![]() ![]() Then principles will be introduced how this localization-dependence of synaptic inputs into dendrites can be compensated for. ![]() It will be discussed how the location of input synapses in a passive electrical structure affects the integration of postsynaptic potentials. This article will first summarize basic functions of passive dendritic architecture which applies for most neurons but confers variable characteristics to different types of neurons. On the other hand the question arises whether dendritic defects impact neuronal function qualitatively and to what degree of dendritic defect neuronal function can be maintained. Therefore, on the one hand it is important to determine the contribution of dendritic structure to the function of different types of healthy neurons. Although a multitude of neurodevelopmental and neurodegenerative disorders coincides with dendritic defects, it often remains unclear whether these structural defects are the cause or a consequence of the dysfunction. Dendritic structure analysis is further bedeviled by dendrites exhibiting voltage-gated ion channels which themselves vastly modify function and computing power. In most cases, however, the specific function of dendritic architecture remains largely elusive. Accordingly, in different types of neurons with different functions dendritic gestalt differs significantly, and dendritic architecture often serves to classify neuron types. Second dendritic structure impacts the temporal and spatial integration of postsynaptic potentials. Thus, dendritic structure influences the number of synapses as well as the wiring logic within neuronal networks. First dendrites expand the receptive surface of neurons, and their shape dictates how many and which presynaptic neurons can contact a postsynaptic dendritic arbor. Therefore, dendritic architecture has two fundamental functions in the nervous system. Despite a number of exceptions, for most neurons this rule prevails to the present. Cajal established the foundation for the neuron doctrine by suggesting dendrites to be the synaptic input regions of neurons, and that information processing travels from dendritic regions towards axon terminals and output synapses (“the theory of dynamic polarization”, Shepherd, 1991). Already around 1900 the Spanish neuroanatomist Ramón y Cajal proposed that neurons possess two discrete functional domains, the axonal and the somatodendritic compartment. Neurons represent the cellular substrate for information processing in the nervous system. ![]()
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