia alone) and AS groups. The transcripts of GHS-R1 variants were determined in the medulla oblongata and gastric corpus of naïve rats. In vehicle pretreated rats, HM01 (ip) significantly increased the number of Fos immunoreactive cells in the MP and DMN in 55% and 52% of cholinergic neurons respectively. Hexamethonium did not modify HM01-induced Fos expression in the DMN while reducing it in the MP by 2-fold with values still significantly higher than that in control groups. AS upregulated gastric IL-1β and TNFα expression and inhibited GE by 66.6%. HM01 (po) abolished AS-induced gastric ileus and increased cytokine expression and elevated IL-10 by 4.0-fold versus vehicle/sham. GHS-R1a mRNA level was 5.4-fold higher than the truncated GHS-R1b isoform in the brain medulla and 40-fold higher in the gastric submucosa/muscle layers than in the mucosa. Peripheral HM0 activates central vagal and myenteric cholinergic pathways that may influence both central and peripheral targets to prevent AS-induced gastric inflammatory and ileus.

Comparative effects of curcumin versus nano-curcumin on histological, immunohistochemical expression, histomorphometric, and biochemical changes to pancreatic beta cells and lipid profile of streptozocin induced diabetes in male Sprague–Dawley rats

Diabetes mellitus is a worldwide problem characterized by hyperglycemia as well as the damage of the microscopic structure of the beta cells of Langerhans pancreatic islets. In the present study, the histological, immunohistochemical, morphometric, and biochemical alterations to pancreatic beta cells in streptozocin (STZ)-induced diabetes were assessed in rats treated with curcumin (CU) (100 mg/kg/day) or nano-curcumin (nCU) (100 mg/kg/day) for 1 month. Twenty-four adult male Wistar albino rats were distributed into four groups: the nondiabetic control group, the diabetic untreated group, and two diabetic groups treated with CU or nCUR, respectively. Blood glucose, serum insulin levels, and lipid profile were measured. The pancreatic tissues were collected and processed into paraffin sections for histological and immunohistochemical examination, oxidative stress markers, and real-time PCR expression for pancreatic and duodenal homeobox 1 (PDX1). The insulin expression in beta cells was assessed using immunohistochemistry. Morphometrically, the percentage area of anti-insulin antibody reaction and the percentage area of islet cells were determined. STZ-induced deteriorating alteration in beta cells led to declines in the number of functioning beta cells and insulin immunoreactivity. In STZ-treated rats, CU and nCUR significantly reduced blood glucose concentration while increasing blood insulin level. It also caused a significant increase in the number of immunoreactive beta cells to the insulin expression and significant reduction of the immunoreactive beta cells to the caspase-3 expression. In conclusion, CU and nCUR could have a therapeutic role in the biochemical and microscopic changes in pancreatic beta cells in diabetes-induced rats through STZ administration with more bio-efficacy of nCUR.

Assessment of the neuroprotective effect of selenium-loaded chitosan nanoparticles against silver nanoparticles-induced toxicity in rats

BackgroundWith the recent growth in the applications of silver nanoparticles (Ag-NPs), worries about their harmful effects are increasing. Selenium plays a vital role in the antioxidant defense system as well as free radical scavenging activity. ObjectivesThis study aims to inspect the neuroprotective effect of selenium-loaded chitosan nanoparticles (CS-SeNPs) against the adverse impact of Ag-NPs on brain tissue in adult rats. DesignRats were divided into four groups: group I (control) was administered distilled water (0.5 mL/kg), group II was administered Ag-NPs (100 mg/kg), group III was administered Ag-NPs (100 mg/kg) and CS- SeNPs (0.5 mg/kg) and group IV received only CS- SeNPs (0.5 mg/kg) daily by oral gavage. After 60 days, rats were subjected to behavioral assessment and then euthanized. Brain tissues were obtained for estimation of total antioxidant capacity (TAC), malondialdehyde (MDA), 8-hydroxy-2-deoxy Guanosine (8-OHdG), and Nuclear Factor Erythroid 2 Like Protein 2 (Nrf2). Also, histological examination of the brain and immunohistochemical detection of glial fibrillary acidic protein (GFAP) were investigated Resultsexposure to Ag-NPs induced marked neurotoxicity in the brain tissue of rats that was manifested by decreased levels of TAC and Nrf2 with increased levels of MDA and 8-OHdG. Also, various pathological lesions with an increase in the number of GFAP immunoreactive cells were detected. While brain tissue of rats received Ag-NPs plus CS-SeNPs group (III) revealed significantly fewer pathological changes. ConclusionCo-administration of CS-SeNPs significantly ameliorates most of the Ag-NPs-induced brain damage.

