Contrasting properties of medial septal neurons projecting to hippocampus or interpeduncular nucleus in the rat.
The properties of neurons of the medial septal nucleus and of the nucleus of the diagonal band of Broca which project to hippocampus or to interpeduncular nucleus were compared in rats anesthetized with urethane. Neurons projecting to the interpeduncular nucleus had a slower conduction velocity and a lower spontaneous discharge rate. In contrast, their responses to various putative neurotransmitters (glutamate, GABA, acetylcholine) were similar. In a few cases, neurons projecting to both structures (i.e., with branched axons) were observed. Both septohippocampal and septointerpeduncular pathways are known to be partly cholinergic. Our results show that they originate from two independent populations of medial septal-nucleus of the diagonal band of Broca neurons with different physiologic properties.
Bassant
M H
MH
Unité de Recherches de Neurophysiologie Pharmacologique, INSERM U. 161, Paris, France.
Joly
M
M
Jobert
A
A
Lamour
Y
Y
D000818:Animals; D005625:Frontal Lobe / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D008636:Mesencephalon / Q000502:physiology*; D009431:Neural Conduction; D009434:Neural Pathways / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D012686:Septal Nuclei / Q000502:physiology*