Mesolimbic dopamine and its control of locomotor activity in rats: differences in pharmacology and light/dark periodicity between the olfactory tubercle and the nucleus accumbens

1986 ◽  
Vol 88 (4) ◽  
Author(s):  
A.R. Cools
1993 ◽  
Vol 71 (5-6) ◽  
pp. 407-413 ◽  
Author(s):  
Michael Wu ◽  
Stefan M. Brudzynski ◽  
Gordon J. Mogenson

The interaction of dopamine and glutamate in the nucleus accumbens in the regulation of locomotion was investigated. Microinjection of N-methyl-D-aspartic acid (NMDA, a glutamatergic NMDA receptor agonist) or α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA, a quisqualic receptor agonist which is a glutamatergic non-NMDA receptor agonist) into the nucleus accumbens caused a substantial increase in locomotor activity. This increase in locomotor activity was significantly reduced by prior administration of the dopamine D2 agonist quinpirole, but not the D1 agonist, SKF 38393, into the same brain sites. The reduction in locomotion produced by quinpirole was dose dependent. Eight days after the ventral tegmental area was lesioned with 6-hydroxydopamine to destroy the dopamine projection and the axon terminals of the mesolimbic dopamine neurons in nucleus accumbens, the hyperkinetic effects produced by injections of NMDA and AMPA into the nucleus accumbens were substantially reduced. These results suggested that the glutamate agonist induced locomotion is mediated by dopamine. Thus, it appears that NMDA- or AMPA-induced locomotion is due to the activation of glutamate receptors on the mesolimbic dopamine terminals in the nucleus accumbens which release dopamine and subsequently increase locomotion.Key words: nucleus accumbens, dopamine, glutamate, quinpirole, locomotion, N-methyl-D-aspartic acid, α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid.


1975 ◽  
Vol 41 (2) ◽  
pp. 87-95 ◽  
Author(s):  
A. J. J. Pijnenburg ◽  
W. M. M. Honig ◽  
J. M. Van Rossum

2020 ◽  
Author(s):  
William N. Sanchez ◽  
Jose A. Pochapski ◽  
Leticia F. Jessen ◽  
Marek Ellenberger ◽  
Rainer K. Schwarting ◽  
...  

AbstractBackground and PurposeCurrently, no effective drug exists to treat cocaine use disorders, which affect millions of people worldwide. Benzodiazepines are potential therapeutic candidates, as microdialysis and voltammetry studies have shown that they can decrease dopamine release in the nucleus accumbens of rodents. In addition, we have recently shown that diazepam blocks the increase in dopamine release and the affective marker 50-kHz ultrasonic vocalizations (USV) induced by DL-amphetamine in rats.Experimental ApproachHere we tested whether administration of 2.5 mg·kg−1 diazepam (i.p.) in adult male Wistar rats could block the effects of 20 mg·kg−1 cocaine (i.p.) on electrically evoked phasic dopamine release in the nucleus accumbens measured by fast-scan cyclic voltammetry, as well as 50-kHz USV and locomotor activity.Key ResultsCocaine injection increased evoked dopamine release up to 3-fold within 5 min and the increase was significantly higher than baseline for at least 90 min. The injection of diazepam 15 min later attenuated the cocaine effect by nearly 50% and this attenuation was maintained for at least 30 min. Stimulant drugs, natural rewards and reward predictive cues are known to evoke 50-kHz USV in adult rats. In the present study, cocaine increased the number of 50-kHz USV of the flat, step, trill, and mixed kinds by 12-fold. This effect was at maximum 5 min after cocaine injection, decreased with time and lasted at least 40 min. Diazepam significantly blocked this effect for the entire duration of the session. The distance travelled by control rats during a 40-min session of exploration in an open field was at maximum in the first 5 min and decayed progressively until the end of the session. Cocaine-treated rats travelled significantly longer distances when compared to the control group, while diazepam significantly attenuated cocaine-induced locomotion by up to 50%.Conclusions and implicationThese results suggest that the neurochemical, affective, and stimulant effects of cocaine can be mitigated by diazepam.What is already knownDiazepam decreases dopamine release in the rodent nucleus accumbens (NAc) and reduces some effects produced by DL-amphetamine.What this study addsDiazepam attenuated the increase in phasic dopamine release caused by cocaine.Diazepam blocked the effect of cocaine on 50-kHz USV and locomotor activity.Clinical significanceThis study demonstrates that diazepam can block specific effects of cocaine that likely contribute to addiction.


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