Changes in behavior and monoamine levels in microdialysate from dorsal striatum after 6-OHDA infusions into ventral striatum.
Long-Evans rats received bilateral 6-hydroxydopamine infusions into the nucleus accumbens and were tested immediately (1 and 2 days) or after a recovery period (14 and 15 days) for changes in extracellular levels of dorsal striatal monoamines using in vivo microdialysis. Compared to controls, the monoamine metabolites 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid were generally enhanced when tested immediately after 6-hydroxydopamine treatment, including spontaneous levels and those following depolarizing infusions of potassium (60 mM, 20 min) through the microdialysis probes. Following 2 weeks recovery, dopamine metabolite levels were depressed and the serotonin metabolite levels remained enhanced. D-Amphetamine sulfate (1.5 mg/kg, SC) stimulated dopamine overflow was enhanced 2 days after 6-hydroxydopamine administration, but not after 2 weeks recovery. In contrast, potassium increased dopamine overflow to the same extent as control animals regardless of recovery period following 6-hydroxydopamine. The immediate changes in striatal monoamine activity were accompanied by a potentiation of amphetamine-induced stereotyped behaviors. We suggest that transient presynaptic changes within the dorsal striatum following disruption of the ventral striatum may mediate some general aspects of loss and recovery of behavior related to the time course of 6-hydroxydopamine neurotoxicity.
Tran-Nguyen
L T
LT
Department of Psychology, Arizona State University Tempe 85287-1104, USA.
Castañeda
E
E
MacBeth
T
T
D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015306:Biogenic Monoamines / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D007267:Injections; D008297:Male; D017551:Microdialysis; D009043:Motor Activity / Q000187:drug effects; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D016627:Oxidopamine / Q000008:administration & dosage / Q000494:pharmacology*; D011188:Potassium / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D013239:Stereotyped Behavior / Q000187:drug effects; D013565:Sympatholytics / Q000008:administration & dosage / Q000494:pharmacology*
D018759:Adrenergic Uptake Inhibitors; D015306:Biogenic Monoamines; D018765:Dopamine Uptake Inhibitors; D013565:Sympatholytics; D016627:Oxidopamine; D000661:Amphetamine; D011188:Potassium; D004298:Dopamine