Tracking the information flow in the entorhinal hippocampal network

Research Group

Sachin Deshmukh and Supratim Ray and Govindan Rangarajan

Center for Neuroscience, IISc and Center for Neuroscience, IISc and Department of Mathematics, IISc

The entorhinal-hippocampal network shows a range of representations of space, in the form of place cells in the hippocampus, graph-paper like grid cells in the medial entorhinal cortex (MEC) and landmark-derived place cells in the lateral entorhinal cortex (LEC). Anatomical connectivity patterns indicate that the composition of information flowing from LEC and MEC to the hippocampus might be different, and depending on the sensory inputs available and behavioural state of the animal, the direction of information flow might change. For example, LEC is the primary target of olfactory information while MEC is the primary target of visual information. While both kinds of sensory stimuli are typically present simultaneously in a given environment, depending on whether the olfactory or the visual stimuli are relevant to the task at hand, LEC or MEC would exert control on hippocampal representation. In order to test these conditional changes in information flow patterns, we will record simultaneously from these three regions from rats using either olfactory cues (expected to be LEC dependent) or visual cues (expected to be MEC dependent) to perform a discrimination task in a continuous T-maze. We will use single unit and LFP analysis to track how the functional connectivity changes between these regions in a task dependent manner. Signal processing and causality analysis will be used to study coherence, cross frequency coupling across different areas and the direction of flow of information.