[The role of the hypothalamus in the mechanism of positional nystagmus].
The typical positional nystagmus was induced in 30 intact rabbits with injection of 0.1-0.4 ml of 0.03-0.05% dicaine solution into the cerebral cisterna magna. The positional nystagmus resulted, supposedly, from the effect of the anesthetic upon the basal structures of the 3rd ventricle of the brain, upon the hypothalamus in particular. The trigger mechanism of the phenomenon is the displacement of the membraneous ampullae of semicircular canals at the tilting of the head. To prove this, 0.01-0.03 ml of 4% dicaine solution were injected directly into the anterior and posterior hypothalamus through a metallic cannula. When introduced into the anterior hypothalamus the dose of the anesthetic necessary for occurrence of the positional nystagmus is two or three times lesser than when it is injected into the posterior nypothalamus. In two delabyrinthed rabbits we failed to induce the nystagmus in this way.
D000818:Animals; D001931:Brain Mapping; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology; D005133:Eye Movements; D007031:Hypothalamus / Q000502:physiology*; D011187:Posture; D011817:Rabbits; D012018:Reflex; D013748:Tetracaine / Q000494:pharmacology; D014722:Vestibule, Labyrinth / Q000502:physiology*
D013748:Tetracaine
O roli gipotalamusa v mekhanizme pozitsionnogo nistagma