[Changes in plasticity of rat hypothalamic neurons and astrocytes in humid and hot environment].

Objective: To study the changes in the plasticity of the neurons and astrocytes in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus of rats exposed to a humid and hot environment.

Methods: The rats were subjected to stimulation with a humid and hot environment for 120 min in a climate chamber (dry bulb temperature of 40.0-/+0.5 degrees C with relative humidity of 60-/+5%). During the exposure, the behavioral responses of the rats were observed, and the changes in the expressions of Fos and GFAP in the PVN and SON in response to the exposure evaluated using immunohistochemical ABC methods.

Results: Exposure to a humid and hot environment caused restlessness and agitation in the rats, which showed increased respiratory frequency and scratching of the face with the forelimbs. Two rats died after the 120-min exposure. Significantly increased expressions of Fos and GFAP were detected in the PVN and SON following the exposure as compared with the control group.

Conclusion: The neurons and astrocytes in the PVN and SON both participate in the regulation of responses to exposure to a humid and hot environment.