Catherine Dulac, PhD
Samuel W. Morris University Professor, Harvard University
Investigator, Howard Hughes Medical Institute
Peering Into the Social Brain

Our group is using molecular, genetic and electrophysiological techniques to explore the molecular and neuronal basis of innate social behaviors in the mouse. Two major lines of research are currently being pursued in the laboratory:

We are pursuing several projects at the molecular, cellular and systems levels in order to investigate the architecture and functional logic of neuronal circuits underlying social behaviors. The key questions we are addressing are: What are the sensory signals that trigger specific social behaviors? What are the brain areas involved in processing these signals and generating species- and sex-specific behaviors such as aggression, mating, parental behavior, defensive behavior? What is the molecular identity of the neurons involved, how are they connected to each other, and how are they modulated by the animal physiological state and its previous social experience? And finally, how do circuits underlying sex-specific behaviors differ in the male and female brains?

The second set of projects explores the phenomenon of genomic imprinting in the brain, and the role of this mode of epigenetic modification in brain development and adult brain function. Genomic imprinting results in preferential expression of the paternally, or the maternally inherited allele of certain genes. We have recently used a genome-wide approach to characterize the repertoire of imprinted genes in the mouse embryonic and adult CNS. Our study uncovered a large number of new loci with imprinted features, suggesting that imprinting is a major mode of epigenetic regulation in the brain. Imprinting appears to preferentially affect neural systems associated with social, motivational and homeostatic brain functions. Comparison of the imprinted gene repertoire in the adult hypothalamus and cortex, and in the developing brain demonstrates a complex spatiotemporal, species-, sex- and isoform-specific regulation. Genomic imprinting thus emerges as a major and dynamic mode of epigenetic regulation of brain function, with direct implications for the understanding of evolution and diseases. Future projects in the lab will aim at better understanding this mode of epigenetic regulation in mechanistic and functional terms.