Project description:Acute stress-induced anxiety is an important way for animals to avoid danger. However, neural and molecular mechanisms that underlie control of anxiety behavior are largely elusive. Here, we find acute physical stress activates a large number of neurons in the primary somatosensory cortex, trunk region (S1Tr). Single-cell sequencing reveals the S1Tr c-fos positive neurons activated by acute stress are largely GABAergic somatostatin (Sst) neurons. These S1TrSst neurons activated by acute stress showed desensitization during subsequent anxiety-like behavior tests. Selective inhibition or apoptosis of S1TrSst neurons mimics acute stress effects to induce anxiety. In contrast, selective activation of S1TrSst neurons reduced acute stress-induced anxiety. Furthermore, we demonstrate that S1TrSst cells receive inputs from the secondary auditory cortex, dorsal area (AUD) GABAergic neurons to modulate acute stress-induced anxiety. Finally, from the results of spatial transcriptome sequencing and precise projection-specificity Pde4b protein knockdown strategy, we show that acute stress reduces Pde4b-regulated cyclic adenosine monophosphate (cAMP) signaling pathway activity in the AUDGABA-S1TrSst projections and resulting in a hypoactivity of S1TrSst neurons during subsequent behavioral tests. Our study unveils a neural and molecular mechanism for acute stress-elicited anxiety and affords a theoretical basis for clinical treatment of anxiety disorders.
Project description:Acute stress-induced anxiety is an important way for animals to avoid danger. However, neural and molecular mechanisms that underlie control of anxiety behavior are largely elusive. Here, we find acute physical stress activates a large number of neurons in the primary somatosensory cortex, trunk region (S1Tr). Single-cell sequencing reveals the S1Tr c-fos positive neurons activated by acute stress are largely GABAergic somatostatin (Sst) neurons. These S1TrSst neurons activated by acute stress showed desensitization during subsequent anxiety-like behavior tests. Selective inhibition or apoptosis of S1TrSst neurons mimics acute stress effects to induce anxiety. In contrast, selective activation of S1TrSst neurons reduced acute stress-induced anxiety. Furthermore, we demonstrate that S1TrSst cells receive inputs from the secondary auditory cortex, dorsal area (AUD) GABAergic neurons to modulate acute stress-induced anxiety. Finally, from the results of spatial transcriptome sequencing and precise projection-specificity Pde4b protein knockdown strategy, we show that acute stress reduces Pde4b-regulated cyclic adenosine monophosphate (cAMP) signaling pathway activity in the AUDGABA-S1TrSst projections and resulting in a hypoactivity of S1TrSst neurons during subsequent behavioral tests. Our study unveils a neural and molecular mechanism for acute stress-elicited anxiety and affords a theoretical basis for clinical treatment of anxiety disorders.
Project description:Both the amygdala and the bed nucleus of the stria terminalis (BNST) have been implicated in maladaptive anxiety characteristic of anxiety disorders. However, the underlying circuit and cellular mechanisms have remained elusive. Here we show that mice with Erbb4 gene deficiency in somatostatin-expressing (SOM+) neurons exhibit heightened anxiety as measured in the elevated plus maze test and the open field test, two assays commonly used to assess anxiety-related behaviors in rodents. Using a combination of electrophysiological, molecular, genetic and pharmacological techniques we demonstrate that the abnormal anxiety in the mutant mice is caused by enhanced excitatory synaptic inputs onto SOM+ neurons in the central amygdala (CeA), and the resulting reduction in inhibition onto downstream SOM+ neurons in the BNST. Notably, our results indicate that an increase in dynorphin signaling in SOM+ CeA neurons mediates the paradoxical reduction in inhibition onto SOM+ BNST neurons, and that the consequent enhanced activity of SOM+ BNST neurons is both necessary for and sufficient to drive the elevated anxiety. Finally, we show that the elevated anxiety and the associated synaptic dysfunctions and increased dynorphin signaling in the CeA-BNST circuit of the Erbb4 mutant mice can be recapitulated by stress in wild-type mice. Together, our results unravel previously unknown circuit and cellular processes in the central extended amygdala that can cause maladaptive anxiety.
