Office: 210-567-0106
Email: gerak@uthscsa.edu
Current research projects include studies on the behavioral pharmacology of compounds that modulate the γ-aminobutyric acid A (GABAA) receptor complex with an emphasis on the effects of ethanol and neuroactive steroids. GABAA modulators can vary in efficacy and selectivity for the various modulatory sites on the GABAA receptor complex as well as for different subtypes of GABAA receptors. Differences in the behavioral effects of GABAA modulators are assessed using procedures that examine acute (discriminative stimulus effects) and chronic (tolerance, dependence, withdrawal) effects of drugs. The general goals of this research program are: to develop quantitative methods for assessing the effects of chronic treatment with GABAA modulators; to evaluate fundamental differences in the behavioral effects of drugs that act at different modulatory sites on GABAA receptors; to understand dependence-induced changes in GABAA receptor function; to determine whether novel GABAA modulators might be useful pharmacotherapies for ethanol abuse; and to assess the applicability of receptor theory for interpreting behavioral effects of GABAA modulators.
Selected Publications
Gerak, L.R. and France, C.P. (2007) Time-dependent decreases in apparent pA2 values for naltrexone studied in combination with morphine in rhesus monkeys. Psychopharmacology, epub ahead of print.
Leonard, S.T., Gerak, L.R., Gurkovskaya, O., Moerschbaecher, J.M., and Winsauer, P.J. (2006) Effects of gamma-hydroxybutyric acid and flunitrazepam on ethanol intake in male rats. Pharmacology, Biochemistry and Behavior, 85:780-786.
Quinton, M.S., Gerak, L.R., Moerschbaecher, J.M. and Winsauer, P.J. (2006) Effects of pregnanolone in rats discriminating cocaine. Pharmacology, Biochemistry and Behavior, 85:385-392.
McMahon, L.R., Gerak, L.R. and France, C.P. (2006) Efficacy and the discriminative stimulus effects of negative GABAA modulators, or inverse agonists, in diazepam-treated rhesus monkeys. Journal of Pharmacology and Experimental Therapeutics, 318:907-913.
Quinton, M.S., Gerak, L.R., Moerschbaecher, J.M. and Winsauer, P.J. (2005) Interaction of cocaine with positive GABA(A) modulators on the repeated acquisition and performance of response chains in rats. Psychopharmacology, 181:217-226.
Gerak, L.R., Hicks, A.R., Winsauer, P.J., and Varner, K.J. (2004) Interaction between 1,4-butanediol and ethanol on operant responding and the cardiovascular system. European Journal of Pharmacology, 506:75-82.
Gerak, L.R., Stevenson, M.W., Winsauer, P.J., and Moerschbaecher, J.M. (2004) Effects of pregnanolone alone an in combination with other positive GABAA modulators on complex behavior in rats. Psychopharmacology, 173:195-202.
Gerak, L.R., Gauthier, C.A., and France, C.P. (2003) Discriminative stimulus and antinociceptive effects of dihydroetorphine in rhesus monkeys. Psychopharmacology, 166:351-359.
McMahon, L.R., Gerak, L.R., Carter, L., Ma, C., Cook, J.M., and France, C.P. (2002) Discriminative stimulus effects of benzodiazepine (BZ)1 receptor-selective ligands in rhesus monkeys. Journal of Pharmacology and Experimental Therapeutics, 300:505-512.
McMahon, L.R., Gerak, L.R., and France, C.P. (2001) Potency of positive γ-aminobutyric acid Amodulators to substitute for a midazolam discriminative stimulus in untreated monkeys does not predict potency to attenuate a flumazenil discriminative stimulus in diazepam-treated monkeys. Journal of Pharmacology and Experimental Therapeutics, 298:1227-1235.
Gerak, L.R., France, C.P., Woolverton, W.L., Nader, M.A., Patrick, G.A., Harris, L.S., Winger, G. and Woods, J.H. (2001) Behavioral effects of flunitrazepam: reinforcing and discriminative stimulus effects in rhesus monkeys and prevention of withdrawal signs in pentobarbital-dependent rats. Drug and Alcohol Dependence, 63:39-49.
Lelas, S., Gerak. L.R., and France, C.P. (2000) Antagonism of the discriminative stimulus effects of positive γ-aminobutyric acid A modulators in rhesus monkeys discriminating midazolam. Journal of Pharmacology and Experimental Therapeutics, 294:902-908.
Gerak, L.R. and France, C.P. (1999) Discriminative stimulus effects of flumazenil in untreated and diazepam-treated rhesus monkeys. Psychopharmacology, 146:252-261.
Gerak, L.R., Moerschbaecher, J.M., Bagley, J.R., Brockunier, L.L., and France, C.P. (1999) Effects of a novel fentanyl derivative on drug discrimination and learning in rhesus monkeys. Pharmacology, Biochemistry and Behavior, 64:367-376.
Woolverton, W.L., Rowlett, J.K., Winger, G., Woods, J.H., Gerak, L.R., and France, C.P. (1999) Evaluation of the reinforcing and discriminative stimulus effects of γ-hydroxybutyrate in rhesus monkeys. Drug and Alcohol Dependence, 54:137-143.
Lelas, S., Gerak, L.R., and France, C.P. (1999) Discriminative-stimulus effects of triazolam and midazolam in rhesus monkeys. Behavioural Pharmacology, 10:39-50.
