Hemorrhagic shock is a common clinical emergency that can aggravate cell injury after resuscitation. Astrocytes are crucial for the survival of neurons because they regulate the surrounding ionic microenvironment of neurons. Although hemorrhagic shock and resuscitation (HSR) injury can impair cognition, it remains unclear how this insult directly affects astrocytes. In this study, we established an HSR model by bleeding and re-transfusion in mice. The social interaction test and new object recognition test were applied to evaluate post-operative cognitive changes, and the results suggest that mice experience cognitive impairment following exposure to HSR. In the HSR group, the power spectral density of β and γ oscillations decreased, and the coupling of the θ oscillation phase and γ oscillation amplitude was abnormal, which indicated abnormal neuronal oscillation and cognitive impairment after HSR exposure. In brief, cognitive impairment in mice is strongly correlated with Ca²⁺ signal strength in lateral septum astrocytes following HSR.
Animals ; Astrocytes/metabolism* ; Shock, Hemorrhagic/metabolism* ; Resuscitation/adverse effects* ; Male ; Mice ; Calcium Signaling/physiology* ; Mice, Inbred C57BL ; Septal Nuclei/metabolism* ; Cognitive Dysfunction/etiology* ; Disease Models, Animal ; Cognition Disorders/etiology*

Sexual dimorphism in the brain underlies behavioral differences between sexes. The bed nucleus of the stria terminalis (BNST) is a complex nucleus that differs between males and females, but the sexual dimorphism in cytoarchitecture and the connectome of its oval subdivision (ovBNST) remains largely unexplored. By combining snRNA-seq and transgenic labeling, we found a higher density of ovBNST proenkephalin (ovBNST^PENK) neurons in male than female mice. Anatomically, we virally mapped the efferents and afferents of ovBNST^PENK neurons, finding reciprocally dimorphic connections with the hypothalamus and striatum. Gene enrichment analysis suggests that ovBNST^PENK neurons are modulated by the upstream dopamine pathway. Functionally, by applying caspase-3-mediated depletion of ovBNST^PENK neurons, we found that loss of these neurons enhanced locomotor activity in male but not female mice, without altering the anxiety-like phenotypes in either sex. Our study may pave the way for a better understanding of the anatomical and functional profiles of ovBNST^PENK neurons from a sexually dimorphic perspective.
Animals ; Male ; Female ; Septal Nuclei/physiology* ; Sex Characteristics ; Neurons/physiology* ; Enkephalins/metabolism* ; Mice ; Mice, Transgenic ; Protein Precursors/metabolism* ; Mice, Inbred C57BL ; Neural Pathways/physiology*

Neuropathic pain is a chronic condition caused by damage or dysfunction in the nervous system. While the spleen may influence neuropathic pain, its role has been poorly understood. This study demonstrates that the spleen plays a crucial role in regulating neuropathic pain through the bed nucleus of the stria terminalis (BNST) - paraventricular nucleus of the hypothalamus (PVN) neural circuit in a chronic constriction injury (CCI) mouse model. Splenectomy, splenic denervation, or splenic sympathectomy significantly increased the mechanical withdrawal threshold (MWT) and reduced macrophage infiltration in the dorsal root ganglia (DRG) of CCI mice. Pseudorabies virus injections into the spleen revealed connections to the BNST and PVN in the brain. Chemogenetic inhibition of the BNST-PVN circuit increased macrophage infiltration in the DRG and decreased the MWT; these effects were reversed by splenectomy, splenic denervation, or sympathectomy. These findings underscore the critical role of the spleen, regulated by the BNST-PVN circuit, in neuropathic pain.
Animals ; Neuralgia/pathology* ; Septal Nuclei/physiopathology* ; Male ; Spleen/physiopathology* ; Paraventricular Hypothalamic Nucleus/physiopathology* ; Mice, Inbred C57BL ; Splenectomy ; Mice ; Neural Pathways/physiopathology* ; Disease Models, Animal ; Ganglia, Spinal/physiopathology* ; Sympathectomy ; Macrophages

