[The effect of different types of species-specific acoustic signals on the rate of mammalian cardiac contractions].

Experiments with rodents and even-toed ungulates show that significant changes in the heart rate (HR) in response to administration of species-specific sound stimuli occur only under conditions of deficiency of useful information. Cardiac response depends mainly upon the type of the signal, ecology and physiology of the animal-recipient. In mammals living in colonies and herds in the open (ground squirrels, reindeer) HR changes become conspicuous only under conditions excluding acquirement of visual information. Active escape conditioning by one of the species-specific signals in Arctic ground squirrels at the stage of habituation leads to selective decrease of intensity and probability of cardiac response to conditioned stimulus and any other type of alarm signal (whistling). Experiments with HR recording in albino rats show that biological dominant of maternal breeding as compared to other species-specific signals selectively influences degree of emotional discomfort in pups.