6-OHDA-treated weanling rats show normal neuroleptic sensitivity as adults on LHSS.
Weanling rats receiving 6-hydroxydopamine (6-OHDA) ICV on postnatal days 15-20 and tested as adults have normal lateral hypothalamic self-stimulation locus of rise (LOR) reward thresholds but significantly lower operant motor/performance (MAX) capacity when compared to vehicle-treated controls using the rate-frequency method. These results are comparable to those previously seen in adult rats treated with 6-OHDA on postnatal day 3. In a second test, day 15-20 6-OHDA treated rats were tested as adults with pimozide (0.125-1.0 mg/kg) and showed LOR shifts ranging from 0.06-0.32 log Hz and MAX shifts of 83-47% of baseline. These results were not significantly different at any dose when compared to day 15-20 vehicle-treated rats. This second result contrasts with the pimozide subsensitivity previously reported in day 3 6-OHDA treated rats and suggests that DA depletions made later in neonatal life may involve different forms of recovery than those seen with earlier dopamine depletions.
Sidhu
K S
KS
Department of Psychology, Northeastern University, Boston, MA 02115.
Stellar
J R
JR
Garity
D
D
Bruno
J P
JP
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004567:Electrodes, Implanted; D006719:Homovanillic Acid / Q000378:metabolism; D007026:Hypothalamic Area, Lateral / Q000502:physiology*; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D016627:Oxidopamine; D010868:Pimozide / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012653:Self Stimulation / Q000187:drug effects*; D013563:Sympathectomy, Chemical
D014150:Antipsychotic Agents; D015102:3,4-Dihydroxyphenylacetic Acid; D010868:Pimozide; D016627:Oxidopamine; D004298:Dopamine; D006719:Homovanillic Acid