OBJECTIVE: To observe the effect of Shugan Tiaoshen acupuncture (acupuncture for soothing the liver and regulating the spirit) on the protein kinase C/extracellular signal-regulated kinase/cAMP response element-binding protein (PKC/ERK/CREB) signaling pathway in the bed nucleus of the stria terminalis (BNST) of rats with post-traumatic stress disorder (PTSD), and to explore the mechanism of acupuncture on alleviating anxiety and fear in PTSD. METHODS: Fifty SPF-grade male SD rats were randomly divided into a blank group (10 rats) and a PTSD model group (40 rats). The PTSD model was induced by using a combination of closed electric shock and forced exhaustive swimming. Thirty successfully modeled rats were randomly assigned to a model group, a medication group, and an acupuncture group, with 10 rats in each group. The rats in the medication group were treated with paroxetine hydrochloride solution by gavage, once daily for 12 consecutive days. The rats in the acupuncture group were treated with acupuncture at "Baihui" (GV 20) and bilateral "Neiguan" (PC 6), "Shenmen" (HT 7), "Taichong" (LR 3). "Baihui" (GV 20) was needled daily, while the other acupoints were alternately needled on the left side on odd days and the right side on even days, once daily for 12 consecutive days. Anxiety and fear behaviors changes were assessed by using the open field test and elevated plus maze test. Histological changes in the BNST were observed by using HE staining and Nissl staining. The expression of PKC, phosphorylated PKC (p-PKC), ERK1/2, phosphorylated ERK1/2 (p-ERK1/2), and p-CREB proteins in the BNST were detected by using Western blot. RESULTS: Compared with the blank group, the model group showed decreased time and total distance spent in the center of the open field and on the open arms of the elevated plus maze (P<0.05); the BNST tissues in the model group exhibited a reduced number of neurons, disorganized cell arrangement, cell shrinkage, nuclear condensation, abnormal neuronal structure, uneven Nissl staining, and reduced Nissl bodies. The model group showed increased protein expression of p-PKC and p-PKC/PKC ratio (P<0.05) and decreased protein expression of p-ERK1/2, p-CREB, and p-ERK1/2/ERK1/2 ratio (P<0.05). Compared with the model group, the medication group and the acupuncture group showed increased time and total distance spent in the center of the open field and on the open arms of the elevated plus maze (P<0.05); the BNST tissues showed increased number of neurons, more organized cell arrangement, improved neuronal structure, and increased Nissl bodies; the medication group and the acupuncture group also showed decreased p-PKC protein expression and p-PKC/PKC ratio (P<0.05) and increased p-ERK1/2, p-CREB protein expression, and p-ERK1/2/ERK1/2 ratio (P<0.05). CONCLUSION Shugan Tiaoshen acupuncture could alleviate anxiety and fear behaviors in PTSD rats, and improve neuronal damage in the BNST. The mechanism may be related to the regulation of the PKC/ERK/CREB signaling pathway in the BNST.
Animals ; Male ; Rats ; Rats, Sprague-Dawley ; Acupuncture Therapy ; Protein Kinase C/metabolism* ; Stress Disorders, Post-Traumatic/metabolism* ; Anxiety/metabolism* ; Cyclic AMP Response Element-Binding Protein/metabolism* ; Humans ; Septal Nuclei/metabolism* ; Signal Transduction ; Extracellular Signal-Regulated MAP Kinases/metabolism* ; Acupuncture Points ; Behavior, Animal

The nucleus accumbens (NAc) plays an important role in various emotional and motivational behaviors that rely on heightened wakefulness. However, the neural mechanisms underlying the relationship between arousal and emotion regulation in NAc remain unclear. Here, we investigated the roles of a specific subset of inhibitory corticotropin-releasing hormone neurons in the NAc (NAc^CRH) in regulating arousal and emotional behaviors in mice. We found an increased activity of NAc^CRH neurons during wakefulness and rewarding stimulation. Activation of NAc^CRH neurons converts NREM or REM sleep to wakefulness, while inhibition of these neurons attenuates wakefulness. Remarkably, activation of NAc^CRH neurons induces a place preference response (PPR) and decreased basal anxiety level, whereas their inactivation induces a place aversion response and anxious state. NAc^CRH neurons are identified as the major NAc projection neurons to the bed nucleus of the stria terminalis (BNST). Furthermore, activation of the NAc^CRH-BNST pathway similarly induced wakefulness and positive emotional behaviors. Taken together, we identified a basal forebrain CRH pathway that promotes the arousal associated with positive affective states.
Animals ; Septal Nuclei/metabolism* ; Nucleus Accumbens/physiology* ; Corticotropin-Releasing Hormone/metabolism* ; Wakefulness/physiology* ; Neurons/metabolism* ; Male ; Mice ; Mice, Inbred C57BL ; Neural Pathways/physiology* ; Anxiety/physiopathology* ; Reward

