research basics lab members publications links contact  




 

This “spatial” model of odor identity is clearly an oversimplification: it does not account for the fact that the neurons that detect and process odors send electrical pulses forward to the brain at different rates and with different patterns, and there is evidence that the brain also uses this “temporal” information to identify odorants. But it has provided the most comprehensive framework thus far for understanding how the brain organizes information about smells, and it raises a crucial question: how is the odor map in the olfactory bulb read by the rest of the brain to enable us to perceive odors and generate appropriate behaviors?

The goal of our lab is to understand how an odor stimulus in the environment is coupled to neural machines in the higher brain to generate specific behaviors. Our core hypothesis is that we can understand this process by characterizing the neural wiring that runs from the nose through the bulb into the higher brain that is dedicated to sensing odors that are particularly important to mice — such as those from food, predators and mates. One significant advantage of studying perception from this perspective of innate behaviors arises from the nature of the underlying circuits: because innate behaviors are hardwired into the brain by genes, we can use the genes that build these neural circuits as tools to better understand how the brain works.  Another advantage of studying odor-driven innate behaviors is that the relevant odors, in many cases, may be detected by a small number of “specialist” odorant receptors in the nose, potentially simplifying our problem from having to understand how the brain processes an odor map with 1000 channels of information coming from the olfactory bulb to having to understand an odor map with just a handful of relevant channels.

Our lab uses techniques ranging from passively observing the behavior of animals as we offer them odors to actively controlling the behavior of genetically-modified animals by remotely triggering activity in specific parts of their brain; by combining many different approaches to characterizing the nervous system we hope to link specific odors to specific neural circuits and to understand how electrical activity propagating through those neural circuits generates innate behaviors. We also believe that our effort to map the neural circuits that underlie innate behaviors will be relevant to understanding how the nervous system solves more complex problems. For example, while innate behaviors are hardwired into the brain by genes during development, they are not fixed forever — with training, adult animals can learn to modify their innate behavioral responses to odorants. Observations such as these suggest that we can (somewhat paradoxically) discover principles about how our brain learns to adapt to changes in the environment by characterizing hardwired neural circuits. And finally there are many neural and psychiatric diseases — ranging from anorexia nervosa to panic disorder — that sit at the interface between perception and behavior. It is our hope that better understanding how the brain couples stimuli to action may lead to improved approaches to treating these disorders.

< previous