Supersensitivity after intraventricular 6-hydroxydopamine: relation to dopamine depletion

6-Hydroxydopamine increased behavioral response to L-DOPA in proportion to the decrease of dopamine (DA) and DA utake in rat striatum. The increase response to apomorphine, however, only occurred after greater than 80% DA loss. Thus, 6-hydroxydopamine may induce postsynaptic changes only following large lesions.