The classification of medial septum-diagonal band cells as theta-on or theta-off in relation to hippocampal EEG states.
The discharge patterns of cells located in the medial septum (MS)/vertical limb of the Diagonal Band of Broca (vDBB) were recorded simultaneously with hippocampal formation large amplitude irregular activity (LIA), or theta, in urethane-anesthetized rats. The main conclusion was that the majority of cells in the MS/vDBB were theta-related and could be classified according to the same scheme developed for theta-related cells in the hippocampal formation. That is, cells were classified as theta-on or theta-off, with subtypes defined as tonic or phasic, linear or non-linear. The discharge properties of hippocampal and MS/vDBB cell populations were compared. It was argued that this classification scheme encompassed all the crucial properties of theta-related cells in the hippocampal formation and the MS/vDBB. An alternative model to the septal pacemaker hypothesis, concerning the role of the medial septum in the generation of hippocampal formation theta activity, was presented and discussed.
Ford
R D
RD
Department of Psychology, University of Calgary, Alta., Canada.
Colom
L V
LV
Bland
B H
BH
D000818:Animals; D004569:Electroencephalography; D005625:Frontal Lobe / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D051381:Rats; D012686:Septal Nuclei / Q000502:physiology*; D013826:Theta Rhythm