Joseph S. Lonstein

 lonstein@msu.edu

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Research Interests

The general focus of research in the lab is to understand behavioral changes that occur between pregnancy and lactation in animals. Non-lactating females of most species do not readily show nurturant responses to infants, although a dramatic change in responding occurs in females’ behavior after they are pregnant and their infants are born. One area of our research is devoted to understanding how the hormones of pregnancy and lactation alter neurochemistry in the rat brain to promote nurturant behaviors towards pups. We are currently focusing how release of the neurotransmitter dopamine within the preoptic area, a site important for some maternal behaviors, influences how mothers respond to their pups. This is being determined by measuring dopaminergic activity within the preoptic area during different stages of pregnancy and lactation, examining the dopaminergic projections to the preoptic area with neuroanatomical tracing methods, and pharmacologically manipulating dopaminergic activity in the preoptic area of virgin and lactating rats and observing changes in their maternal behavior.

A second area of research in the lab is devoted to the understanding of how emotional behaviors are regulated during lactation. Many rodents show reduced fear and anxiety after birth of the offspring, which may be important for their ability to act maternally towards the novel and potentially anxiety-provoking pups. We measure activity in the elevated plus-maze and freezing in response to acoustic startle as indices of anxiety and fear, and are currently examining how release of ovarian and pituitary hormones during lactation influence maternal emotionality, how sensory cues from pups (such as suckling) mediate the dam’s fear and anxiety, and what neural sites are important for reduced fear and anxiety during lactation.

Lastly, we are interested in how sex differences in the prairie vole brain contirbutes to their biparental and other monogamous behaviors. We find unique, species-specific sex differences in hypothalamic and extended amygdalar dopamine systems, and investigate how these contribute to the complex social behaviors displayed by members of this species.

Adequate and appropriate maternal responding is critical for the normal development, if not survival, of offspring. Our work on understanding the maternal brain, therefore, has clear implications for non-human development as well as for human welfare.

Please feel free to contact me if you have any questions about my research.

Selected Publications

Search all publications in the NCBI Journal Database

Northcutt, K.V, Wang, Z. & Lonstein, J.S. (2006).  Sex and species differences in tyrosine hydroxylase-synthesizing cells of the rodent extended amygdala.  Journal of Comparative Neurology, in press.