Presenter(s): Emmalyn Leonard—Biochemistry
Faculty Mentor(s): Cristopher Niell, Philip Parker
Session 5: The Wonders of the Brain
Visual attentional control is a behavior that is critical for survival; despite its importance, the specific neural mechanisms underlying the process remain unclear . Upon perception, visual information is routed from the retina through the thalamus, which relays signals to the cortex for further processing . The pulvinar, a nucleus of the thalamus, has strong connections to both visual cortex (V1) and areas involved with attentional control, such as the superior colliculus and prefrontal cortex . The pulvinar has been implicated in attentional control from studies of human patients, as pulvinar lesions are correlated with an inability to ignore distracting visual information during performance of a behavioral task . Studies have also shown that mice are capable of learning similar tasks; given that their visual system is highly analogous to that of humans, mice serve as an optimal model for important behaviors such as visual attentional control . We targeted mouse pulvinar neurons with a GCaMP-expressing virus to allow measurement of brain activity through a cranial window . Utilizing both widefield and two-photon microscopic imaging, we found that axons projecting from the pulvinar to V1 are visually responsive and appear to be organized in a retinotopic manner . Future work on this project will include introduction of a visually guided behavioral task alongside silencing of pulvinar neurons using a DREADDs-expressing virus . We expect to find that, when mouse pulvinar neurons are silenced, important signals for visual attention sent from the thalamus to V1 will be interrupted, resulting in poor performance of a task requiring visual attentional control .