Silymarin attenuates escitalopram (cipralex) induced pancreatic injury in adult male albino rats: a biochemical, histological, and immunohistochemical approach.

Depression is a prevalent global problem since ages, predominately treated with SSRI. Cipralex, is an antidepressant of the SSRIs class used as a remedy for mood, depression and anxiety. Silymarin (SIL), a natural free radical scavenging, has an antioxidant and anti-inflammatory properties. This hypothesis evaluates, for the first time, the role of cipralex on the structure of the endocrine and exocrine components of the pancreas and assess the beneficial effects of SIL on these changes. Forty-five rats were divided into control, cipralex, and cipralex plus SIL groups. During sacrifice, all rats and pancreases were weighed and the ratio of pancreatic weight (PW) to rat weight (RW) was calculated, blood samples were collected to estimate fasting glucose, insulin and amylase levels, the specimens were prepared for histological, immunohistochemical (inducible nitric oxide synthase [iNOS], tumour necrosis factor-alpha [TNF-α], caspase 3, proliferating cell nuclear antigen [PCNA], and anti-insulin antibody), and morphometrical studies. Cipralex group exhibited marked destruction of the pancreatic architecture of the exocrine and endocrine parts, with a dense collagen fiber deposition. Also, there is highly significant decrease (P<0.001) of PW/RT ratio, insulin, and amylase levels, the number and diameter of islets of Langerhans, the number of PCNA positive immunoreactive cells, and the number of insulin positive β-cells. Furthermore, a highly significant increase of glucose level, iNOS, TNF-α, and caspase-3 positive immunoreactive cells in the islets of Langerhans and acinar cells were observed. SIL improves the pancreatic histological architecture, weight loss, biochemical, and immunohistochemical analyses. Administering SIL is advantageous in managing cipralex induced pancreatic injury via its anti-inflammatory, antioxidant, and anti-apoptotic qualities.

Assessment of the anti-nociceptive effects of fetal ventral mesencephalic tissue allografts in a rat model of hemi-Parkinson's disease using fMRI.

Extensive studies showed increased subjective pain sensitivity in Parkinson's disease (PD), which appeared to be partially reversed by dopaminergic (DA) treatment. Although cell replacement represents an attractive therapeutic strategy, its potential for PD-related hyperalgesia remains unclear. We investigated re-establishment of DA function via allografting exogenic DA cells on pain hypersensitivity in a rat model of PD. We evaluated the anti-nociceptive effects of fetal ventral mesencephalic (rVM) tissue allografts in PD rats after unilateral 6-OHDA-induced toxicity in the medial forebrain bundle. The drug -induced rotation test was used to validate the severity of the nigrostriatal lesion; von Frey and thermal pain tests were employed to evaluate nociceptive function. Nociception-induced cerebral blood volume (CBV) response was measured using a 4.7-T MR system. Finally, the immunohistochemical (IHC) studies were performed and the results were compared with the imaging findings from functional magnetic resonance imaging (fMRI). The grafts significantly improved drug-induced rotation behavior and increased mechanical and thermal nociceptive thresholds in PD rats. The elevation of CBV signals significantly recovered on the grafted striatum, whereas this effect was inhibited by the D2R antagonist eticlopride in each striatum. Quantitative IHC analysis revealed the transplantation markedly increased the numbers of tyrosine hydroxylase immunoreactive cells. Therefore, we concluded transplantation of rVM tissue results in anti-nociceptive effects and improves motor function. Moreover, in vivo CBV response confirmed the key role of D2R-mediated pain modulation. Therefore, we demonstrate fMRI as a reliable imaging index in evaluating the anti-nociceptive therapeutic effects of fetal rVM transplantation in the rat model of PD.

Acupuncture Inhibits Morphine Induced-Immune Suppress via Antioxidant System.

