Pharmacopsychiatry 2003; 36 - 19
DOI: 10.1055/s-2003-825270

Kindling alters rewarding effects of ethanol, morphine and cocaine

A Becker 1, M Schmitz 1, G Grecksch 1
  • 1Institute of Pharmacology and Toxicology, Medical Faculty, Otto-v.-Guericke University Magdeburg, Germany

Brailowsky and Garcia (1999) proposed the existence of a relationship between epilepsy and addiction. It was speculated that the link of this relationship is γ-aminobutyric acid. GABAergic disinhibition is considered to be one of the mechanisms underlying epilepsy. Moreover, GABAergic interneurones possess inhibition of mesolimbic dopaminergic neurones which are involved in reward circuits. To elucidate interactions between epilepsy and addiction rewarding effects of ethanol, morphine, and cocaine were tested in the model conditioned place preference (CPP) using kindled rats. Moreover, effects of these drugs on locomotor activity and body temperature were measured.

In the CPP experiment, control rats dose-dependently preferred the arm of the apparatus associated with morphine and cocaine, respectively. In contrast, ethanol induced aversive effects. Interestingly, kindled animals did not develop either preference or aversion. There were no differences between kindled and control rats in locomotor activity and body temperature after substance application. This suggests that epileptic stimulation selectively affects reward mechanisms.

Brailowsky, S. and Garcia, O. Arch Med Res 30 (1999) 3–9