Basalidendriittien

Basalidendriittien, or basal dendrites, are the dendritic processes that emanate from the base of a neuron’s soma. They form an essential part of the neuron's local circuitry by receiving and integrating a substantial portion of synaptic input, thereby helping to determine the cell’s output. Basal dendrites are most prominently found on cortical pyramidal neurons and in certain hippocampal cells, where they contribute to the proximal portion of the dendritic tree in close proximity to the soma. This positioning contrasts with apical dendrites, which extend toward more distant cortical layers.

Morphology and distribution vary by neuron type. Basal dendrites are often shorter and highly branched compared to distal or apical dendrites, and they carry a dense array of dendritic spines that host excitatory synapses. Their arrangement supports the integration of local and nearby network activity, enabling rapid processing of incoming signals within cortical and hippocampal microcircuits.

Inputs and function. Basal dendrites receive a mix of excitatory inputs from neighboring cortical and subcortical regions, as well as inhibitory inputs from local interneurons. Through spatial and temporal summation of these inputs, basal dendrites contribute to the generation of action potentials and influence the timing and pattern of neuronal firing, thereby shaping information processing and network dynamics.

Plasticity and development. The synapses on basal dendrites exhibit activity-dependent plasticity, including long-term potentiation and depression, which underlies learning and memory processes. Basal dendrites develop and mature during postnatal life, with their structure and synaptic connectivity modifiable by experience.

Clinical relevance. Alterations in basal dendritic structure and spine density have been reported in various neurological and psychiatric conditions, reflecting changes in local circuitry and cortical processing. Basal dendrites thus play a key role in normal brain function and its disruption in disease.