Cerebellar long-term potentiation under suppressed postsynaptic Ca2+ activity.
To study the roles of postsynaptic Ca2+ activity in cerebellar synaptic plasticity, we used a patch-recording technique in Purkinje cell dendrites. While the combination of parallel fibre stimulation and 8-bromo cyclic guanosine monophosphate (Br-cGMP) application produced long-term depression (LTD) of the parallel fibre/Purkinje cell transmission, the same stimuli evoked long-term potentiation (LTP) during postsynaptic injection of Ethyleneglycol-bis-(beta-amino-ethylether)-N, N, N', N'-tetraacetate (EGTA). Furthermore, in the presence of alpha-aminobutyric acid (GABA), parallel fibre stimulation plus Br-cGMP produced LTP of extracellular K+ increases following parallel fibre stimulation. These results suggest that postsynaptic Ca2+ activity in Purkinje cells is negatively correlated to the direction of plastic changes and that the Ca2+ changes and cGMP play distinct roles in cerebellar synaptic plasticity.
Shibuki
K
K
Laboratory for Neural Networks, Frontier Research Program, Saitama, Japan.
Okada
D
D
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism / Q000502:physiology*; D006152:Cyclic GMP / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000378:metabolism*; D013997:Time Factors
D006152:Cyclic GMP; D002118:Calcium