Dendrite

What is a Dendrite?

A dendrite is a branched, tree-like extension of a neuron that receives and integrates incoming signals from other neurons or sensory cells. Dendrites process these inputs through both passive and active electrical properties. In many neurons, the output action potential begins in the axon initial segment rather than the cell body.

Key Features of Dendrites

• Structure

  Many dendrites form a branching tree that provides surface area for incoming connections. The arrangement of those branches affects how inputs combine. The morphology of dendrites varies between different types of neurons and can be influenced by factors such as age, experience, and neural activity.

• Synaptic Connections

  A neuron's dendritic tree can receive many synaptic connections, with numbers varying widely across neuron types and branches. These connections, known as synapses, are the sites where incoming signals are received and transmitted to the neuron. The strength and efficacy of these synapses can change over time, a process known as synaptic plasticity, which is thought to underlie learning and memory.

• Signal Integration

  Dendrites receive and integrate incoming signals in the form of neurotransmitters, which bind to specialized receptors on the dendritic membrane. The binding of neurotransmitters to these receptors can generate electrical signals, known as postsynaptic potentials, which can either be excitatory or inhibitory. The integration of these signals determines whether the neuron will generate an output signal in the form of an action potential.

Dendrite Functions in Neural Communication and Learning

• Neural Communication

  A dendrite does more than pass a message along. Where an input arrives and how it combines with other inputs can change the neuron’s response.

• Learning and Memory

  The morphology and connectivity of dendrites are thought to be involved in learning and memory processes, as changes in synaptic strength and dendritic structure can alter the flow of information within neural circuits. These changes, known as synaptic and structural plasticity, have been linked to the formation and consolidation of new memories, as well as the refinement of neural circuits during development.

• Neurological Disorders

  Abnormalities in dendritic structure or function have been implicated in various neurological disorders, such as Alzheimer's disease, autism, and schizophrenia. These links do not mean that a single dendritic abnormality explains a disorder or identifies a treatment.

Sources and evidence

• Greg J. Stuart and Nelson Spruston: Dendritic integration: 60 years of progress.