Presynaptic long-term changes in excitability of the corticostriatal pathway.
We employed measurements of striatal terminal excitability to monitor the presynaptic effects of tetanic stimulation of corticostriatal fibers. Cortical tetanic stimulation (CTS) initiated a long-lasting decrease in terminal excitability. With higher current CTS, a transient increase in excitability preceded the decrease. However, a long-term increase was induced (1) by a second tetanus applied during the brief elevation in excitability initiated by a previous CTS or (2) when dopamine and GABA transmission were disrupted. A long-term increase also occurred following tetanic stimulation of the striatal terminal field (STS). The direction of the long-lasting change in excitability may depend on the level of polarization of the membrane. These presynaptic mechanisms could be important for the long-term selective modification of striatal synaptic transmission.
Garcia-Munoz
M
M
Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla 92093-0603.
Young
S J
SJ
Groves
P M
PM
D000818:Animals; D001479:Basal Ganglia / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D003342:Corpus Striatum / Q000502:physiology*; D004298:Dopamine / Q000502:physiology; D004558:Electric Stimulation; D004594:Electrophysiology / Q000379:methods; D007608:Kainic Acid / Q000494:pharmacology; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D005680:gamma-Aminobutyric Acid; D007608:Kainic Acid; D004298:Dopamine