Objectives A powerful analgesic called Morphine causes addiction behaviors and immune suppression as a potential oxidative stressor. Acupuncture showed to inhibit oxidative stress-induced hepatic damage, regulate reactive oxygen species, and attenuate morphine addiction behaviors. Therefore, we investigated the potential effects of acupuncture on morphine-induced immune suppression. Materials and Methods Rats received morphine intravenously through implanted catheters for 3, 7, or 21 days to determine the optimal condition for morphine-induced immune suppression. Second, we examined whether intravenous (iv.) or intraperitoneal (ip.) administration produced different results. Third, the effects of acupuncture in rats who received morphine for 21 days were investigated. Spleen and submandibular lymph node (S-LN) weights and natural killer (NK) cell activity were measured, and the white pulp diameter, total and cortical spleen thicknesses, and the number of lymphoid follicles in S-LNs were examined. The number of immunoreactive cells was also measured. Results Decreased organ weights and increased atrophic changes were observed as morphine-induced immune suppression. However, dose-dependent increased immune suppression was not observed between 5.0 mg/kg and 10.0 mg/kg of morphine. And, 3-day withdrawal did not affect. Similar histopathological findings were observed in 5.0 and 10.0 ip. rats when compared to equal dosages of iv., respectively. The morphine induced-immune suppression evidenced by spleen and left S-LN weights, splenic NK cell activities, histopathological findings, and the immunoreactive cell number were normalized by acupuncture. Conclusion These results indicate that acupuncture inhibits morphine-induced immune suppression, maybe via antioxidative action.

Exposure to environmentally relevant doses of plasticizers alters maternal behavior and related neuroendocrine processes in primiparous and multiparous female mice

Phthalates are organic pollutants frequently detected in the environment. The effects of these substances on male reproduction have been extensively studied but their potential impact on female reproductive behaviors in particular at environmental doses still remains to be documented. In the present study, we examined the effects of chronic exposure to di (2-ethylhexyl) phthalate (DEHP) alone at 5 or 50 μg/kg/d, or in an environmental phthalate mixture on maternal behavior of lactating female mice after a first (primiparous) and a second gestation (multiparous). Exposure of DEHP alone or in a phthalate mixture reduced pup-directed behaviors, increased self-care and forced nursing behaviors and altered nest quality for both primiparous and multiparous dams. In pup-retrieval test, primiparous and multiparous dams exposed to DEHP alone or in a phthalate mixture retrieved their pups more rapidly, probably due to a higher emission of ultrasonic vocalizations by the pups. At lactational day 2 following the third and last gestational period, the neural circuitry of maternal behavior was analyzed. A lower number of oxytocin-immunoreactive neurons in the paraventricular and anterior commissural nuclei was found in dams exposed to DEHP alone or in a phthalate mixture, while no changes were observed in the number of arginine-vasopressin immunoreactive cells. In the medial preoptic area, exposure to DEHP alone or in a phthalate mixture reduced ERα-immunoreactive cell number. Dendritic spine density assessed for DEHP at 5 μg/kg/d was also reduced. Thus, exposure to DEHP alone or in a phthalate mixture altered maternal behavior probably through a neuroendocrine mode of action involving oxytocin and estrogen through ERα, key pathways necessary for neuroplasticity and behavioral processing.

Involvement of neurokinin-1 receptors in the autonomic nervous system in colorectal distension-induced cardiovascular suppression in rats.

Situational syncope, which includes rectally mediated reflexes, is defined as syncope induced by a specific situation. Its pathogenesis generally involves disorders of the autonomic nervous system. However, the mechanisms and preventive strategies are not yet well understood. Therefore, we hypothesized that a tachykinin neurokinin-1 receptor might be involved in the autonomic nervous system, and that a neurokinin-1 receptor antagonist could mitigate reflex syncope. This study used a rat model in which the reflex was induced by afferent vagal stimulation with colorectal distension (CRD). In the study, the rats were divided into three groups: non-CRD, CRD, and CRD with a neurokinin-1 receptor antagonist. First, we examined the effect of fosaprepitant, a neurokinin-1 receptor antagonist, on the circulatory response in this model. We then determined the brain regions that showed increased numbers of c-Fos immunoreactive cells in the respective groups. Our results suggest that the colorectal distension procedure reduced blood pressure and that fosaprepitant lowered this response. In addition, the number of c-Fos immunoreactive cells was increased in the caudal ventrolateral medullary region with colorectal distension, and this number was decreased by the administration of fosaprepitant. In conclusion, fosaprepitant might be involved in the vagal reflex pathway and potentially suppress the circulatory response to colorectal distension.

