dendritos

Dendritos, also known as dendrites, are the branched extensions of neurons that receive inputs from other nerve cells. Extending from the cell body, dendrites form an arbor that increases the surface area available for synapses and enables the neuron to integrate a wide range of signals.

Most excitatory synapses form on dendritic spines, tiny protrusions along the dendritic branches. Dendrites contain cytoskeletal elements such as microtubules, neurofilaments, and actin, which support their shape and enable transport of proteins and organelles.

The electrical properties of dendrites are complex. Neurotransmitter binding on receptors (for example AMPA and NMDA receptors for glutamate, GABA receptors for inhibitory inputs) generates postsynaptic potentials that spread toward the soma. Dendrites can also host local regenerative events, called dendritic spikes, produced by voltage-gated ion channels and NMDA receptor activity. In many neurons, action potentials propagate back into the dendritic tree (back-propagating action potentials), influencing synaptic strength.

Dendrites participate in nonlinear and spatially distributed integration of inputs, allowing the neuron to perform computations before signals reach the axon hillock. They exhibit plasticity: synaptic strength can be increased or decreased (LTP/LTD), and the structure of dendritic spines can grow, shrink, or appear during learning and development.

Arbor complexity and branching patterns vary among neuron types (for example, pyramidal neurons with apical and basal dendrites versus Purkinje cells with dense dendritic trees). Dendritic development and pruning shape mature neural circuits, and abnormalities in dendritic structure are linked to neurodevelopmental and neurodegenerative disorders.