[The destruction of perikaryas of the mesencephalic reticular formation and the posterior hypothalamus does not cause major disorders of awakening in the cat].

Ibotenic acid microinjections have been realized at the level of the mesencephalic reticular formation and the posterior hypothalamus in 7 cats. This technique has led to a quasi-total destruction of cell bodies in the two areas (including the histaminergic neurons). 2 to 3 days after such lesions, there were no major effects on behavioral waking. These results do not favor the hypothesis of the existence of a waking system at the level of the mesencephalic reticular formation and/or posterior hypothalamus.