For example, it allows a neuron to use Hebbian synaptic mechanisms to store information. The location independence of integration has several functional benefits. The precise nature of the synaptic change is unknown but it is likely to involve an increase in the number of release sites per terminal and increases in the number of synaptic receptors. However, their exact effect will depend on the specific spatio-temporal characteristics of the input.Ĭhanges in synaptic conductance are the primary mechanism for reducing location dependence of integration in CA1 neurons. Active dendritic conductances endow neurons with the ability to produce both linear and nonlinear interactions between synaptic inputs. The active properties of the dendritic membrane are more effective than neuron morphology in reducing the location dependence of integration. Neuron morphology can reduce the location dependence of synaptic integration but its effect cannot completely counteract the filtering effects of dendrites, indicating that the contribution of other cellular properties to linearization is more important. Three broad categories of cellular properties are involved in the normalization of synaptic integration - neuron morphology, active properties of the membrane and synaptic mechanisms. This spatial distribution, together with the cable properties of dendrites could cause a pronounced location-dependent variability in the integration properties of synaptic inputs, unless the filtering properties of dendrites are countered.Īlthough theoretical analyses predict a marked location dependence for the integration of spatially segregated synaptic input, evidence indicates that the dendrites of some cell types can counteract the influence of filtering on the three main elements of synaptic integration - unitary EPSP amplitude, and temporal and spatial summation.Īs a result of countering the filtering properties of dendrites, synaptic integration is essentially independent of input location. Neurons receive a plethora of synaptic inputs that are widely spread across their dendritic arbours.

Mechanisms dendrite axon patterning