BRAIN STEM SYSTEMS AND BEHAVIOR.
Final scientific rept. 1 Jun 66-31 May 67,
MILAN UNIV (ITALY) ISTITUTO DI PATOLOGIA MEDICA
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Experiments were devised with the aim of further clarifying the hemodynamics of deep desynchronized sleep. Information was sought along two different approaches. 1 Comparison of arterial pressure changes in desynchronized sleep before and after various kinds of heart denervation showed that the neural control of the heart is not basically involved in the blood pressure fall occurring in sleep. 2 Experiments in which, besides arterial pressure, cardiac output was continuously measured by means of electromagnetic flowmeters, showed that hypotension during desynchronized sleep usually results from a decreased peripheral resistance with only a slight decrease in cardiac output. This suggests vasodilatation brought about by decreased sympathetic activity. A different hemodynamic pattern cardiac output dramatically decreased, proportionally more than arterial pressure was observed only in a few episodes of desynchronized sleep in sino-aortic deafferented cats, whenever signs of cerebral ischemia occur. An experimental program was started to study the influence of inhibitory and excitatory visceral afferents from the vagi andor aortic nerves upon hippocampal pyramidal neurons, recorded intracellularly. Author
- Anatomy and Physiology