K(+) currents fail to change in reactive retinal glial cells in a mouse model of glaucoma.
OBJECTIVE
To investigate the membrane physiology of Müller glial cells from retinae of DBA/2J mice (which develop ocular hypertension) and of C57BL/6 control mice of different ages.


METHODS
Retinae were obtained at the ages of 3, 6, and 12 months from DBA/2J mice and from C57BL/6 controls. Immunohistochemistry was performed using antibodies against glial fibrillary acidic protein (GFAP). Whole-cell membrane currents, membrane potentials and capacitances were recorded from freshly isolated Müller cells.


RESULTS
Strong immunostaining for GFAP was found in Müller cells of 12-month-old DBA/2J mice, whereas only astrocytes were immunopositive in C57BL/6 retinae. No significant alterations of membrane currents or potentials of Müller cells from DBA/2J mice as compared to controls were observed at any age; however, the membrane capacitance was increased in Müller cells from DBA/2J mice at the age of 6 months.


CONCLUSIONS
Although Müller cells of DBA/2J mice display some symptoms of reactive gliosis, the lack of significant alterations of the membrane physiology confirm previous data demonstrating that these cells undergo a nonproliferative gliosis.
Department of Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Röntgenweg 11, 72076 Tübingen, Germany.
Sylvia
S
Bolz
Frank
F
Schuettauf
Julia E
JE
Fries
Sebastian
S
Thaler
Andreas
A
Reichenbach
Thomas
T
Pannicke
D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D005901:Glaucoma / Q000503:physiopathology*; D005904:Glial Fibrillary Acidic Protein; D005911:Gliosis / Q000503:physiopathology*; D008564:Membrane Potentials / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008856:Microscopy, Fluorescence; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009457:Neuroglia / Q000502:physiology*; D009798:Ocular Hypertension / Q000503:physiopathology; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000502:physiology*; D012160:Retina / Q000503:physiopathology*; D012162:Retinal Degeneration / Q000503:physiopathology*
D005904:Glial Fibrillary Acidic Protein; D009419:Nerve Tissue Proteins; D015221:Potassium Channels; C528900:glial fibrillary astrocytic protein, mouse