Dendritic morphology of neurons in sympathetic ganglia of the goldfish, Carassius auratus

We used intracellular dye injection to examine the dendritic morphology of postganglionic neurons in the coeliac ganglion of goldfish. About 80% of the neurons had at least one dendrite, with the mean number of dendrites per cell being 7.8 ± 5.5 (±SD, n = 37 cells). Dendrites varied in length from a few μm to more than 400 μm. Around 37% of the neurons possessed axon collaterals in addition to dendrites. These results show that postganglionic sympathetic neurons of goldfish can have a complex morphology, more like the sympathetic neurons of small mammals than those of amphibians. This raises the possibility that at least some sympathetic ganglion cells of teleost fish receive multiple convergent preganglionic inputs, suggesting a hitherto unsuspected level of complexity in these pathways.