In the previous chapter, we used a single compartment model to study the mechanisms for the activation of voltage-activated channels, which produce neuron firing. Next, we need to understand how inputs to the neuron affect the potential in the soma and other regions that contain these channels. The following chapter deals with the response of the neuron to synaptic inputs to produce postsynaptic potentials (PSPs). In this chapter, we concentrate on modeling the spread of the PSP through the

more »

... ritic tree. Dendrites are strikingly exquisite and unique structures. They are the largest component in both surface area and volume of the brain and their specific morphology is used to classify neurons into classes: pyramidal, Purkinje, amacrine, stellate, etc. (Fig. 5.1) . But most meaningful is that the majority of the synaptic information is conveyed onto the dendritic tree and it is there where this information is processed. Indeed, dendrites are the elementary computing device of the brain. A typical dendritic tree receives approximately ten thousand synaptic inputs distributed over the dendritic surface. When activated, each of these inputs produces a local conductance change for specific ions at the postsynaptic membrane, followed by a flow of the corresponding ion current between the two sides of the postsynaptic membrane. As a result, a local change in membrane potential is generated and then spreads along the dendritic branches. How does this spread depend on the morphology (the branching pattern) of the 51