Effects of a 5-HT2 receptor agonist and an antagonist on the behavior of rats with different choices of reinforcement value

The effects of the 5-HT2 receptor agonist DOI ((±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride) and the antagonist ketanserin (ketanserin tartrate salt) were studied in rats using the "right to choose" reinforcement value method. Depending on the preferred food reinforcement choice, the rats were divided into self-controlled (selecting the more valuable but delayed reinforcement) and impulsiv (preferring low-value but rapid reinforcement) groups. Animals received intraperitoneal DOI or ketanserin at a dose of 0.2 mg/kg 1 h before testing. Behavioral parameters were measured - the number of pressing of the two pedals, the latent periods of opening the screen and pressing the pedal, and the number of missed screen shifting/pedal pressing reactions. Administration of ketanserin produced a statistically significant increase in selection of the low-value, immediate reinforcement in the group of impulsive animals but did not alter the behavior of self-controlled animals. After administration of DOI, neither of the groups showed any statistically significant changes in reinforcement choice, though studies of the actions of this agent demonstrated statistically significant reductions in impulsivity in all animals, regardless of division into typological groups. In some cases, DOI decreased the number of missed reactions, while ketanserin decreased the latent period of responses. © 2014 Springer Science+Business Media.