Iontophoretic evidence for subsensitivity of postsynaptic dopamine receptors following long-term amphetamine administration.
Neuronal activity was recorded from the anteromedial neostriatum of rats pretreated twice daily for 6 consecutive days with saline or 5.0 mg/kg d-amphetamine. Glutamate was applied in both groups of animals to increase spontaneous firing rates. Iontophoretic application of increasing currents of DA (20-120 nA) produced a progressive inhibition of unit activity in control animals that was significantly reduced in rats pretreated with amphetamine. These results support the view that long-term amphetamine treatment reduces the sensitivity of postsynaptic DA receptors in the neostriatum.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D002421:Caudate Nucleus / Q000187:drug effects; D003913:Dextroamphetamine / Q000494:pharmacology*; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D007478:Iontophoresis; D008297:Male; D011699:Putamen / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects; D013997:Time Factors
D005971:Glutamates; D011954:Receptors, Dopamine; D018698:Glutamic Acid; D001058:Apomorphine; D003913:Dextroamphetamine