title: Effect of delta-opioid receptor over-expression on cortical expression of GABAA receptor alpha1-subunit in hypoxia.
abstract: Recent studies show that both delta-opioid receptors (DOR) and GABA receptors play a neuroprotective role in the mature cortex. Since we have observed that DOR over-expression renders the cortex more tolerant to hypoxic stress, we asked whether DOR over-expression affects GABA receptors expression in the cortex under hypoxia. As the first step, we investigated the expression of GABAA receptor alpha1-subunit (GABAA Ralpha1, the most abundant alpha-subunit of GABA receptors in the adult brain) in the mouse cortex with transgenic DOR over-expression after hypoxia. The results showed that GABAA Ralpha1 expression was lower in the transgenic than wild-type cortex, suggesting that DOR overexpression induces an inhibitory effect on GABAA receptor expression. Hypoxia for 1-3 days significantly increased GABAA Ralpha1 expression in the wild-type cortex, which may be an adaptive strategy for protecting the cortex against hypoxic stress. Interestingly, such increase was not found in the transgenic cortex with DOR over-expression. This may represent an interactive regulation in the transgenic cortex to efficiently balance energy production and consumption for better adaptation to hypoxic environment. Since DOR over-expression increases cortical tolerance to hypoxia, an increase in GABA receptors expression (an energy-costing process) may not be necessary in the cortex with DOR over-expression.
authors.affiliation: First Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Feng
authors.forename: Xiaozhou
authors.initials: X
authors.lastname: He
authors.forename: Yilin
authors.initials: Y
authors.lastname: Yang
authors.forename: Jingshan
authors.initials: J
authors.lastname: Chen
authors.forename: Kaisheng
authors.initials: K
authors.lastname: Yin
authors.forename: Ying
authors.initials: Y
authors.lastname: Xia
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D015870:Gene Expression / Q000502:physiology; D000860:Hypoxia / Q000235:genetics / Q000503:physiopathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011963:Receptors, GABA-A / Q000235:genetics*; D017465:Receptors, Opioid, delta / Q000235:genetics*; D013312:Stress, Physiological / Q000502:physiology; D015854:Up-Regulation / Q000502:physiology
chemical_list: D011963:Receptors, GABA-A; D017465:Receptors, Opioid, delta