Effects of Heat Stress on the Development of GABAergic Neurons in the HPG Axis of Wenchang Chicks

This study conducted an in-depth investigation on the development of GABAergic neurons and their receptors in HPG axis-related target organs of VVenchang chicks under heat stress. One-day-old healthy Wenchang chicks were randomly divided into control (CK) and heat stress (HS) groups. Chicks in the HS group were placed in a 40 +/- 0.5 degrees C climatic chamber for HS treatment from 13:00 to 15:00 daily. By immunohistochemistry and Western blotting, GABA and GABA(A), receptor (GABA(A)R) expression in the hypothalamus of the HS group was significantly higher (p<0.05), but GABA(B), receptor (GABA(B)R) expression was significantly lower than that of the CK group (p<0.05). Expression of GABA and its two receptors in the pituitary tissues of the HS group was significantly lower than in the CK group (p<0.05). Expression of GABA and GABA(B)R in ovaries in the HS group was significantly higher, but expression of GAB/\R in the testes of the HS group was lower than that of the CK group (p<0.05). In the male chicks, expression of GABA and its two receptors in the hypothalamus, pituitary, and testicular tissues of the HS group was significantly higher than that of the CK group (p<0.05). Western blotting showed that the GABA(A)R and GABA(B)R expression of the HS group was significantly higher than that of the CK group at 3 and 5 weeks of age. Thus, HS caused GABAergic nervous system disorder in the HPG axis of Wenchang chicks and seriously hindered the normal development of GABAergic neurons in chicks, leading to the disorder of the expression of GABA and its receptors in tissues.