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.
Department of Psychology, University of Calgary, Alta., Canada.
R D
RD
Ford
L V
LV
Colom
B H
BH
Bland
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