Investigating the role of the claustrum in social memory

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Social interaction is an important facet of human and animal existence. However, we currently know very little about the cellular mechanisms in the brain that support social information processing. The overall goal of my lab is to understand the neural circuitry underlying social memory. As mice are social animals they provide the ideal system for deciphering how the brain encodes, stores, and recalls social information Mice models provide the ability to record neural activity and behavior with exceptional temporal resolution during social behaviors, and the ability to precisely manipulate neural activity in a cell type, or pathway specific manner using state of the art molecular tools. There is a general understanding that social cognition relies on a set of brain networks which include the prefrontal cortex, the amygdala, and areas of the temporal lobe such as the hippocampus. More recent work using an unbiased, brain-wide screen, suggests that other regions within the ventral-lateral portion of the brain are activated by social stimuli. This work, together with our own findings, have converged upon a small structure with strong responses to social stimuli, and importantly, with exceptional dense connectivity with other brain regions known to also be activated by the same social cues. This structure is referred to as the claustrum (CLA). The CLA is interesting in its own right, as researchers have speculated about its function for decades. Francis Crick suggested that the CLA may be the center of consciousness in the brain, due to its extensive wide ranging connectivity. However, the CLA is incredibly hard to study due to its small size. We have developed a method to specifically record and manipulate CLA activity, and using these tools, the current proposal seeks to understand how the CLA functions in the context of social memory. The following proposal consists of three main goals. First, we will determine the anatomical pathways connecting the CLA to areas of the the social brain' and determine how these regions interact, and which pathways are especially active during social information processing. Second, we will use state of the art in vivo calcium imaging in freely moving mice, in order to measure CLA activity during social memory tasks. Finally using cell type and pathway specific optogenetic experiments we will determine the physiological mechanisms underlying how the CLA communicates with other brain regions such as the prefrontal cortex and determine any causal role of this structure in social behavior. Impairments in social information processing arise in disease states such as Alzheimer's disease and Autism spectrum disorder both of which are on the rise in Canada and other developed countries. Therefore, basic knowledge of how the social brain' operates, is central to the ability to understand and treat these disorders.