Date of Completion

Spring 5-1-2015

Thesis Advisor(s)

Ian Stevenson

Honors Major

Physiology and Neurobiology

Disciplines

Behavioral Neurobiology | Cognitive Neuroscience | Cognitive Psychology | Computational Neuroscience | Experimental Analysis of Behavior

Abstract

The aim of this project was to determine coherence between two types of neural recordings which can be obtained from the rat hippocampus: spikes and local field potentials. Extracellular recording makes it possible to determine spiking activity from individual neurons in the vicinity of the recording electrode. Local field potential recording gives a combined activity of many neurons (thousands) at once to determine an overall picture of the coordination of the cells in real time. Here we examine the relationship between these two signals, focusing on place cells which spike at their maximal rate only at certain positions in physical space. Examining these cells using spike-field coherence techniques we determined that during running and rest behaviors, the place cells have different patterns of firing. During run sessions on a linear track, they would fire maximally at their preferred position on the track and showed high spike-field coherence with the theta band (4 Hz – 10 Hz) of the LFP. During rest sessions on the same track, when ripples occur, the place cells would fire sequentially, essentially replaying back the run session firing at a much faster timescale and with high spike-field coherence in the gamma band (100 Hz – 250 Hz) of the LFP.