The medial septal nucleus (MS) is one of the
septal nuclei. Neurons in this nucleus give rise to the bulk of efferents from the septal nuclei. A major projection from the medial septal nucleus terminates in the
hippocampal formation
The hippocampal formation is a compound structure in the medial temporal lobe of the brain. It forms a c-shaped bulge on the floor of the inferior horn of the lateral ventricle. Typically, the hippocampal formation is said to included the dent ...
.
It plays a role in the generation of
theta waves in the hippocampus.
Specifically, the
GABAergic
In molecular biology and physiology, something is GABAergic or GABAnergic if it pertains to or affects the neurotransmitter gamma-aminobutyric acid (GABA). For example, a synapse is GABAergic if it uses GABA as its neurotransmitter, and a GABAergic ...
cells of the medial septum that act as theta pacemakers target
dentate gyrus
The dentate gyrus (DG) is one of the subfields of the hippocampus, in the hippocampal formation. The hippocampal formation is located in the temporal lobe of the brain, and includes the hippocampus (including CA1 to CA4) subfields, and other su ...
, CA3, and CA1 interneurons. Pacemaking MS interneurons express
hyperpolarization-activated cyclic nucleotide-gated (HCN) channels which likely, at least partially, mediate their pacemaker properties.
It is composed of GABAergic cells, glutamatergic cells, and cholinergic cells. Each cell-type carries out different functions. In addition to the theta wave generation, it has recently been discovered that medial septum also serves as an important node for sensory valence processing. For example, Vglut2 neurons in medial septum respond strongly to noxious sensory stimulation.
References
Cerebrum
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