Dr. Genela Morris , Department of Neurobiology, University of Haifa
Room 1061, Mayer building, Electrical Engineering, Technion at 16:00
22 March, 2011
Sculpting the hippocampal cognitive map: experimental control over the coded parameter space
Although much work in the field of reinforcement learning has been devoted to understanding how animals and humans learn to perform the best action in each state of affairs, strikingly scant work targets the question of what constitutes such a state. In initial phases of learning, an animal or a person cannot know which facets of its rich experience should be attended to in order to identify their ‘state’. In a number of projects, we use tasks in which several different attributes can potentially be important for procuring rewards (odors, spatial location, previous actions), and specifically investigate the behavioral and neural processes underlying learning of which is the relevant state. This talk will focus on parameter coding by hippocampal primary neurons.
The hippocampus serves an important role in learning and memory. In humans, it is associated with declarative episodic memory. Single unit recordings of hippocampal neurons in freely behaving rats have shown that many of them act as place-cells, confining their firing to well-defined locations in space. We recorded the activity of hippocampal primary neurons in a specially devised olfactory space, in which rats foraged for reward based solely on olfactory cues and studied the dependence of the activity of these neurons on their availability. We show that place cells shifted their firing fields from room coordinates to olfactory coordinates as animals learned to rely on them in order to obtain reward.