  We suggest a modification of a comb model to describe anomalous transport in
spiny dendrites. Geometry of the comb structure consisting of a one-dimensional
backbone and lateral branches makes it possible to describe anomalous
diffusion, where dynamics inside fingers corresponds to spines, while the
backbone describes diffusion along dendrites. The presented analysis
establishes that the fractional dynamics in spiny dendrites is controlled by
fractal geometry of the comb structure and fractional kinetics inside the
spines. Our results show that the transport along spiny dendrites is
subdiffusive and depends on the density of spines in agreement with recent
experiments.
