Recurrent inhibition in amygdalo-cortical projection neurons of the rat via collaterals of fast-conducting axons.
On stimulation of the medial prefrontal cortex (mPFC) of the rat, the amygdala neurons projecting to the mPFC exhibited an IPSP, which caused IS-SD blockage in the antidromic spikes of these neurons. The IPSP was not preceded by EPSP, but was not monosynaptic in nature. Its onset latencies were mostly confined to within 10 ms, which was shorter than the time for orthodromic conduction from the mPFC to the amygdala. The findings indicated that the IPSP was produced via recurrent collaterals of the amygdalo-cortical projection neurons. In view of the wide range of distribution of the time for antidromic conduction in the amygdalo-cortical projection neurons (3.4-27.2 ms), the projection neurons with a fast-conducting axon were considered to be responsible for the mPFC-evoked recurrent IPSP.
Matsuda
Y
Y
Department of Physiology, Nagasaki University School of Medicine, Japan.
Fujimura
K
K
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001369:Axons / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology