Short-term depression of synaptic transmission from rat lateral geniculate nucleus to primary visual cortex in vivo.
Two forms of short-term synaptic plasticity, paired-pulse depression (PPD) and frequency depression, were prominent in the adult rat geniculo-cortical visual pathway in vivo. Iontophoresis of GABAa receptor antagonist (bicuculline methiodide) or GABAb receptor antagonist (2-hydroxy-saclofen) in the primary visual cortex significantly reduced the short-term synaptic depression. When NMDA or AMPA/kainate receptors were blocked, no obvious change of synaptic depression was observed. Application of high [Ca(2+)] enhanced the short-term synaptic depression. Our results suggest that the presynaptic Ca(2+)-dependent neurotransmitter depletion and postsynaptic GABAergic inhibition may be crucial for short-term synaptic depression in the geniculo-cortical pathway.
Jia
Fan
F
Vision Research Laboratory, School of Life Sciences, University of Science and Technology of China, 96 Jingzhai Road, Hefei, Anhui 230027, PR China.
Xie
Xiaoqiao
X
Zhou
Yifeng
Y
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D005829:Geniculate Bodies / Q000187:drug effects / Q000502:physiology*; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D014793:Visual Cortex / Q000187:drug effects / Q000502:physiology*
D002118:Calcium; D001640:Bicuculline