![]() ![]() Previous work by the same group had shown that in up to 50% of mouse hippocampal pyramidal cells, the axon emanates from a basal dendrite, rather than from the soma. Hodapp and coworkers 4 have now reported a new computational mechanism in cortical networks which is based on the location of the axon. While most studies of neuronal signal integration focus on dendrites, more recent work points towards the importance of the axon’s location and properties. Thus, dendritic structure and function allow for complex computations at the single-neuron level. The interplay between distal and proximal dendritic segments has been suggested to underlie directed attention or even consciousness. The resulting depolarization amplifies more proximally inserting ‘specific’ inputs, e.g. A prominent recent hypothesis claims that activation of specific cortical networks goes along with a depolarization of the most distal dendrites by ‘unspecific’ excitatory synapses. Secondly, pyramidal neurons within cortical networks typically have a layered structure with distinct inputs arriving at different dendritic domains. Accordingly, high-resolution measurements have revealed several signal amplification mechanisms along dendrites, which may even give rise to dendritic spikes resembling action potentials. We highlight two prominent examples: First, the complex form of neuronal dendrites can lead to strong attenuations of signals if they are generated at remote locations or small-diameter dendritic branches. However, it has experienced important extensions over the years. The reductionist integrate-and-fire model of neurons has been quite useful to explain dynamic processes in networks. ![]()
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