The neurological basis of striatally induced head-turning in the rat: The effects of lesions in putative output pathways

Turning of the head towards the contralateral side was induced in the conscious unrestrained rat by electrical stimulation of the neostriatum through permanent indwelling electrodes. The possible output pathways by which this response was mediated were examined using ablative and neurotoxin lesions. Contralateral head-turning was abolished or greatly attenuated by electrolytic lesions of the globus pallidus or substantia nigra on the stimulated side. Lesions of the sensory cortex, superior colliculi, ventromedial thalamic nucleus or dopaminergic nigrostriatal pathway were ineffective.It is concluded that descending projections from the pallidum and/or substantia nigra to the brain stem may be important for the mediation of head-turning induced by striatal stimulation.