65Zn uptake in the rat cerebellum and brainstem.

We have studied the autoradiographic uptake of 65Zn in the cerebellum and brainstem of the rat, contrasting these results with Timm's positivity in these structures. Both, autoradiographic uptake and histochemical positivity, have demonstrated Zinc in a location that could be accepted as in climbing fibres and glomeruli of the cerebellum cortex, and also in brainstem neurons that project their axons to the cerebellum cortex, suggesting a circuit where zinc may act as a neuromodulator.