On the inferior olive of the albino rat

The average of neuron counts made in five rat inferior olives was 24,400 neurons per olive, i.e., 48,800 per rat, — 6.8 times fewer than the number of rat cerebellar Purkinje cells. The medial accessory olive was larger, both in terms of volume and cell numbers, than either the dorsal accessory or principal olives. The overall packing density, determined in one olive, was 43,900 neurons/mm 3 , but there were local fluctuations within the olive. In particular, packing density was somewhat higher at the rostral end of the medial accessory olive.