King, Charles; (1997) Rhythmic activity in cells of the medial septum and diagonal band of Broca in freely moving rats. Doctoral thesis (Ph.D), UCL (University College London).

Text Rhythmic_activity_in_cells_of_.pdf Download (19MB)

Abstract

This thesis presents results from simultaneous, chronic recordings from the septum/diagonal band of Broca cells in freely moving rats. The rats were trained to run for a food reward in a feature-rich environment from end to end of a linear track, which was oriented in one of eight directions. The cells displayed similar activity profiles as those seen in anaesthetised rats, including: highly rhythmic bursting cells; cells with variable rhythmicity; and cells that displayed no rhythmicity. All rhythmic cells fired in phase with hippocampal theta rhythm. The preferential phases of the cells varied widely, but tended to correspond to two poles at the positive and negative peaks of the theta rhythm and were maintained over time. The highly-rhythmic cells were strongly phase-locked to hippocampal theta rhythm, but often displayed rhythmic activity in the absence of theta, particularly before the start and after the end of a burst of theta in the hippocampus. These cells also varied in terms of burst reliability, with some cells demonstrating a significant number of burst failures during theta rhythm. Those cells that were most clearly phase-locked with the theta rhythm also showed an increase in frequency of burst firing corresponding to an increase in the rat's running speed. Cells were also found whose rhythmicity showed significant variation depending on the spatial orientation of the linear track and the direction of motion of the rat. The findings are discussed with reference to the mechanisms of theta rhythm generation and current work concerning temporal coding in the nervous system, as opposed to coding by rate modulation.

Download activity - last month

Export as XMLCSVJSON

Download activity - last 12 months

Export as CSVXMLJSON

Downloads by country - last 12 months

Export as CSVXMLJSON

Archive Staff Only

View Item