[Modulation of the process of habituation by single-component solutions of agonists of opiate mu-, delta-, kappa- and sigma-receptors].

The modulating influence of such specific agonists of opiate mu-, delta-, kappa- and sigma-receptors as morphine, D-Ala2, D-Ley5-enkephaline (DADL), bremazocine, and SKF 10,047 as well as that of naloxone, their specific blockator, on habituation of orthodromic evoked potential in the visual cortical area was studied in turtles. In spite of equal degree of suppression of evoked potentials by the agonists used, their ability to modify habituation was different. Morphine, bremazocine and SKF 10,047 were of high effectivity while DADL was of low one.