Septal nuclei

Septal area
Lateral and medial septal nuclei of the mouse brain
Details
Identifiers
Latin	nuclei septales
NeuroNames	hier-241
Dorlands /Elsevier	n_11/12583395
BAMS	SEPTAL-NUCLEI
TA	A14.1.09.266
FMA	61845
Anatomical terms of neuroanatomy []

The septal nuclei (medial olfactory area) are a set of structures that lie below the rostrum of the corpus callosum, anterior to the lamina terminalis (the layer of gray matter in the brain connecting the optic chiasma and the anterior commissure where the latter becomes continuous with the rostral lamina). The septal nuclei are composed of medium-size neurons which are classified into medial, lateral, and posterior groups. The septal nuclei receive reciprocal connections from the olfactory bulb, hippocampus, amygdala, hypothalamus, midbrain, habenula, cingulate gyrus, and thalamus. The septal area (medial olfactory area) has no relation to the sense of smell, but it is considered a pleasure zone in animals. The septal nuclei play a role in reward and reinforcement along with the nucleus accumbens. In the 1950s, Olds & Milner showed that rats with electrodes implanted in this area will self-stimulate repeatedly (i.e. press a bar to receive electrical current that will stimulate the neurons). Experiments on the septal area of man have taken place since the 1960s.

The dorsal septum projects to the lateral preoptic area, lateral hypothalamus, periventricular hypothalamus and midline thalamus.

Fibers from the ventral half of the septum project topographically to the hippocampal formation, thalamus, hypothalamus and midbrain. Specifically, neurons located along the midline in the vertical limb of the diagonal band of Broca project through the dorsal fornix to all CA fields of the dorsal hippocampus and adjacent subicular cortex. Other fibers from this region project through the stria medullaris to the medial and lateral habenular nuclei, the paratenial and anteromedial nucleus of the thalamus, and through the medial forebrain bundle to the pars posterior of the medial mammillary nucleus.