Neurosteroids modulate the reaction of astroglia to high extracellular potassium levels

Glia
S Del CerroL M Garcia-Segura

Abstract

The extracellular concentration of potassium ([K+]o) in brain tissue is modified by neuronal activity and is increased under several pathological conditions. The influence of neurosteroids on the astroglia response to high [K+]o was assessed on cultured slices from rat hippocampus. Exposure to [K+]o above physiological (3 mM) levels resulted in the progressive appearance of cell processes immunoreactive for glial fibrillary acidic protein (GFAP). The maximal effect was observed at 50 mM [K+]o, and further increases of [K+]o did not increase the extension of GFAP-immunoreactive processes. The effect was observed as early as 10 min after increasing [K+]o, was independent of new protein synthesis, and was reversible, reaching control conditions by 15 h after resetting [K+]o to physiological levels. Gonadal hormones and neurosteroids had prominent and variable effects on the stimulatory influence of high [K+]o on astroglia morphology. At physiological [K+]o, 17beta-estradiol and pregnenolone, as well as its sulfate derivative, increased the extension of GFAP-immunoreactive processes. However, at high [K+]o, testosterone, pregnenolone, and dehydroepiandrosterone and its sulfate derivative decreased the extension of GFAP-immunoreacti...Continue Reading

Citations

Sep 5, 2002·The Journal of Comparative Neurology·Daniel García-OvejeroLydia L Doncarlos
Aug 29, 2001·Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism·L VargováE Syková
Apr 27, 2005·Brain Research. Brain Research Reviews·Daniel Garcia-OvejeroLuis M Garcia-Segura
Jun 27, 2006·Experimental Neurology·Sarah M CutlerDonald G Stein
Aug 15, 2006·Glia·Luis M Garcia-Segura, Roberto C Melcangi
Sep 13, 2016·Frontiers in Neuroscience·Richard J ServatiusKevin C H Pang

❮ Previous
Next ❯

Related Concepts

Related Feeds

Astrocytes

Astrocytes are glial cells that support the blood-brain barrier, facilitate neurotransmission, provide nutrients to neurons, and help repair damaged nervous tissues. Here is the latest research.