1School of Mathematical Sciences, University of Nottingham, Nottingham, UK
Dendrites are the main site for synaptic input to neurons. They are usually considered as pure post-synaptic elements that serve as a spatio-temporal filter for the synaptic input to the soma. This is not the whole story however, as dendrodendritic junctions have been shown to be prominent in some brain areas, for example the olivocerebellar system [Zeeuw et al., 1997] and the olfactory bulb [Christie and Westbrook, 2006]. These junctions mean that the dendrites of cells function as both post and pre-synaptic elements simultaneously. Here we consider a network of gap-junction coupled passive dendrites, each possessing an active spiking soma. Specifically we model a dendrite with the cable equation and a soma with the piece-wise linear models, so that the network model is analytically tractable. These piece-wise linear models are capable of capturing both Type I and Type II behaviour. The dendrites are modelled as a chain of passive compartments on which a gap-juction is placed.
Earlier work by Nadim and Golowasch has already uncovered the effect of changing cable diameter on signal transmission between dendrites with gap-junctions [Nadim and Golowasch, 2006]. Here we focus on the emergent network rhythms resulting from information flow both to and from an active soma in a network with gap junctions between dendrites.
[Christie and Westbrook, 2006] Christie, J. and Westbrook, G. (2006). Lateral excitation within the olfactory bulb. J. Neurosci, 26(8):2269-2277
[Nadim and Golowasch, 2006] Nadim, F. and Golowasch, J. (2006). Signal transmission between gap-junctionally coupled passive cables is most effective at an optimal diameter. J. Neurophysiol., 95(6):3831-3843
[Zeeuw et al., 1997] Zeeuw, C.D., Koekkoek, s., Wylie, D. and Simpson J. (1997). Association between dendritic lamellar bodies and complex spike synchrony in the olivocerebellar system. J. Neurophysiol., 77:1747-1758