[Effect of tryptophan and its metabolites on the conditioned reflex activity of the honeybee]

The effect of tryptophane and its derivatives on the rate of elaboration and transformation of conditioned reflexes (CR) to odour, with alimentary reinforcement, was studied in wild bees under two conditions: free movement of the bee or its immobilization (stress situation), by means of genetic models (mutations, successive blocking stages of kynurenin path of tryptophane metabolism). It was shown that mutations eliciting accumulation of free tryptophane and serotonin in the hemolymph of the bees and creating a deficit of kynurenins accelerate the transformation of conditioned reflexes and aggravate the depression of conditioned activity usually elicited in wild bees by monotonous prolonged presentation of conditioned signal. The injections of tryptophane and serotonin (5 mg) produce the same action. Mutations, eliciting accumulation in the hemolymph of the kynurenins (kynurenin and 3-hydroxikynurenin) accelerate, in conditions of immobilization, the formation of conditioned reflexes and delay the process of their transformation, and also contribute to maintainance of a higher (in comparison with the norm) level of the conditioned activity under monotonous presentation of the signal. The same action is produced by the injection of 1 mcg kynurenin.