Dendrite

A dendrite is a tree-like extension of a neuron that receives most of the synaptic inputs from other neurons. Dendrites vary in size and shape, forming a dendritic arbor that extends from the cell body and often includes basal and apical branches. On many dendrites, small protrusions called dendritic spines host the majority of excitatory synapses, providing individual sites for synaptic signaling.

Functionally, dendrites collect and integrate synaptic signals. Inputs produce postsynaptic potentials that travel along the dendritic shaft toward the soma, where they influence whether the neuron fires. Dendrites exhibit both passive electrical properties and active conductances mediated by voltage-gated ion channels and receptor currents, enabling local processing and nonlinear events such as dendritic spikes and NMDA receptor–dependent plateau potentials.

Backpropagating action potentials from the soma can invade dendrites, interacting with synaptic inputs and contributing to synaptic plasticity. Calcium signaling and other intracellular pathways link dendritic activity to changes in synaptic strength and structure, supporting learning and memory. Through these plastic changes, the properties of dendrites are continually refined during development and experience.

Dendrite morphology and spine density vary across neuron types and developmental stages. Pyramidal neurons typically have extensive apical and basal dendrites, while some interneurons possess shorter, simpler trees. Dendritogenesis, branching patterns, and spine remodeling shape mature neural circuits and affect information processing.

Research on dendrites employs histological staining and imaging techniques such as Golgi staining and two-photon microscopy. Abnormal dendritic development or spine remodeling is associated with several neurological and psychiatric conditions, highlighting the role of dendrites in neural computation.