Biology

Dr. Shonali Dhingra
Department of Physics & Astronomy, UCLA

Abstract:

While navigating the world, Hippocampus has been shown to play a significant role in keeping track of the space around us. Our work shows that hippocampal cells recognize space as a vector! These cells have been shown to keep track of the subject’s current absolute position in the form of Place Cells. Our work shows that hippocampal cells also keep track of the direction of rat’s position with respect to a frame of reference. We show that the these cells are capable of using various frames of reference to keep track of the rat’s current direction. These frames include infinitely far frames, thus keeping track of the canonical Head Direction. We also show that these cells utilize various frames of reference at finite distances from rat’s current position. We call the origin of these reference frames as Anchor Points. We see that these cells code for such anchor points in coherent and stable ways, and we call such tuning of these cells as Anchor Fields. We utilize various experimental manipulations to study the properties of these Anchor Fields. We observe that visual cues are capable of affecting various properties of these anchor tunings, including position of Anchor Points, size of Anchor Fields, percentage of cells tuned to these points, and changing the direction of tuning with respect to these anchor points. We posit that these tunings are utilized by the hippocampal cells to create a vectorial map of space in our brains.