Pyramidal neurons

Figure 1. Dendritic morphologies of typical pyramidal neurons in different brain regions. (A) Layer 5 pyramidal neuron in the rat somatosensory cortex (courtesy of Maarten Kole). (B) Pyramidal neuron in area CA3 of the rat hippocampus (reproduced with permission from Gonzales et al. (2001).) (C) Layer 2 pyramidal neuron in the primary olfactory cortex of the mouse (unpublished work of Norimitsu Suzuki and myself). What is a pyramidal neuron? A common class of neuron found in the cerebral cortex of virtually every mammal, as well as in birds, fish and reptiles. Pyramidal neurons are also common in subcortical structures such as the hippocampus and the amygdala. They are named for their shape: typically they have a soma (cell body) that is shaped like a teardrop or rounded pyramid. They also tend to have a conical spray of longer dendrites that emerge from the pointy end of the soma (apical dendrites) and a cluster of shorter dendrites that emerge from the rounded end (basal dendrites) (Figure 1).