Dendritic morphology and firing patterns
In addition to ion-channel composition, dendritic morphology appears to be an important factor modulating firing pattern. In many cell types, including neocortical and hippocampal pyramidal cells, neuronal firing patterns are correlated with dendritic morphology. Results from modelling studies also suggest a direct relationship between dendritic morphology and firing pattern.
However, these studies are mainly correlative, focus on morphologically very distinct cell classes, use only the physiologically less appropriate stimulation protocol of somatic current injection, and make no distinction between the two sources of morphological variability: metrics (size of the dendritic tree, segment lengths, segment diameters) and topology (the way the segments of the dendritic tree are connected).
Consequently, the effects of dendritic size and topology on firing patterns, and the underlying mechanisms, remain poorly known.
Using computational models of pyramidal neurons, we study the effect of both dendritic size and topology on firing patterns, stimulating the cells either by current injection at the soma or by synapses distributed across the dendritic tree.
The predictions of our computational models may be tested with a recently developed technique for the targeted pruning of dendritic trees via femtosecond laser dendrotomy (Ann Go et al., 2016).