Tuesday, January 17, 2012
The septal area, or septal nuclei, are structures in the brain hemispheres in the form of thin sheets of brain tissue. They form the medial wall of the lateral ventricle frontal horn. From the septal area, there are strong connections to the hippocampus, the central structure of the limbic system. Cholinergic and GABAergic neurons of the medial septal nucleus project to the hippocampus and the dentate gyrus; collaterals of the pyramidal cells project back to the lateral septal nucleus. As with stimulation of the amygdaloid body, electrical stimulation of the septal area triggers oral reactions (licking, chewing, retching), excretory reactions (defecation, urination), and sexual reactions (erection). The septal area, especially the diagonal band of Broca, is also the preferred localization for self-stimulation experiments in the rat.