Project description:Glucagon (GCG) analogues are gaining attention as promising components in incretin-based therapeutics for obesity and metabolic dysfunction-associated steatohepatitis. However, the biology of chronic glucagon treatment, in particular, the molecular underpinnings of GCG-induced energy expenditure and lipid metabolism, remain poorly defined. We utilized a long-acting GCG analogue (LA-GCG) in conjunction with hepatic and adipose glucagon receptor knockout mouse models. Through an integrative approach that combined metabolic, biochemical and omics techniques, we investigated the molecular mechanisms underlying GCG-induced energy expenditure and metabolic benefits. We demonstrate that the LA-GCG enhances energy expenditure in diet-induced obese mice with an essential role of hepatic, but not adipose, GCGR signaling. Intriguingly, the enhancement in energy expenditure is observed only in obese but not in lean mice. The preferential efficacy is plausibly found in a prolonged activation of cAMP/PKA signaling through PDE4B/4D downregulation by LA-GCG. Conversely, the cAMP/PKA signaling is promptly attenuated by the PDE4B/4D activity in lean mice. Interestingly, unlike the EE phenotype, the lipid-clearing capacity of LA-GCG is independent of the PDE4/cAMP/PKA axis. These findings provide the molecular basis for GCG-induced energy expenditure and metabolic benefits and suggest the phenotypic segregation of cAMP/PKA-dependent and independent effects.
Project description:Anxiety is elicited by excessive apprehension about unpredictable threats. However, the neural circuit governing unpredictable threat induced anxiety remains unclear. Here, we found ventral bed nucleus of the stria terminalis (vBNST) GABAergic neurons displayed selective activation to unpredictable threats by means ofthrough coordinated excitatory input from insular cortex (IC) glutamergic neurons and inhibitory input from lateral nucleus of the amygdala (CeL) somatostatin (SOM) neurons. Using activity-dependent neuronal tagging technology, we found that unpredictable threat responsive cells in vBNST drive freezing and anxiety via projections to ventral lateral periaqueductal grey (vlPAG) and median nucleus of the amygdala (CeM) respectively. Finally, we identified KCNQ3 plays an essential role in hyperactivity of vBNST GABAergic neurons and induced anxiety. These data identified a forward inhibitory circuit that determine the selective activation of vBNST in unpredictable threat and anxiety, and suggest that Kcnq3 KCNQ3 channel acts as a promising target in treatment of anxiety disorder following unpredictable stress.
Project description:Investigating the molecular basis and correlates of anxiety-related and depression-like behaviors, we generated a mouse model consisting of high (HAB) and low (LAB) anxiety-related behavior mice. We utilized the elevated plus-maze for testing the genetic predisposition to anxiety-related behavior and, consequently, used this as selection criterion for the inbreeding of our animals. In depression-related tests, HAB mice display a more passive, depression-like coping strategy than LAB mice, resembling clinical comorbidity of anxiety and depression as observed in psychiatric patients. Using a microarray approach, the hypothalamic paraventricular nucleus (PVN), the basolateral/lateral (BLA), the medial (MeA) and central amygdala (CeA), the nucleus accumbens (NAc), the cingulate cortex (Cg) and the supraoptic nucleus (SON) – centers of the central nervous anxiety and fear circuitries – were investigated and screened for differences between HAB and LAB mice. Analysis was performed from six animals per line (HAB and LAB, respectively) pooled per brain region in ten technical replicates, thereof five with a dye-swapped design giving a total of 70 array slides analyzed. The LAB mouse line is referred to as reference.
Project description:Background & Aims: Glucagon (GCG) analogues are gaining attention as promising components in incretin-based therapeutics for obesity and metabolic dysfunction-associated steatohepatitis. However, the biology of chronic glucagon treatment, in particular, the molecular underpinnings of GCG-induced energy expenditure and lipid metabolism, remain poorly defined. Methods: We utilized a long-acting GCG analogue (LA-GCG) in conjunction with hepatic and adipose glucagon receptor knockout mouse models. Through an integrative approach that combined metabolic, biochemical and omics techniques, we investigated the molecular mechanisms underlying GCG-induced energy expenditure and metabolic benefits. Results: We demonstrate that the LA-GCG enhances energy expenditure in diet-induced obese mice with an essential role of hepatic, but not adipose, GCGR signaling. Intriguingly, the enhancement in energy expenditure is observed only in obese but not in lean mice. The preferential efficacy is plausibly found in a prolonged activation of cAMP/PKA signaling through PDE4B/4D downregulation by LA-GCG. Conversely, the cAMP/PKA signaling is promptly attenuated by the PDE4B/4D activity in lean mice. Interestingly, unlike the EE phenotype, the lipid-clearing capacity of LA-GCG is independent of the PDE4/cAMP/PKA axis. Conclusions: These findings provide the molecular basis for GCG-induced energy expenditure and metabolic benefits and suggest the phenotypic segregation of cAMP/PKA-dependent and independent effects.