Distribution of neuroepithelial cells and neurons in the trout gill filament: comparison in spring and winter

Study of the distribution of neuroepithelial cells and neurons along the gill filament of rainbow trout (Oncorhynchus mykiss) showed that the density of neuroepithelial cells is maximal near the extremity of the filament, whereas the density of neurons is maximal at the base of the filament. Comparison of densities in spring and winter shows that in winter, neuroepithelial cell density diminishes whereas neuron density increases; in spring, these relationships are inverted: neuroepithelial cell density increases whereas neuron density decreases.