Author(s): HE Defu, CHEN Fujun, ZHOU Shaoci
Pages: 374-378
Year: 2004 Issue:  3
Journal: ACTA PHYSIOLOGICA SINICA
Keyword:  lateral amygdaloid nucleus; A Ⅰ cortex; acoustic response; inhibition; GABA;
Abstract: Experiments were performed on Sprague Dawley rats with multibarrel microelectrode technique. The effects of acoustic response of A Ⅰ cortex neurons produced by electrical stimulation of lateral amygdaloid nucleus (LA) and the influence of GABA were observed. Experimental results showed that iontophoretic administration of GABA caused a pronounced inhibition of the electrical activity of A- Ⅰ neurons. Blockade of GABAA with bicuculline (BIC) facilitated the acoustic response. The acoustic response of A- Ⅰ neurons was inhibited when the LA was stimulated. Iontophoretic application of GABA resulted in a similar inhibitory effect as that of LA stimulation. Blockade of GABAA with bicuculline reversed the inhibitory effect of LA stimulation on the acoustic response of A- Ⅰ neurons. In contrast, application of strychnine, a glycine receptor antagonist, could not reverse the inhibitory effect of LA. Baclofen, a GABAB agonist, did not affect the acoustic response of the auditory neurons. These results indicate that GABA is the ultimate transmitter which mediates the LA stimulation-induced inhibition of the acoustic response of A- Ⅰ neurons in rats, possibly via the GABAAreceptor.