Plasticity of responses to synaptic inputs in rat ventral striatal neurons after repeated administration of the dopamine D2 antagonist raclopride.
The effects of acute and repeated systemic administration of the dopaminergic D2 antagonist raclopride on responses of ventral striatal neurons were examined in chloral hydrate-anesthetized rats. Stimulating electrodes were placed in the entorhinal and perirhinal cortices, medial thalamus, and prelimbic cortex. Stimulation in water-injected control rats evoked one or occasionally two action potentials. Results were similar in rats injected acutely with raclopride (4 or 8 mg/kg) except that a small proportion of cells (5%) produced burst responses (defined as three or more evoked action potentials). In rats injected with raclopride daily for 7-14 days, burst responses were seen in a larger proportion of cells (17%) and bursts of up to nine action potentials could be evoked. The results suggest that repeated administration of dopaminergic agents can induce striking plastic changes of excitatory responses in a subset of ventral striatal neurons.
Brain Research Institute, University of California, Los Angeles 90095-1761, USA.
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D000818:Animals; D018492:Dopamine Antagonists / Q000494:pharmacology*; D065127:Dopamine D2 Receptor Antagonists; D004594:Electrophysiology; D006624:Hippocampus / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D017072:Neostriatum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000502:physiology; D020891:Raclopride; D051381:Rats; D017207:Rats, Sprague-Dawley; D012457:Salicylamides / Q000494:pharmacology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D013788:Thalamus / Q000502:physiology
D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D012457:Salicylamides; D020891:Raclopride