Baroreceptor activity potentially facilitates cortical inhibition in zero gravity

Baroreceptor stimulation induces cortical inhibition. With blood not drawn by gravity from the upper to lower body, adopting a less upright posture leads to increases in thoracic blood volume and baroreceptor stimulation. Consistent with these effects are observations of cortical activity being inhibited when reclining or tilted head-down. As with less upright postures, in zero gravity there is a redistribution of blood towards the upper body that stimulates baroreceptors. Effects associated with this stimulation could be expected to facilitate an inhibition of cortical activity during zero gravity, as recently reported to occur during parabolic flight (Schneider et al., 2008. What happens to the brain in weightlessness? A first approach by EEG tomography. NeuroImage 42, 1316-1323).

[1]  C. Berridge,et al.  The locus coeruleus–noradrenergic system: modulation of behavioral state and state-dependent cognitive processes , 2003, Brain Research Reviews.

[2]  A. Gabrielsen,et al.  Arterial pressure in humans during weightlessness induced by parabolic flights. , 1999, Journal of applied physiology.

[3]  R. Cole,et al.  Postural baroreflex stimuli may affect EEG arousal and sleep in humans. , 1989, Journal of applied physiology.

[4]  D. Lipnicki.  Higher sensitivity to perithreshold odors when sitting than when supine may be correlated with postural differences in locus coeruleus activity. , 2007, Chemical senses.

[5]  M. Elam,et al.  Regulation of locus coeruleus neurons and splanchnic, sympathetic nerves by cardiovascular afferents , 1984, Brain Research.

[6]  K. Inui,et al.  Baroreceptor inhibition of the locus coeruleus noradrenergic neurons , 1994, Neuroscience.

[7]  J. Lacey.  Somatic response patterning and stress : some revisions of activation theory , 1967 .

[8]  L. A. Ivanova.  Orthostatic changes in the EEG power spectra of normal subjects: effect of aging. , 1988, Electroencephalography and clinical neurophysiology.

[9]  J. Cui,et al.  Sympathetic outflow to muscle in humans during short periods of microgravity produced by parabolic flight. , 1999, American journal of physiology. Regulatory, integrative and comparative physiology.

[10]  D. Lipnicki,et al.  Thinking on your back: solving anagrams faster when supine than when standing. , 2005, Brain research. Cognitive brain research.

[11]  T. Svensson,et al.  Control of behaviour and brain noradrenaline neurons by peripheral blood volume receptors , 2005, Journal of Neural Transmission.

[12]  D. Vaitl,et al.  Baroreceptor Stimulation and Changes in EEG and Vigilance , 1991 .

[13]  D. Lipnicki,et al.  AN EFFECT OF POSTURE ON ANTICIPATORY ANXIETY , 2008, The International journal of neuroscience.

[14]  T. Svensson,et al.  Brain noradrenergic neurons in the locus coeruleus: inhibition by blood volume load through vagal afferents , 1979, Brain Research.

[15]  E. Lindholm,et al.  Cardiac-related cortical inhibition during a fixed foreperiod reaction time task. , 1986, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[16]  T. Elbert,et al.  Psychophysiology of arterial baroreceptors and the etiology of hypertension , 2001, Biological Psychology.

[17]  T Kamo,et al.  Central volume expansion is pivotal for sustained decrease in heart rate during seated to supine posture change. , 2001, American journal of physiology. Heart and circulatory physiology.

[18]  Heather Carnahan,et al.  What happens to the brain in weightlessness? A first approach by EEG tomography , 2008, NeuroImage.