Ondansetron cognition enhancer

Cognitive enhancing effects of 5-HT3 receptor antagonists have been observed in several animal models, using both normal animals and animals in which a cognitive deficit has been induced by the administration of the muscarinic antagonist scopolamine [41]. An example is the Wisconsin test, in which marmosets learn to discriminate which of two objects conceal a food reward and, after learning this, the task is reversed such that the food is hidden beneath the other object. Treatment with ondansetron has been shown to enhance the ability of marmosets to learn the reversal task. 

Aged rhesus monkeys were assessed in several cognitive and motor tasks, acquisition of a visual object discrimination, reversal of a visual object discrimination, a delayed response task, a spatial working memory task, and a fine motor task. The S-HTj receptor antagonists ondansetron and SEC-579 at very low oral doses selectively enhanced acquisition of a visual object discrimination task but not the reversal or delayed tasks [Arnsten et al. 1997]. 

In a study of age-associated memory impairment [Crook and Lakin 1991), using a double-blind, placebo-controlled trial and three doses of ondansetron (10, 250, or 1,000 pg po bid), patients were treated for 12 weeks, followed by a 2-week washout period, with assessments being made at the initiation of, during, and at the termination of treatment. Behavioral rating scales and a computerized battery of tests related to learning and memory tasks of daily life were used to assess changes in cognitive performance. Ondansetron caused dose-related effects to enhance acquisition, name-face associa-... 

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