TY - JOUR
T1 - Neuroinflammation alters voltage-dependent conductance in striatal astrocytes
AU - Karpuk, Nikolay
AU - Burkovetskaya, Maria
AU - Kielian, Tammy
N1 - Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2012/7/1
Y1 - 2012/7/1
N2 - Neuroinflammation has the capacity to alter normal central nervous system (CNS) homeostasis and function. The objective of the present study was to examine the effects of an inflammatory milieu on the electrophysiological properties of striatal astrocyte subpopulations with a mouse bacterial brain abscess model. Whole cell patch-clamp recordings were performed in striatal glial fibrillary acidic protein (GFAP)-green fluorescent protein (GFP)+ astrocytes neighboring abscesses at postinfection days 3 or 7 in adult mice. Cell input conductance (Gi) measurements spanning a membrane potential (Vm) surrounding resting membrane potential (RMP) revealed two prevalent astrocyte subsets. A1 and A2 astrocytes were identified by negative and positive Gi increments vs. Vm, respectively. A1 and A2 astrocytes displayed significantly different RMP, Gi, and cell membrane capacitance that were influenced by both time after bacterial exposure and astrocyte proximity to the inflammatory site. Specifically, the percentage of A1 astrocytes was decreased immediately surrounding the inflammatory lesion, whereas A2 cells were increased. These changes were particularly evident at postinfection day 7, revealing increased cell numbers with an outward current component. Furthermore, RMP was inversely modified in A1 and A2 astrocytes during neuroinflammation, and resting Gi was increased from 21 to 30 nS in the latter. In contrast, gap junction communication was significantly decreased in all astrocyte populations associated with inflamed tissues. Collectively, these findings demonstrate the heterogeneity of striatal astrocyte populations, which experience distinct electrophysiological modifications in response to CNS inflammation.
AB - Neuroinflammation has the capacity to alter normal central nervous system (CNS) homeostasis and function. The objective of the present study was to examine the effects of an inflammatory milieu on the electrophysiological properties of striatal astrocyte subpopulations with a mouse bacterial brain abscess model. Whole cell patch-clamp recordings were performed in striatal glial fibrillary acidic protein (GFAP)-green fluorescent protein (GFP)+ astrocytes neighboring abscesses at postinfection days 3 or 7 in adult mice. Cell input conductance (Gi) measurements spanning a membrane potential (Vm) surrounding resting membrane potential (RMP) revealed two prevalent astrocyte subsets. A1 and A2 astrocytes were identified by negative and positive Gi increments vs. Vm, respectively. A1 and A2 astrocytes displayed significantly different RMP, Gi, and cell membrane capacitance that were influenced by both time after bacterial exposure and astrocyte proximity to the inflammatory site. Specifically, the percentage of A1 astrocytes was decreased immediately surrounding the inflammatory lesion, whereas A2 cells were increased. These changes were particularly evident at postinfection day 7, revealing increased cell numbers with an outward current component. Furthermore, RMP was inversely modified in A1 and A2 astrocytes during neuroinflammation, and resting Gi was increased from 21 to 30 nS in the latter. In contrast, gap junction communication was significantly decreased in all astrocyte populations associated with inflamed tissues. Collectively, these findings demonstrate the heterogeneity of striatal astrocyte populations, which experience distinct electrophysiological modifications in response to CNS inflammation.
KW - Gap junction communication
KW - Hemichannels
KW - Whole cell patch clamp
UR - http://www.scopus.com/inward/record.url?scp=84863319545&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84863319545&partnerID=8YFLogxK
U2 - 10.1152/jn.01182.2011
DO - 10.1152/jn.01182.2011
M3 - Article
C2 - 22457466
AN - SCOPUS:84863319545
VL - 108
SP - 112
EP - 123
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 1
ER -