Somato-dendritic processing of postsynaptic potentials I: Passive properties of dendrites

Neurons of the mammalian central nervous system receive many afferents which contact different parts of their somato-dendritic arborization. When these afferents are activated, if their combined effect is depolarizing enough, they trigger the firing of sodium action potentials in the postsynaptic neuron. Classically, it is accepted that these action potentials are generated at a central point in the neuron, at the level of the initial segment of the axon (action potential generating zone). The action potential propagates back to the soma and forward to the axon and axon terminals. Action potentials are the response of the postsynaptic neuron. The events that lead to a postsynaptic response can be separated into several stages. This chapter looks at the conduction and the summation of synaptic currents (first type of currents) over the dendritic tree.