Effect of tryptophan and its metabolites on conditioned reflex activity of the honey bee.

Abstract

1. The snow and snowIaranja mutations, causing accumulation of free tryptophan and serotonin and a deficiency in kynurenins, accelerate the process of alteration of conditioned alimentary reflexes to olfactory signals. A similar action is exerted on injection of tryptophan and serotonin at a dose of 5 μgrams into wild type bees. 2. The ivoryumber and brick mutations, causing accumulation of kynurenin and 3-hydroxykynurenin, respectively, accelerate the formation of conditioned reflexes and prolong the process of their alteration in the case of immobilized bees. A similar action is exerted by an injection of 1 μgram kynurenin into wild type bees. 3. The snowIaranja mutation intensifies the inhibition of the conditioned reflex activity induced normally in wild type bees by monotonous presentation of a conditioned signal. A similar action is exerted by injecting tryptophan at a dose of 5 μgrams into wild type bees. 4. The ivoryumber mutation promotes the maintenance of a higher level of a conditioned reflex activity compared to the normal, on monotonous presentation of a conditioned signal. A similar action is exerted by an injection of 1 μgram kynurenin into wild type bees.