The central amygdala (CeA) is a crucial modulator of emotional, behavioral, and autonomic functions, including cardiovascular responses. Despite its importance, the specific circuit by which the CeA modulates blood pressure remains insufficiently explored. Our investigations demonstrate that photostimulation of GABAergic neurons in the centromedial amygdala (CeM^GABA), as opposed to those in the centrolateral amygdala (CeL), produces a depressor response in both anesthetized and freely-moving mice. In addition, activation of CeM^GABA axonal terminals projecting to the nucleus tractus solitarius (NTS) significantly reduces blood pressure. These CeM^GABA neurons form synaptic connections with NTS neurons, allowing for the modulation of cardiovascular responses by influencing the caudal or rostral ventrolateral medulla. Furthermore, CeM^GABA neurons targeting the NTS receive dense inputs from the CeL. Consequently, stimulation of CeM^GABA neurons elicits hypotension through the CeM-NTS circuit, offering deeper insights into the cardiovascular responses associated with emotions and behaviors.
Animals ; GABAergic Neurons/physiology* ; Male ; Central Amygdaloid Nucleus/physiopathology* ; Hypotension/physiopathology* ; Mice ; Blood Pressure/physiology* ; Mice, Inbred C57BL ; Solitary Nucleus/physiology* ; Photic Stimulation ; Neural Pathways/physiology*

Objective: To investigate the levels of vitamin D and the correlation between DPN and vitamin D in elderly patients with diabetic peripheral neuropathy(DPN). Methods: A total of 849 patients aged 60 years and over admitted into endocrinology department from June 2016 to September 2017 were enrolled in this retrospective case-control study.According to DPN diagnostic criteria, patients were divided into the non-DPN group(n=542)and the DPN group(n=307). The 25(OH)-vitamin D[25(OH)D]level and blood biochemical parameters were determined and compared between the two groups.The risk factors for DPN were analyzed using logistic regression analysis and plotting receiver operating characteristic(ROC)curves. Results: The mean of serum 25(OH)D level in the 849 patients was 43.9±19.4 nmol/L.Serum 25(OH)D level was lower in the DPN patients than in the non-DPN patients[(40.9±20.4)nmol/L vs.(45.7±18.6)nmol/L, P<0.05]. The incidence of 25(OH)D deficiency was higher in the DPN group than in the non-DPN group(72.3% or 222/307 vs. 64.6% or 350/542, P<0.05). Binary logistic regression analysis indicated that 25(OH)D was a protective factor for DPN(OR=0.980, 95% CI: 0.964~0.995, P<0.05)and the disease duration was a risk factor for DPN(OR=1.048, 95% CI: 1.027~1.070, P<0.001). ROC analysis indicated that the diagnostic cut-off value of serum 25(OH)D for predicting DPN was 37.5nmol/L, with a Youden index of 0.17, sensitivity of 0.65 and specificity of 0.52. Conclusions The 25(OH)D level is much lower in diabetic patients, especially in DPN patients.Higher 25(OH)VD level might be a protective factor for DPN, and vitamin D might be one of potential biomarkers for DPN in diabetic patients.