Effects of 5-HT1B receptor ligands microinjected into the accumbal shell or core on the cocaine-induced locomotor hyperactivity in rats
Przegalinski E, Filip M, Papla I, Czepiel K.
Department of Pharmacology,
Institute of Pharmacology,
Polish Academy of Sciences, Krakow.
J Physiol Pharmacol 2002 Sep;53(3):383-94
ABSTRACTThe present study was designed to examine the effect of 5-HT1B receptor ligands microinjected into the subregions of the nucleus accumbens (the shell and the core) on the locomotor hyperactivity induced by cocaine in rats. Male Wistar rats were implanted bilaterally with cannulae into the accumbens shell or core, and then were locally injected with GR 55562 (an antagonist of 5-HT1B receptors) or CP 93129 (an agonist of 5-HT1B receptors). Given alone to any accumbal subregion, GR 55562 (0.1-10 microg/side) or CP 93129 (0.1-10 microg/side) did not change basal locomotor activity. Systemic cocaine (10 mg/kg) significantly increased the locomotor activity of rats. GR 55562 (0.1-10 microg/side), administered intra-accumbens shell prior to cocaine, dose-dependently attenuated the psychostimulant-induced locomotor hyperactivity. Such attenuation was not found in animals which had been injected with GR 55562 into the accumbens core. When injected into the accumbens shell (but not the core) before cocaine, CP 93129 (0.1-10 microg/side) enhanced the locomotor response to cocaine; the maximum effect being observed after 10 microg/side of the agonist. The later enhancement was attenuated after intra-accumbens shell treatment with GR 55562 (1 microg/side). Our findings indicate that cocaine induced hyperlocomotion is modified by 5-HT1B receptor ligands microinjected into the accumbens shell, but not core, this modification consisting in inhibitory and facilitatory effects of the 5-HT1B receptor antagonist (GR 55562) and agonist (CP 93129), respectively. In other words, the present results suggest that the accumbal shell 5-HT1B receptors play a permissive role in the behavioural response to the psychostimulant.5-HT1b
The coke-craving brain
Cocaine and depression
Cocaine and the lonely rat
Monoamines, cocaine and rats
01 02 03 04 05 06 07 08 09 10 11 12
13 14 15 16 17 18 19 20 21 22 23 24
The Hedonistic Imperative
When Is It Best to Take Crack Cocaine?
The Good Drug Guide
The Responsible Parent's Guide To
Healthy Mood Boosters For All The Family