Pyramidal cells, also known as pyramidal neurons, are the predominant excitatory neurons in the mammalian cerebral cortex and hippocampus, distinguished by their characteristic pyramid-shaped soma, extensive basal dendrites emanating from the base, and a single prominent apical dendrite that ascends toward the pial surface, often branching into a tufted arbor in layer 1.[1][2] These neurons utilize glutamate as their primary neurotransmitter to transmit excitatory signals and form the majority of cortical neurons, accounting for 70–85% of the total population in the neocortex.[2] Their dendritic trees, covered in spines that host most excitatory synapses, enable compartmentalized processing of inputs, making them central to neural computation and information flow in the brain.[1]Structurally, pyramidal cells exhibit a conserved core morphology across species and brain regions, with variations that reflect functional specialization.[1] The soma is typically triangular, giving rise to multiple basal dendrites that fan out locally and the apical dendrite that integrates inputs from distant layers, such as those from layer 1.[1][3] In the neocortex, they are distributed across layers II through VI, with somata primarily in layers II–III, V, and VI, while in the hippocampus, they populate regions like CA1 and CA3.[1][2] Subtypes are classified based on laminar position, dendritic morphology, and projection targets; for instance, thick-tufted layer 5 pyramidal neurons feature wide apical tufts and robust axonal arbors that ramify locally and extend to subcortical structures like the thalamus, striatum, and brainstem.