Premium
Effects of noradrenaline on the GABA response in rat isolated spiral ganglion neurons in culture
Author(s) -
Zha DingJun,
Wang ZhiMing,
Lin Ying,
Liu Tao,
Qiao Li,
Lu LianJun,
Li YunQing,
Qiu JianHua
Publication year - 2007
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2007.04776.x
Subject(s) - chelerythrine , medicine , endocrinology , protein kinase a , chemistry , forskolin , protein kinase c , spiral ganglion , biology , kinase , biochemistry , neuroscience , stimulation , inner ear
In the present study, the modulatory effects of noradrenaline (NA) on the GABA response were investigated in the isolated cultured spiral ganglion neurons of rat by using nystatin perforated patch recording configuration under voltage‐clamp conditions. NA reversibly depressed GABA response in a concentration‐dependent manner and neither changed the reversal potential of the GABA response nor affected the apparent affinity of GABA to its receptor. α2‐adrenoceptor agonist and antagonist, clonidine and yohimbine mimicked and blocked the NA action on the GABA response, respectively. N ‐[2(methylamino)ethyl]‐5‐isoquinoline sulfonamide dihydrochloride (H‐89), a protein kinase A inhibitor, mimicked the effect of NA on the GABA response. NA failed to affect the GABA response in the presence of both cAMP and protein kinase A modulator. However, NA still depressed the GABA response even in the presence of both phorbol‐12‐myristate‐13‐acetate, a protein kinase C activator and chelerythrine, a protein kinase C inhibitor. These results suggest that the NA suppression of the GABA response is mediated by α2‐adrenoceptor which reduces intracellular cAMP formation through the inhibition of adenylyl cyclase. Therefore, NA input to the spiral ganglion neurons may modulate the auditory transmission by affecting the GABA response.