Evaluation of the therapeutic role of allopurinol on bisphenol S gastric and renal toxicity in adult male albino rats: An in vivo study.

Bisphenol S (BPS) is used as an alternative to bisphenol A (BPA) in polycarbonate plastics, epoxy resins and thermal receipt sheet manufacturing. We examined the toxic effects of BPS on gastric and renal functions, as well as the efficacy of allopurinol as a treatment. Albino rats were given only BPS (30 and 120 mg/kg BW/day), and some were treated with allopurinol prior to sacrifice. Gastric and renal specimens were evaluated histologically and immunohistochemically, and blood from the tail vein was analysed for levels of gastrin, uric acid (UA), erythropoietin and 8-deoxyguanosine (8-OHdG). Gastrin levels decreased while erythropoietin, UA and 8-OHdG levels increased significantly. The severity of gastric and renal damage observed in BPS-treated animals increased with increasing doses. The mean percentage of COX-2 immunoreactivity and the mean number of CD45 immunoreactive cells were significantly increased in the stomach and kidney of BPS rats. Allopurinol ameliorated the biochemical, histological and immunohistochemical alterations induced by BPS, with superior protection at lower doses. Allopurinol can reverse the effects of BPS on the stomach and kidneys.

Seasonal Differences in Expression of Neuropeptide Y (NPY) in Visual Centers of Spotted Munia (Lonchura punctulata)

The visual perception of birds is an incredibly exciting subject of research. Birds have significantly higher visual acuity than most other animals, which helps them stay safe in flight and detect their prey. Understanding how the eyes send information to the brain for additional processing is crucial. The brain has sections (nuclei) that accept input from the retina. The key areas where information is processed are the hyperpallium apicale (HA), hippocampus (HP), optic tectum (TeO), nucleus rotundus (RoT), and the geniculatus lateralis ventralis (Glv); among these, the RoT is one of the most investigated nuclei for vision. This study looked at how the visual centers of non-photoperiodic songbirds (Spotted Munia) adapt in different life history stages by looking at NPY expression. We immunohistochemically quantified NPY expression in four different seasons, including pre-breeding (June), breeding (September), post-breeding (December), and regressed (March) in the brain of Spotted Munia. We evaluated changes in the expression levels of the peptide throughout the year, by determining the expression at four different periods throughout the year. Peptide expression levels were projected to fluctuate within photoperiod-induced seasons. It was discovered that the parts of the brain related to vision (RoT, HA, and HP) have a higher number of immunoreactive cells during their mating season, i.e., during the summer. The appearance of NPY, a non-photic marker, in brain areas linked with light perception, was fascinating. Indirectly, NPY aids avian reproduction in a variety of ways. These findings demonstrate the importance of these nuclei in the process of reproduction, as well as the involvement of NPY in the visual brain areas of Spotted Munia.

Glycosaminoglycan, Antimicrobial Defence Molecule and Cytokine Appearance in Tracheal Hyaline Cartilage of Healthy Humans.

Hyaline cartilage is an important tracheal structure, yet little is known about its molecular composition, complicating investigation of pathologies and replacement options. Our aim was to research tracheal hyaline cartilage structure, protective tissue factors and variations in healthy humans. The tissue material was obtained from 10 cadavers obtained from the Riga Stradins University Institute of Anatomy and Anthropology archive. Tissues were stained with Bismarck brown and PAS for glycosaminoglycans, and immunohistochemistry was performed for HBD-2, HBD-3, HBD-4, IL-10 and LL-37. The slides were inspected by light microscopy and Spearman’s rank correlation coefficient was calculated. The extracellular matrix was positive across hyaline cartilage for PAS, yet Bismarck brown marked positive proliferation and growth zones. Numerous positive cells for both factors were found in all zones. All of the antimicrobial defence molecules and cytokines were found in a moderate number of cells, except in the mature cell zone with few positive cells. Spearman’s rank correlation coefficient revealed strong and moderate correlations between studied factors. Hyaline cartilage is a tracheal defence structure with a moderate number of antimicrobial defence protein and cytokine immunoreactive cells as well as numerous glycosaminoglycan positive cells. The extracellular matrix glycosaminoglycans provide structural scaffolding and intercellular signalling. The correlations between the studied factors confirm the synergistic activity of them.

