Physiological and Ethological Effects of Caffeine, Theophylline, Cocaine and Atropine; Study Using the Ant Myrmica sabuleti (Hymenoptera, Formicidae) as A Biological Model

Aiming to check if ants can be used as biological models, we studied the effects of four alkaloids on the ant Myrmica sabuleti. Caffeine and theophylline increased the ants’ linear speed, decreased their precision of reaction and their food consumption, did not affect their response to pheromones, nor their audacity, largely increased their conditioning ability and their memory; ants did not become habituated to nor dependent on these alkaloids. The effects of caffeine exponentially decreased in the course of time; those of theophylline slowly decreased sigmoidally after a latency period. Cocaine decreased the ants’ linear speed, their precision of reaction, their response to pheromones and their consumption of food; it increased their audacity; under its consumption, ants became unable to acquire conditioning. Ants became habituated to and dependent on such an alkaloid. The effects of cocaine rapidly vanished in the course of time. Atropine did not affect the ants’ locomotion, decreased their precision of reaction and their response to pheromones because it reduced their olfactory perception; it did not affect their audacity, decreased their food consumption, increased the speed in acquiring conditioning but not the quality of the resulting conditioning; it slightly increased their memory. Ants did not become habituated to, nor dependent on this alkaloid. The effects of atropine vanished in about 20 hrs - 30 hrs. These effects are in agreement with those known by physiologists, psychologists and doctors in medicine; observations made on ants even lead to more precise deductions. Consequently, ants can efficiently be used as biological models.