Erowid References Database
Minnema D, Rosecrans JA.
“Alterations Of The Discriminative Stimulus Produced By D-amphetamine Or LSD In Rats Neonatally Depleted Of Serotonin Or Dopamine”.
At three days of age rats were selectively depleted of brain serotonin (5-HT) (desipramine, i.p.. 5,7-dihydroxy tryptamine, i.c.). Neurochemical analysis was employed at the end of the experiment to determine the extent of the 5-HT depletion. At seventy days of age these rats, and cutaneous controls (desipramine i.p. only), were divided into two groups. one group was trained to discriminate the CNS cue (discriminative stimulus, DS) produced by LSD-tartrate (96 mcg/kg) from vehicle using the two-lever drug discrimination paradigm. Similarly, another group of rats were trained to discriminate the DS produced by d-amphetamine (d-A) from vehicle. Acquisition of both drug DS-tasks was similar for control and 5-HT-depleted rats. No significant difference between control and 5-HT-depleted rats was observed with respect to the dose-dependency of either DS. Similarly, no differences between control and 5-HT depleted were observed when the DS was antagonized (LSD: BC105; d-A: trifluoperazine). These data suggest that presynaptic 5-HT-processes do not play a major role l in the DS produced by either LSD or d-amphetamine. In an analogous study, another group of rats were depleted of brain dopamine at 14 days of age (desipramine, i.p.; 6-hydroxydopamine, i.c.). No difference between these rats and cutaneous controls (desipramine i.p. only) was noted with respect to the acquisition of either an LSD or drug discrimination task. However, the dopamine-depleted rats appeared to be less sensitive to the d-A DS, as indicated by a significant shift to the right in the d-A dose-response curve. Depletion of dopamine resulted in increased sensitivity of those rats trained to discriminate the LSD DS, as indicated by a significant shift of the LSD dose-response curve to the left. These results suggest that the dopaminergic system plays an important role in the DS produced by either LSD or d-A.
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