| Abstract: | Morphine, added to the extracellular solution in a concentration of 1·10–5 M, quickly and reversibly weakens the depolarizing and hyperpolarizing responses of neurons of the snailHelix lucorum evoked by 1·10–6 M serotonin. The inhibitory effect of morphine is completely abolished by the addition of naloxone (1·10–5 M), suggesting that opiate receptors are involved in the process. Interaction between morphine and serotonin is noncompetitive in type, as is shown by the character of the dose-effect curves recorded during the action of serotonin before and after morphine application.Institute of Psychiatry, Academy of Medical Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 13, No. 6, pp. 589–593, November–December, 1981. |
