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*

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