Voltage clamp analysis of the effect of excitatory amino acids and derivatives on Purkinje cell dendrites in rat cerebellar slices maintained in vitro.
A voltage clamp analysis of the effects of L-aspartate, L-glutamate and related derivatives on Purkinje cell dendrites was performed in rat cerebellar slices maintained in vitro. Short iontophoretic pulse applications of L-aspartate and L-glutamate in the dendritic field of Purkinje cells induced dose-dependent inward currents with fast onset and recovery. Quisqualate application also gave rise to well developed inward currents with fast onset and slow recovery, whereas N-methyl-D,L-aspartate had no or little effect on Purkinje cell membranes unless prolonged (several seconds) applications were used. Steady applications of low doses of N-methyl-D,L-aspartate much more severely depressed L-aspartate than L-glutamate mediated responses, whereas inward currents due to quisqualate were unaffected. Inward currents due to quisqualate were often more reduced than those due to L-aspartate by steady applications of 2-amino-5-phosphonovalerate, and the antagonistic action of this drug on responses due to L-glutamate was very weak. These results suggest that receptors of Purkinje cells for glutamate and aspartate are different, and are also different from N-methyl-D-aspartate and quisqualate receptors.
D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D046508:Culture Techniques; D003712:Dendrites / Q000187:drug effects*; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D016202:N-Methylaspartate; D010069:Oxadiazoles / Q000494:pharmacology; D011689:Purkinje Cells / Q000187:drug effects*; D016318:Quisqualic Acid; D051381:Rats; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects*
D000596:Amino Acids; D005971:Glutamates; D010069:Oxadiazoles; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D001224:Aspartic Acid; D018698:Glutamic Acid; D016202:N-Methylaspartate; D016318:Quisqualic Acid