Rats pretreated i.c. with 10 μg of PONE were administered d-amphetamine and the effect of the combination of these drug treatments on behavior and the formation of 3H-norepinephrine from 3H-tyrosine was measured. PONE pretreatment blocked the d-amphetamine-induced increase in exploratory activity but enhanced the production of d-amphetamine-induced stereotyped behaviors. PONE pretreatment caused a 43% decrease in brain norepinephrine (NE) levels and this effect was potentiated by d-amphetamine. The in vivo formation of 3H-NE was decreased in animals administered d-amphetamine alone or PONE + d-amphetamine. However, these groups differed in the following respects: (a) d-amphetamine decreased the rate of disappearance of 3H-NE formed from 3H-tyrosine while PONE + d-amphetamine enhanced disappearance; (b) d-amphetamine decreased the formation of 3H-3-methoxy-4-hydroxyphenylglycol (MOPEG) while PONE + d-amphetamine enhanced 3H-MOPEG formation; (c) d-amphetamine enhanced 3H-NE release but decreased 3H-NE synthesis in a tissue slice preparation but PONE + d-amphetamine only enhanced 3H-NE release. The relevance of these findings to the effect of PONE pretreatment on d-amphetamine-induced behavior is discussed.
Bibliographical noteFunding Information:
The authorsw ish to acknowledgeth e invaluables ecre-tarial assistancoef Miss BarbaraH alperina nd the technical assistancoef Mrs. BarbaraH itzemannT.h e work describeidn this manuscripwt as submittebdy RJH for partiafl ulf'fllment of the degreeo f Ph.D. This study was supportedin part by U.S.P.H.S. Grant MH-24036 and U.S. Army ResearchC on-tract DADA-17-73-C-3127H.H L is a recipienot f a National Instituteo f Mental Health ResearchS cientistD evelopment Award No. K2-DA-70554.
- Exploratory behavior
- Stereotyped behavior