RATIONALE: C57BL/6ByJ (6ByJ) and C57BL/6J (6J) mice differ in their sensitivity to cocaine-induced convulsions, with CD(50) values being 100 and 70 mg/kg, respectively. This genetic sensitivity to cocaine-induced convulsions is probably related to 5-HT(2) receptors, since the density of these sites and the concentration of 5-HT(2) antagonists required to block cocaine-induced convulsions is lower in 6J mice relative to 6ByJ mice. OBJECTIVE: Although 5-HT(2) receptors appear to play a role in mediating genetic sensitivity to cocaine-induced convulsions, the role of 5-HT(2) receptor subtypes in this effect of cocaine has not been examined. METHODS: The present study compared the effects of the preferential 5-HT(2C) agonists m-chlorophenylpiperazine (mCPP) and 6-chloro-2-(1-piperazinyl)pyrazine (MK212) on cocaine-induced convulsions in 6ByJ and 6J mice. General activity was also measured following pretreatment with mCPP and MK212. RESULTS: Both mCPP and MK212 potentiated cocaine-induced convulsions and the effect of these agonists was more robust in 6ByJ mice relative to 6J mice. CONCLUSION: The findings from this study support previous research suggesting that 5-HT(2) receptors play a role in mediating cocaine-induced convulsions, and extend previous research by suggesting that the 5-HT(2C) receptor subtype mediates cocaine-induced convulsions and genetic sensitivity to this toxic effect of cocaine.
RATIONALE: C57BL/6ByJ (6ByJ) and C57BL/6J (6J) mice differ in their sensitivity to cocaine-induced convulsions, with CD(50) values being 100 and 70 mg/kg, respectively. This genetic sensitivity to cocaine-induced convulsions is probably related to 5-HT(2) receptors, since the density of these sites and the concentration of 5-HT(2) antagonists required to block cocaine-induced convulsions is lower in 6J mice relative to 6ByJ mice. OBJECTIVE: Although 5-HT(2) receptors appear to play a role in mediating genetic sensitivity to cocaine-induced convulsions, the role of 5-HT(2) receptor subtypes in this effect of cocaine has not been examined. METHODS: The present study compared the effects of the preferential 5-HT(2C) agonists m-chlorophenylpiperazine (mCPP) and 6-chloro-2-(1-piperazinyl)pyrazine (MK212) on cocaine-induced convulsions in 6ByJ and 6J mice. General activity was also measured following pretreatment with mCPP and MK212. RESULTS: Both mCPP and MK212 potentiated cocaine-induced convulsions and the effect of these agonists was more robust in 6ByJ mice relative to 6J mice. CONCLUSION: The findings from this study support previous research suggesting that 5-HT(2) receptors play a role in mediating cocaine-induced convulsions, and extend previous research by suggesting that the 5-HT(2C) receptor subtype mediates cocaine-induced convulsions and genetic sensitivity to this toxic effect of cocaine.
Authors: Meriem Gaval-Cruz; Jason P Schroeder; L Cameron Liles; Martin A Javors; David Weinshenker Journal: Pharmacol Biochem Behav Date: 2008-02-12 Impact factor: 3.533