Prolonged Stimulation of the Head of the Caudate Nucleus

While the motor and postural effects of electric stimulation of the striatum have been repeatedly examined in acute experiments (Ferrier,^11,12 1873, Danilewski,⁷ 1875; Tower,⁴⁰ 1936; Mettler et al.,³³ 1939; Freeman and Krasno,¹⁴ 1940; Gerebetzoff,¹⁶ 1941; Akert and Andersson,³ 1951; Kaada,²⁶ 1951; Heath and Hodes,²¹ 1952; White and Himwich,⁴³ 1957; Umbach,⁴¹ 1959), there are no reports on prolonged striatal stimulation as far as we could ascertain. Forman and Ward's¹³ "chronic experiments" deal with stimulation of a few seconds' duration applied through chronically implanted electrodes. It has been pointed out that uninterrupted, continuous electrical striatal stimulation is ineffectual (Mettler³¹). We have therefore tried to produce prolonged stimulation of this ganglion by injection of alumina cream and to analyze its rather obscure influence upon various parts of the brain by a combination of such stimulation with electrographic studies and extirpation