Psychophysical evaluation of toxic effects on sensory systems.

Toxic effects on sensory systems have rarely been evaluated by psychophysical methods. As examples of possible applications four studies are described. Sodium salicylate and kanamycin, both reported to produce hearing deficits in man, have also been demonstrated to affect auditory thresholds in monkeys. With the latter drug the deficits measured were found to be correlated with specific loss of receptor cells in the cochlea. Pheniprazine, known to induce red-green color blindness, was found to disrupt a wavelength discrimination in pigeons. Trans 11-amino-10,11-dihydro-5-(3-dimethylaminopropyl)-5,10-expoxy-5H-dibenzo[a,d]-cycloheptene dihydrochloride, which was found to bleach the tapidum lucidum in dogs when given subacutely, was found to decrease sensitivity to light. The loss in sensitivity measured by behavioral techniques was correlated with the loss of coloration of the tapidum. Monkeys, not having a tapidum, did not show a similar effect.