Achievement

The responses of neurons in primary visual cortex (V1) can be selectively and significantly enhanced by pairing a brief visual stimulus with electrical microstimulation. IGERT student David Whitney and his advisor Justin Crowley at Carnegie Mellon University, who collaborate with Professor Fred Wolf in Gottingen, Germany, have shown that such evoked plasticity is not distributed uniformly across the cortex. The experiments involved two different imaging modalities: intrinsic signal optical imaging, which reveals neural activity across several millimeters of cortex, and two-photon calcium imaging, which shows single-cell responses. Whitney hypothesized that plasticity is dependent on the local geometric structure of the V1 orientation preference map. Using special analytical techniques he learned while visiting the Wolf lab, Whitney showed that plasticity was in fact greatest when local cortical activation was far from the "pinwheel" centers where many orientation preferences meet.