Hyponatremia is among the most comon conditions found in clinical medicine. The main goal of this project is to study the effect on the brain of the adaptation to acute and chronic hyponatremia, and the brain's response to correction of hyponatremia. We have shown in a rat model that rapid increases in plasma sodium concentration or plasma osmolality can disrupt the blood brain barrier (BBB); that this disruption occurs at a lower plasma osmolality in chronic hyponatremic rats than in normonatremic controls; that a rapid increase in plasma sodium and plasma osmolality causes a marked global increase in cerebral perfusion in both hyponatremic and normonatremic rats; and that disruption of BBB appears to be related to the subsequent development of brain demylenation. Given these findings, we have begun a series of experiments to study how alterations in BBB permeability and the changes in cerebral perfusion which follow rapid changes in plasma osmolality relate to the subsequent development of neurologic symptoms and brain demylenation which often follow rapid correction of hyponatremia. Specifically, we hope to identify the mechanisms responsible for the osmolar induced increase in cerebral perfusion, and to determine the mediators responsible for the changes in cerebral perfusion during correction of hyponatremia.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR003631-09
Application #
5224633
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
9
Fiscal Year
1996
Total Cost
Indirect Cost
Ramachandran, Suchitra; Meyer, Travis; Olson, Carl R (2016) Prediction suppression in monkey inferotemporal cortex depends on the conditional probability between images. J Neurophysiol 115:355-62
Meyer, Travis; Walker, Christopher; Cho, Raymond Y et al. (2014) Image familiarization sharpens response dynamics of neurons in inferotemporal cortex. Nat Neurosci 17:1388-94
Hall, Nathan; Colby, Carol (2014) S-cone visual stimuli activate superior colliculus neurons in old world monkeys: implications for understanding blindsight. J Cogn Neurosci 26:1234-56
Subramanian, Janani; Colby, Carol L (2014) Shape selectivity and remapping in dorsal stream visual area LIP. J Neurophysiol 111:613-27
Berdyyeva, Tamara K; Olson, Carl R (2014) Intracortical microstimulation of supplementary eye field impairs ability of monkeys to make serially ordered saccades. J Neurophysiol 111:1529-40
Meyer, Travis; Ramachandran, Suchitra; Olson, Carl R (2014) Statistical learning of serial visual transitions by neurons in monkey inferotemporal cortex. J Neurosci 34:9332-7
Hall, Nathan; Colby, Carol (2013) Psychophysical definition of S-cone stimuli in the macaque. J Vis 13:
Leathers, Marvin L; Olson, Carl R (2012) In monkeys making value-based decisions, LIP neurons encode cue salience and not action value. Science 338:132-5
Meyer, Travis; Olson, Carl R (2011) Statistical learning of visual transitions in monkey inferotemporal cortex. Proc Natl Acad Sci U S A 108:19401-6
Berdyyeva, Tamara K; Olson, Carl R (2011) Relation of ordinal position signals to the expectation of reward and passage of time in four areas of the macaque frontal cortex. J Neurophysiol 105:2547-59

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