Asymmetric distribution of calbindin-D28K in the ganglia habenulae of an elasmobranch fish.

Using an antibody raised against a purified chick duodenal vitamin D-dependent calcium-binding protein, the presence and distribution of calbindin has been studied immunohistochemically in the habenular ganglia of the dogfish. In the more developed left ganglion, a positive reaction was clearly observed in the neurons of the medial nucleus, whereas in the lateral nucleus, only some scarce, hardly immunostained cells appeared. In the neurons of the right habenula however, no immuno-reactivity was observed. The distribution of vitamin D-dependent calcium-binding protein in the dogfish habenulae is therefore asymmetrical. This may be due to differences in the neuronal activity between the two ganglia.