Dysbalance of astrocyte calcium under hyperammonemic conditions.

ABSTRACT: Increased brain ammonium (NH4(+)/NH3) plays a central role in the manifestation of hepatic encephalopathy (HE), a complex syndrome associated with neurological and psychiatric alterations, which is primarily a disorder of astrocytes. Here, we analysed the influence of NH4(+)/NH3 on the calcium concentration of astrocytes in situ and studied the underlying mechanisms of NH4(+)/NH3-evoked calcium changes, employing fluorescence imaging with Fura-2 in acute tissue slices derived from different regions of the mouse brain. In the hippocampal stratum radiatum, perfusion with 5 mM NH4(+)/NH3 for 30 minutes caused a transient calcium increase in about 40% of astrocytes lasting about 10 minutes. Furthermore, the vast majority of astrocytes (∼ 90%) experienced a persistent calcium increase by ∼ 50 n

SUBMITTER: Haack N 

PROVIDER: S-EPMC4143319 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature