SEMINARIO: Diego E. Hernández Trejo

Speaker: Diego E. Hernández Trejo
Cold Spring Harbor Laboratories

Title: Rapid updates of reward-expectancy signals to the olfactory bulb support fast multisensory-guided behavioral switching

Abstract: Animals adjust their behavior to adapt to relevant environmental changes, but the neural pathways enabling these changes remain unclear. Mice excel in discriminating odorants in complex sensory conditions. However, little is known about how changes in stimulus contingency affect odor representations during behavioral adjustments. The anterior piriform cortex (aPCx) sends dense feedback to the olfactory bulb (OB) and shapes olfactory sensory representations.
To investigate the role of aPCx-to-OB feedback in supporting flexible behaviors, I designed a novel Go/No-Go task with rule reversals guided by odorant and sound cues. Within the same session, stimulus-reward contingencies were reversed across blocks of trials, while I monitored the cortical feedback activity using multiphoton microscopy (GCaMP). The aPCx-feedback activity mirrors the reversals in stimulus-reward contingency. Within seconds of each rule reversal, individual boutons reshape their responses to the same sensory cue in tight correlation with the behavioral switch. Optogenetic suppression (Jaws) of cortical feedback in the OB decreases behavioral switching performance. Our results indicate that aPCx feedback to the OB: (1) multiplexes stimulus identity and reward contingency signals; (2) this information is rapidly reformatted in response to changes in reward expectancy; and (3) these changes in response are necessary to drive fast goal-directed behavioral switching.
In my future research program, I aim to exploit this novel Go/No-Go task with rule reversals to study the orbitofrontal cortex circuit mechanisms that support the learning and control of fast, goal-directed behavioral switching. Moreover, I aim to describe the orbitofrontal circuit dysfunctions underlying behavioral inflexibility in neurological conditions such as autism spectrum disorder, and design experimental interventions to prevent it.