Merck, Sharp & Dohme Prize for Young Psychopharmacologists: The pharmacology of saccadic eye movements.

Techniques allowing the accurate measurement of saccadic eye movements have been developed over the last 40 years. Originally, such measurements were used to assess or diagnose oculomotor pathology. With the discovery that saccadic eye movements were altered by drugs, especially those active at the GABA/ benzodiazepine receptor complex, these changes have been used as a measure of psychomotor performance. This has now become a major application of these techniques: to investigate pharmacodynamic activity, or to assess side-effects or interactions of drugs. There is now evidence that other receptor systems (e.g. a(2)-adrenoceptor, histamine, TRH) are also involved in the control of saccades. While it is still unclear whether drug-induced changes in saccadic eye movements are due to effects on pathways generating or controlling saccades or are secondary to changes in arousal, recent studies suggest that saccade and arousal changes may be distinguished under certain conditions. The most recent development in the use of saccadic eye movements has been to examine benzodiazepine receptor sensitivity in anxiety disorders or changes in receptor sensitivity after drug treatment. Drug-induced changes in saccadic eye movements appear to offer a direct, sensitive and minimally invasive means of investigating central receptor function in man.