Joseph M. Martinez, PhD

The Wallace Lab studies how specific circuits within the basal ganglia guide motivated behaviors, control goal-oriented motor actions, and how these circuits are affected under stress or in disease conditions. The process of selecting an action, evaluating, and storing the outcome to inform future responses has long been known to require the basal ganglia and lateral habenula (LHb) though the exact role LHb plays in this process remains undefined. Dr. Martinez’s project addresses this knowledge gap by seeking to determine the mechanistic role genetically and anatomically defined neuronal subfields of the LHb play in action selection during both normal and stressed conditions. Previously, the Lab has defined genetically distinct neuronal subtypes within the LHb and has developed a variation of a 2-armed bandit behavioral task (2ABT). The 2ABT tests the ability of an animal to select an action to receive a reward from two choices using previously learned information. Using this task along with genetically targeted viral constructs for biosensors or gene knockout, Dr. Martinez can manipulate and observe LHb circuit dynamics in vivo in a behaving animal. Utilizing these tools, Dr. Martinez will test the hypotheses that distinct, genetically defined LHb neuronal subtypes encode the action, the outcome, or both to differentially control action selection behavior and that perturbed activity in LHb neuronal subtypes underlies stress induced alterations in action selection. We hypothesize that, at least partially, perturbed adrenergic signaling plays a role in this process and will seek to elucidate the role adrenergic signaling plays in the LHb in normal and stressed conditions using these same techniques. This project utilizes the techniques and skills present in the Wallace Lab while also leveraging my expertise in subcellular adrenergic signaling in both learning and stress.