Thinking about networks in the control of male hamster sexual behavior.

Motivated social behaviors such as mating are controlled by a complex network of limbic nuclei. Concepts of network organization derived from computational neuroscience may aid our understanding of the links between the neuroanatomical circuitry and what is represented by the anatomy. Research in my laboratory uses mating behavior in the male Syrian hamster as a model to elucidate how chemosensory and steroid cues are integrated in the brain. An interaction of odors and hormones is required for mating in this species. These two essential stimuli are transmitted through separate parallel pathways in the limbic system. The functional organization of the hamster mating behavior circuit is characterized by distributed representation, divergent and convergent neural pathways, and recurrent feedback. Odors and hormones have different modes of action on this neural network. While chemosensory cues stimulate the input units of the network, steroids facilitate behavior through the hidden units. In this manner, steroids appear to create a permissive environment for subsequent activation by odor cues.