Parkinson's syndrome induced in cats by the use of 6-hydroxydopamine. Observations of behavior and motor disorders.

The possibility of inducing Parkinson's syndrome in cats was investigated in three kinds of lesions: by microinjection of 6-hydroxy dopamine (6-OHDA) into the pars compacta of substantia nigra (SNC), bilateral injection into the SNC and globus pallidus (GP) and into the SNC and caput nuclei caudati (NC). In all three kinds of lesions of the dopaminergic system disturbances of behavior involving specially the motor system were obtained, corresponding to the parkinsonism syndrome--in the form of bradykinesia-akinesia, increased muscle tonus of plastic type, vegetative disorders (sialorrhea, pupils) and psychic disorders such as lack of interest in the surroundings and food. The character of the enhanced muscle tonus typical for extrapyramidal disturbances was confirmed by EMG examination. The parkinsonism-like syndrome induced in the cats was transient and receded after several weeks.