Selective potentiation of retinal horizontal cell responses to L-glutamate by D-aspartate.
1. L-Glutamate and L-aspartate depolarize type H1 horizontal cells in the isolated retina of goldfish, but only at millimolar concentrations. 2. When applied in the presence of D-aspartate, L-glutamate depolarizes H1 cells at concentrations nearly 15-fold lower than when it is applied alone. The effects of L-aspartate were not potentiated by either D-aspartate or D-glutamate. 3. Since D-aspartate seems also to enhance the effect of the transmitter released by cone photoreceptors, these results are consistent with the possibility that L-glutamate is a neurotransmitter of cones.
D000818:Animals; D001224:Aspartic Acid / Q000494:pharmacology*; D004357:Drug Synergism; D005971:Glutamates / Q000494:pharmacology* / Q000502:physiology; D018698:Glutamic Acid; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000502:physiology; D010786:Photoreceptor Cells / Q000187:drug effects / Q000502:physiology; D012160:Retina / Q000187:drug effects* / Q000502:physiology; D013237:Stereoisomerism
D005971:Glutamates; D018377:Neurotransmitter Agents; D001224:Aspartic Acid; D018698:Glutamic Acid