Abstract
Vinblastine injected into the eyes of pigeons had a detrimental effect on the amplitude of the postsynaptic evoked potential in the optic tectum; impulse conduction of the optic nerve was not influenced. The depression of the postsynaptic evoked potential was dependent on the dosage. Only 20 and 100 μg vinblastine had an influence; no influence was observed with 10 μg vinblastine. The reversible depression was seen from the third day after injection to between the 21st and the 28th day after injection, and in that period it remained constant. The latency of the response was not influenced by vinblastine.