Nociceptin/orphanin FQ (N/OFQ) and its receptor, nociceptin opioid peptide (NOP) receptor, are localized in brain areas implicated in depression including the amygdala, bed nucleus of the stria terminalis, habenula, and monoaminergic nuclei in the brain stem. N/OFQ inhibits neuronal excitability of monoaminergic neurons and monoamine release from their terminals by activation of G protein-coupled inwardly rectifying K⁺ channels and inhibition of voltage sensitive calcium channels, respectively. Therefore, NOP receptor antagonists have been proposed as a potential antidepressant. Indeed, mounting evidence shows that NOP receptor antagonists have antidepressant-like effects in various preclinical animal models of depression, and recent clinical studies again confirmed the idea that blockade of NOP receptor signaling could provide a novel strategy for the treatment of depression. In this review, we describe the pharmacological effects of N/OFQ in relation to depression and explore the possible mechanism of NOP receptor antagonists as potential antidepressants.
Amygdala ; Antidepressive Agents ; Brain ; Brain Stem ; Calcium Channels ; Depression ; Habenula ; Models, Animal ; Neurons ; Neuropeptides ; Opioid Peptides ; Receptors, Drug ; Septal Nuclei

OBJECTIVES: Disrupted integrities of the fornix and stria terminalis have been suggested in schizophrenia. However, very few studies have focused on the fornix and stria terminalis comparing first-episode schizophrenia (FESZ), chronic schizophrenia (CS), and healthy controls (HCs) with the application of diffusion-tensor imaging (DTI) technique. The objective of this study is to compare the connectivity of the fornix and stria terminalis among FESZ, CS, and HCs. METHODS: We included the 44 FESZ patients, 39 CS patients and 20 HCs in this study. Voxel-wise statistical analysis of the fractional anisotropy (FA) data was performed using Tract-Based Spatial Statistics to analyze the connectivity of fornix and stria terminalis. In addition, the Scale for the Assessment of Positive Symptoms (SAPS) and the Scale for the Assessment of Negative Symptoms (SANS) were used to evaluate clinical symptom severities. RESULTS: There were no significant differences between the FESZ, CS, and HCs in age, sex, education years. The SAPS and SANS scores of the schizophrenia groups showed no significant differences. FA values of the right fornix cres/stria terminalis in the CS group were significantly lower than those in FESZ and HCs. There were no significant differences of FA values of the right fornix cres/stria terminalis between the FESZ and the HCs. Pearson correlation analyses revealed that significant correlation between FA values of the right fornix cres/stria terminalies of the the FESZ group and positive, negative symptom scales, and FA values of the right fornix cres/stria terminalis of the CS group and negative symptom scales. CONCLUSIONS: This study shows that FA values of the fornix and stria terminalis in the CS were lower than in the FESZ and the HCs. These results suggest that the fornix and stria terminalis can play a role in pathophysiology of schizophrenia. Thus current study can broaden our understanding of the pathophysiology of schizophrenia.
Anisotropy ; Education ; Fornix, Brain ; Humans ; Schizophrenia ; Septal Nuclei ; Weights and Measures ; White Matter

