Local Signalization in Dendrites and Mechanisms of Short-Term Memory

Abstract

Traditionally, collection of information from synaptic inputs distributed on dendrites and transmission of this information to the soma of the neuron were believed to be the only functions of these neuron compartments. In recent years, such a viewpoint was revised to a considerable extent due to novel results demonstrating that the dendrites can realize the role of structural/functional units or even complexes providing independent information processing and signaling via performing local computational operations. We propose a hypothesis that a dendrite segment, due to transient changes in the excitability of its membrane (provided by processes of postpolarizations after generation of action potentials and Hebbian-type plasticity of these processes) can play the role of a structural unit of memory. Namely, such a segment can recognize, memorize, and “forecast” sequences of input signals. A high capacity of such dendritic memory unit can be provided by the locality of electrical and corresponding biochemical processes in branches of the neuronal dendrite tree. Thus, a single dendrite segment can represent the relatively independent fundamental unit for signalization and integration in the nervous system.