Abstract 3887: β3-adrenergic receptor sustains IFN-γ-dependent PD-L1 expression and impairs anti-tumor immunity in neuroblastoma

Abstract In this study we aimed to investigate the role of the β3-adrenergic receptor (β3-AR) in regulating the immune system response against neuroblastoma (NB) tumor. NB is a very heterogeneous extracranial tumor occurring in childhood. A distinctive feature of NB tumors is their neuroendocrine ability to secrete catecholamines, which in turn, via β-adrenergic receptors ligation, may affect different signaling pathways in the tumor microenvironment (TME). We previously demonstrated that the specific antagonism of the β3-AR on NB tumor cells affected tumor growth and progression. Here, in a murine syngeneic model of NB (A/J mice inoculated with the murine neuroblastoma cell line Neuro-2a), the β3-AR blockade ability to influence the number of immunoreactive and/or immunosuppressive cells in TME was investigated through flow cytometry analysis. Moreover, the involvement of the immune-checkpoint signaling axis PD-1/PD-L1 in mediating the anti-tumoral effects brought by a β3-AR antagonist administration was analyzed. Results demonstrated that β3-AR antagonism leads to an immune response reactivation, partially dependent on the PD-1/PD-L1 signaling axis involvement. Indeed, β3-AR antagonism was able to increase the number of immune reactive CD8+, natural killer (NK) and dendritic cells (DCs), and to decrease the number of immune suppressive regulatory T cells (Treg) and Myeloid-derived suppressor cells (MDSC) in tumor mass. Moreover, β3-AR blockade on tumor infiltrating lymphocytes (TILs) dampened their ability to secrete IFN-γ, which in turn reduced the PD-L1 expression on NB tumor cells. Further investigations, through a genomic analysis on NB patients, showed that high ADRB3 gene expression correlates negatively with the patient’s clinical outcome compared to the low expression group, and that ADRB3 gene expression is also related to the expression of different immune-checkpoints. Overall, results indicate that β3-AR in NB TME is able to modulate the interaction between tumor and host immune system, and that its antagonism hits multiple pro-tumoral signaling pathways. Citation Format: Gennaro Bruno, Nicoletta Nastasi, Angela Subbiani, Alessia Boaretto, Annalisa Tondo, Claudio Favre, Maura Calvani. β3-adrenergic receptor sustains IFN-γ-dependent PD-L1 expression and impairs anti-tumor immunity in neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3887.

Age-related changes in medial septal cholinergic and GABAergic projection neurons and hippocampal neurotransmitter receptors: relationship with memory impairment.

The hippocampus, which provides cognitive functions, has been shown to become highly vulnerable during aging. One important modulator of the hippocampal neural network is the medial septum (MS). The present study attempts to determine how age-related mnemonic dysfunction is associated with neurochemical changes in the septohippocampal (SH) system, using behavioral and immunochemical experiments performed on young-adult, middle-aged and aged rats. According to these behavioral results, the aged and around 52.8% of middle-aged rats (within the "middle-aged-impaired" sub-group) showed both impaired spatial reference memory in the Morris water maze and habituation in the open field. Immunohistochemical studies revealed a significant decrease in the number of MS choline acetyltransferase immunoreactive cells in the aged and all middle-aged rats, in comparison to the young; however the number of gamma-aminobutyric acid-ergic (GABAergic) parvalbumin immunoreactive cells was higher in middle-aged-impaired and older rats compared to young and middle-aged-unimpaired rats. Western Blot analysis moreover showed a decrease in the level of expression of cholinergic, GABAergic and glutamatergic receptors in the hippocampus of middle-aged-impaired and aged rats in contrast to middle-aged-unimpaired and young rats. The present results demonstrate for the first time that a decrease in the expression level of hippocampal receptors in naturally aged rats with impaired cognitive abilities occurs in parallel with an increase in the number of GABAergic neurons in the MS, and it highlights the particular importance of inhibitory signaling in the SH network for memory function.