Septal region

Regio septalis

Septum, Nucleus septalis lateralis, Nucleus septalis medialis, Cell group Ch1 , Ch1 , Brain reward system, Drug addiction

The area is located rostral at the base of the septum pellucidum, slightly above Meynert's basal nucleus, and contains some small accumulations of grey matter: the so-called septal nuclei (nucleus septalis lateralis and nucleus septalis medialis).

The septal region is included in the basal forebrain. The region is connected to the amygdala via Broca's diagonal band, to the bulbus olfactorius via the inner olfactory streak, and to the hippocampal complex via fornix and striae longitudinales. The nucleus septalis medialis contains cell group Ch1 that produces acetylcholine and will thus "irrigate" the hippocampus with acetylcholine.

Septal neurons are thought to be responsible for the theta wave activity that the hippocampus exhibits when moving around in its environment.

Septum, in turn, is under the influence of a theta wave activity that emanates from nuclei in the wart body and has to do with the regulation of the individual's alertness, including the nucleus tuberomamillaris (histamine nucleus).

The septal region is considered one, perhaps the most important, of the "pleasure centers" of the brain. Electrical stimulation of the septum in humans gives rise to an extraordinarily strong feeling of well-being. Laboratory animals with an implanted ability to "self-stimulate" (pedal-linked excitation electrode) their septal region are in some cases so completely preoccupied with stimulating themselves that they stop eating and drinking (Olds J, Milner P (1954). "Positive reinforcement produced by electrical stimulation of septal area and other regions of rat brain". J Comp Physiol Psychol 47 (6): 419–27.). The septal region, together with primarily the nucleus accumbens and area tegmentalis ventralis, is considered to be part of the brain's so-called reward system, which is of the greatest importance in connection with the development of a drug addiction (see also Calleja's islands).

If the septum is removed/destroyed on both sides, an extremely irritable condition arises, so-called septal rage.