Davi Drieskens Carvalho de Castro Sá Barreto

M.Sc.in neuroscience and behavior at the Federal University of Paraíba (2016). Ph.D. in progress in Neuroscience at Brain Institute (Federal University of Rio Grande do Norte; 2016 - 2020), studying how does brain signals correlates to animal behavior

Nervous systems evolved as mediators of a sensory-motor loop, orchestrating behavioral outputs as appropriate responses to the environmental conditions read by the senses. A fundamental goal of neuroscience is, thus, to understand how brain circuits work to sustain perception and organize behavior. Much progress has been made by recording brain activity in model animals performing structured and reproducible sensory-motor tasks. This approach allows the experimenter to perform statistical analysis of neuronal correlates under well-controlled conditions. This, however, comes at a cost, as both stimuli and behavior are restricted and forced out of the natural range under which brain function evolved. Modern recording and analysis techniques are driving a new wave of ethology, allowing the study of natural behaviors in freely moving animals under strict quantitative analysis. Our lab aims at contributing to the understanding of mammalian brain function by developing new approaches for the rigorous study of such behaviors together with distributed recordings of neuronal activity.

We are studying in this way vocal communication with rats as model animals. Rats produce vocalizations that span the frequency range from the sonic to the ultrasonic. Above 30 kHz, rats produce a rich repertoire of vocalizations spanning a wide range of frequency, modulation and duration. The role these calls play in social behavior is however largely unknown. We have developed methods to automatically record and analyze ultrasonic vocalizations from pairs of interacting rats and are now studying its structuring within and between rats. We are also simultaneously monitoring the behavior and physiology of emitters and receivers of these calls to understand their function.

Our quantitative study of vocalizations pointed us to the possible existence of global rhythms in the rat, involving both periodic motor rhythms and neuronal oscillations at similar rates. We are now developing methodologies to put this to the test by the combined recording of about a dozen motor and neuronal activities from freely behaving animals. We hope this approach will shed light on the evolution and function of neuronal oscillations in the brain.