Synaptic activation of N-methyl-D-aspartate receptors induces short-term potentiation at excitatory synapses in the striatum of the rat.
We examined the effect of augmenting the activation of N-methyl-D-aspartate receptors during tetanic stimulation of the corpus callosum. Excitatory postsynaptic potentials were recorded from striatal neurons in an in vitro brain slice bathed in either normal or Mg(2+)-free artificial cerebrospinal fluid. Post-tetanic potentiation was followed by a long-lasting depression of the excitatory postsynaptic potential in normal artificial cerebral spinal fluid. Mg(2+)-free artificial cerebrospinal fluid increased the duration of the pretetanus excitatory postsynaptic potential and the amplitude and duration of the direct response to the tetanus. Mg(2+)-free artificial cerebrospinal fluid also enabled the expression of a short-term potentiation of the excitatory postsynaptic potential amplitude and duration. N-methyl-D-aspartate receptor antagonists blocked the induction of all tetanus-induced excitatory postsynaptic potential changes specific to the Mg(2+)-free artificial cerebral spinal fluid. These results indicate that maintained activation of N-methyl-D-aspartate receptors by synaptically released glutamate can produce a sustained enhancement of the excitatory postsynaptic potential. This use-dependent increase in synaptic efficacy may contribute to basal ganglia-related motor performance.
Walsh
J P
JP
Ethel Percy Andrus Gerontology Center, USC Program in Neuroscience, Los Angeles 90089-0191.
Dunia
R
R
D000818:Animals; D001479:Basal Ganglia / Q000187:drug effects; D003337:Corpus Callosum / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D017072:Neostriatum / Q000502:physiology*; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D016194:Receptors, N-Methyl-D-Aspartate; D008274:Magnesium