Antagonism of skin conductance response (SCR) habituation during iterative photostimulation in mice: habituation test - a new psychopharmacological method for detecting and quantifying enhancement of psychic activity.

A method (habituation test) for studying habituation of the palmar skin conductance response (SCR) during iterative photostimulation in mice is described. Twenty drugs known for their CNS stimulant activity and/or beneficial action on learning were tested for their antagonism toward habituation. With most of the drugs tested, the delay in SCR extinction was dose-dependent. From the corresponding regression equations, the standard delaying doses were computed and used for classification. Fenozolone was the most active product. In descending order follow dexamphetamine and piracetam, then other amphetamines. Locomotor activity tests were run in parallel with habituation tests and the two sets of results compared. Reliability of habituation test was checked. The responsiveness of the test and the significance of the results are discussed. The applicability of the habituation test in psychopharmacological research is argued by its sensitivity to piracetam, whose nootropic activity is not detectable by classic behavioral methods. The habituation test makes it possible to test drugs for their effects on the maintenance of attention during monotonous stimulation and, more generally, for their psychic enhancement activity whatever the mechanism involved. It is thus likely to be a suitable test for nooanaleptics (in the broad meaning of the term).