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Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal cells are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract .
Betz cells are not the sole source of direct connections to those neurons because most of the direct corticomotorneuronal cells are medium or small neurons. [3] While Betz cells have one apical dendrite typical of pyramidal neurons, they have more primary dendritic shafts, which can branch out at almost any point from the soma (cell body). [4]
The pyramidal tracts include both the corticobulbar tract and the corticospinal tract.These are aggregations of efferent nerve fibers from the upper motor neurons that travel from the cerebral cortex and terminate either in the brainstem (corticobulbar) or spinal cord (corticospinal) and are involved in the control of motor functions of the body.
In the hippocampus, GABAergic neurons have been found vulnerable to excitotoxic action of glutamate at the kainate receptor. [21] These receptors are most dense in sectors CA3 and CA2 of the hippocampus, where nanomolar (nM) concentrations of kainic acid have been associated with pronounced and persistent depolarization of CA3 pyramidal neurons ...
The pyramidal cells in CA3 have a unique type of dendritic spine called a thorny excrescence or thorn, only found in CA3 pyramidal cells and hilar mossy cells. The thorn has a thin single spine with a number of heads. Clusters of thorns sit on a dendrite on a broad stem.
Five cell types exist, and a majority of these cells resemble pyramidal neurons found in the cortex. [ 7 ] [ 8 ] Within the claustrum, there is no laminar organization of cell types as in the cortical layers , and the cell bodies can be a pyramidal, fusiform or circular. [ 1 ]
The pyramidal tracts (corticospinal tract and corticobulbar tracts) may directly innervate motor neurons of the spinal cord or brainstem (anterior (ventral) horn cells or certain cranial nerve nuclei), whereas the extrapyramidal system centers on the modulation and regulation (indirect control) of anterior (ventral) horn cells.
Brain cells make up the functional tissue of the brain. The rest of the brain tissue is the structural stroma that includes connective tissue such as the meninges, blood vessels, and ducts. The two main types of cells in the brain are neurons, also known as nerve cells, and glial cells, also known as neuroglia. [1]