Sandeep R. Datta
Reception and Neural Processing of Signals from the Environment
The goal of our laboratory is to address a core problem in neuroscience: how is the brain wired to extract information from the environment and convert that information into action? The main hypothesis of the laboratory is that we can gain leverage on this physiological problem (and the related problem of how diseases disrupt brain function) by studying neural circuits that underlie stimulus-driven innate behaviors. Given that olfaction is the primary sense used by most animals to communicate with their environment, we focus on characterizing those circuits that enable animals to detect and innately respond to scents from food, predators and mates. These circuits are highly constrained by evolution and exhibit stereotyped anatomic and genetic architectures, which significantly facilitates their experimental interrogation. Sensory information propagating through this hardwiring can drive complex behaviors (such as avoidance or sexual displays), alter neuroendocrine states and act as unconditioned stimuli to facilitate learning. We believe that tracing and manipulating the neural wiring that mediates odor-driven innate behaviors will reveal fundamental and general principles about how information is meaningfully encoded in the brain, how that information is coupled to behavioral centers, and how the circuits which convey that information can dynamically adapt to a changing world.
To structurally and functionally dissect olfactory circuits we deploy an interdisciplinary toolkit that includes both well-established techniques, such as mouse genetics and behavioral analysis, and emerging approaches, such as two-photon laser scanning microscopy, deep sequencing and optogenetics. We currently use these methods to identify specific monomolecular odorants that drive genetically-programmed behaviors, to define receptors for these odorants, and to characterize the functional architecture of the downstream neural circuits that translate the activation of a specific receptor in the nose into a particular behavioral response. These circuits traverse well-characterized peripheral structures, such as the olfactory epithelium and olfactory bulb, before triggering activity in less explored regions of the mammalian brain, including the piriform cortex, the cortical amygdala and olfactory tubercle. In addition to exploring how ethologically-relevant sensory information is encoded in these regions of the olfactory cortex, we are actively interested in how odor maps in these areas are read by output centers in the ventral striatum and hypothalamus, sites critical to the execution of innate behaviors, to learning and reward, and to the regulation of neuroendocrine status.