title: Variations of histamine concentration in sleep and arousal hemodialysates (seasonal, thalamic and reticular influences).
abstract: In hemodialysates of cerebral venous blood from rabbits kept asleep by electrical stimulation of the somnogenic intralaminar thalamus, a seasonal correlation was found between the histamine (H) concentration and the external daily temperature, with a minimum in winter and a maximum in summer. By contrast, in dialysates of rabbits aroused by electrical stimulation of the midtrain reticular formation, the H concentration reached in winter the same high level as in summer. During the winter, stimulation of the waking midbrain reticular system increased the H-level of the cerebral blood dialysate, whereas that of the somnogenic intralaminar thalamus did not enhance, sometimes even lowered, the H-concentration. This suggests that the mechanism of H release in blood might be associated with the midbrain activating reticular system and moderated by the intralaminar thalamus.
mesh_terms: D000818:Animals; D001143:Arousal / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography; D006632:Histamine / Q000097:blood*; D007082:Ileum / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D011817:Rabbits; D006435:Renal Dialysis; D012154:Reticular Formation / Q000502:physiology*; D012621:Seasons; D012890:Sleep / Q000502:physiology*; D013788:Thalamus / Q000502:physiology*
chemical_list: D006632:Histamine