Marcelo Febo

Northeastern University, USA

Abstract

[O24] Imaging neuropeptidergic function in the maternal brain

Marcelo Febo¹, Martha K. Caffrey¹, Benjamin C. Nephew¹, Jessica Shields², Jean A. King² and Craig F. Ferris¹; ¹Center for Translational Imaging and Department of Psychology, Northeastern University, Boston, MA USA; ²Center for Comparative Neuroimaging and Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA USA

Lactating rats must continuously care for pups while aggressively protecting them against threats. The neuropeptides, oxytocin and vasopressin, contribute to postpartum behaviors such as lactation, reduced anxiety and aggression through actions in key limbic sites and therefore may help to maintain this critical balance. Recent studies using blood oxygenation level dependent (BOLD) MRI in awake rats have provided a window into the maternal brain that has allowed the study of the effects of these neuropeptides in lactation circuits, anxiety and aggression. In study 1, we used BOLD MRI to determine if oxytocin modulates brain activity in postpartum dams receiving suckling stimulation. Dams were exposed to pup suckling before and after administration of an oxytocin receptor antagonist. The data suggested that oxytocin may strengthen mother-infant bond formation partly by acting through brain areas involved in regulating olfactory discrimination, emotions and reward. In a follow up experiment, we tested whether pretreatment with oxytocin alters maternal brain activation in response to a predator scent. The observed pattern of brain activity suggests that oxytocin enhances neural processing in emotion and cognition driven brain areas such as the cingulate cortex, while dramatically reducing activity in areas also controlling autonomic, visceromotor and skeletomotor responses. Finally, we investigated whether V1a vasopressin receptors modulate maternal neural processing when dams are exposed to a male intruder threat to pups. Rats were given an injection of vehicle or V1a receptor antagonist before imaging.  During fMRI, awake dams were presented with a male intruder threat to pups using a specialized chamber that contained separate compartments for pups and a male intruder. It was concluded that vasopressin, acting through V1a receptors, may modulate sensory processing and perhaps coordinate this effect with changes in visceromotor activity during the initial stages of maternal aggressive motivation and/or anxiogenic responses.

Keywords: Oxytocin, Vasopressin, V1a Receptors, Oxytocin Receptors

Biography

Marcelo Febo is an Assistant Professor of the Department of Psychology at Northeastern University in Boston. He obtained his Ph.D. in Physiology at the University of Puerto Rico Medical Sciences Campus in Rio Piedras, Puerto Rico. His current research employs fMRI to investigate the consequences of repeated drug abuse administration on changes in brain function and behavior.