OBJECTIVE: The hallmark of anxiety disorders is excessive fear. Previous studies have suggested that selective neural projections from Basal nucleus of stria terminalis (BNST) to amygdala and vice-versa precisely control the fear learning process. However the exact mechanism how the BNST controls fear consolidation and its extinction is largely unknown. In the present study we observed the changes in the BNST sub-regions following fear conditioning and its extinction. METHODS: The change in the number of positive neurons was determined by immunohistochemistry for Acetyl H3 (Histone 3), Acetyl H4 (Histone 4), cAMP response element binding Protein (CBP) and c-fos in three sub-regions of the BNST namely the anterio-lateral BNST (STLP) and anterio-medial BNST (STMA), and lateral-ventral BNST (STLV) of rats subjected to auditory fear conditioning and extinction. RESULTS: We found significant increase in the number of CBP, acetyl H3 and acetyl H4 positive neurons in the STMA and STLV but not in the STLP after fear conditioning. However, following fear extinction the number of CBP, acetyl H3 and acetyl H4 positive neurons increased significantly in the STLP but not in the STMA and STLV. Similar changes were observed in the number of c-fos positive neurons after fear consolidation and extinction. CONCLUSION: The results from this study suggest that the differential histone acetylation in the different sub-regions of the BNST following fear learning and its extinction may be responsible for changes in the neuronal activation patterns resulting in either fear or less fear.
Acetylation* ; Amygdala ; Animals ; Anxiety Disorders ; Cyclic AMP Response Element-Binding Protein ; Histones* ; Immunohistochemistry ; Learning ; Neurons ; Rats ; Septal Nuclei*

The hippocampus is known as involved in learning and memory functions and the entorhinal cortex plays a crucial role as a gateway connecting the several areas and hippocampal formation. Entorhinal cortex lesions have been employed in numerous studies as the Alzheimer's disease model. The purpose of this study were to identify the CNS hip-pocampal and cholinergic pathway and to investigate the morphological changes of the hippocampal cholinergic inner-vations by using the Pseudorabies virus injection into the hippocampus after entorhinal cortex lesions. The pseudorabies virus and double labelled neurons (ChAT and PRV) were distributed at several different nuclei including agranular insular cortex, bed nucleus of stria terminalis, central amygdala, globus pallidus, lateral segment, lateral hypothalamic area, laterodorsal tegmental nucleus, medial septal nucleus, mesencephalic reticular nucleus, periaqueductal gray matter and substantia innominata The morphological changes were observed in the hippocampal cholinergic innervation after entorhinal cortex lesions. These data suggested that the hippocampal cholinergic innervation showed morphological changes throughout the whole brain areas after entorhinal cortex lesion.
Alzheimer Disease ; Amygdala ; Animals ; Brain ; Entorhinal Cortex* ; Globus Pallidus ; Herpesvirus 1, Suid ; Hippocampus* ; Hypothalamic Area, Lateral ; Learning ; Memory ; Neurons ; Periaqueductal Gray ; Rats* ; Septal Nuclei ; Substantia Innominata

It has been proposed that nitric oxide is involved in the pathogenesis of cerebral ischemia-reperfusion. Because superoxide production is also enhanced during reperfusion, the cytotoxic oxidant peroxynitrite could be formed, but it is not known if this occurs following global forebrain ischemia-reperfusion. We examined whether peroxynitrite generation is increased in the vulnerable regions after forebrain ischemia-reperfusion. Transient forebrain ischemia was produced in the conscious rat by four-vessel occlusion. Rats were subjected to 10 or 15 min of forebrain ischemia. Immunohistochemical method was used to detect 3-nitrotyrosine, a marker of peroxynitrite production. 3-Nitrotyrosine immunoreactivity was enhanced in the hippocampal CA1 area 3 days after reperfusion. Furthermore, in rats subjected to ischemia for 15 min, this change was also observed in the lateral striatal region and the lateral septal nucleus 2apprx3 days after reperfusion. The cresyl violet staining of adjacent sections showed that neuronal cell death was induced in parallel with the nitrotyrosine immunoreactivity in the hippocampal CA1 area and the lateral striatal region. Our findings suggest that oxygen free radical accumulation and consequent peroxynitrite production play a role in neuronal death caused by cerebral ischemia-reperfusion.
Animals ; Brain* ; Cell Death ; Ischemia* ; Neurons ; Nitric Oxide ; Oxygen ; Peroxynitrous Acid* ; Prosencephalon* ; Rats* ; Reperfusion ; Septal Nuclei ; Superoxides ; Viola