Functional and molecular analysis of GABA receptors in human midbrain-derived neural progenitor cells.
GABA(A) receptor function is involved in regulating proliferation, migration, and differentiation of rodent neural progenitor cells (NPCs). However, little is known about the molecular composition and functional relevance of GABA(A) receptors in human neural progenitors. Here, we investigated human fetal midbrain-derived NPCs in respect to their GABA(A) receptor function and subunit expression using electrophysiology, calcium imaging, and quantitative real-time PCR. Whole-cell recordings of ligand- and voltage-gated ion channels demonstrate the ability of NPCs to generate action potentials and to express functional GABA(A) receptors after differentiation for 3 weeks in vitro. Pharmacological and molecular characterizations indicate a predominance of GABA(A) receptor heteromers containing subunits alpha2, beta1, and/or beta3, and gamma. Intracellular Ca(2+) measurements and the expression profile of the Na(+)-K(+)-Cl(-) co-transporter 1 and the K(+)-Cl(-) co-transporter 2 in differentiated NPCs suggest that GABA evokes depolarizations mediated by GABA(A) receptors. These data indicate that NPCs derived from human fetal midbrain tissue acquire essential GABA(A) receptor properties during neuronal maturation in vitro.
Wegner
Florian
F
Department of Neurology, University of Leipzig, Leipzig, Germany. fwegner@trm.uni-leipzig.de
Kraft
Robert
R
Busse
Kathy
K
Härtig
Wolfgang
W
Schaarschmidt
Grit
G
Schwarz
Sigrid C
SC
Schwarz
Johannes
J
Hevers
Wulf
W
D002118:Calcium; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004307:Dose-Response Relationship, Radiation; D004558:Electric Stimulation / Q000379:methods; D053686:Fetal Stem Cells / Q000187:drug effects / Q000502:physiology*; D018682:GABA Agents / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007211:Indoles; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D008636:Mesencephalon / Q000166:cytology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods; D026902:Potassium Channel Blockers / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D018079:Receptors, GABA / Q000145:classification / Q000235:genetics / Q000502:physiology*; D026941:Sodium Channel Blockers / Q000494:pharmacology; D019789:Tetraethylammonium / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D018682:GABA Agents; D007211:Indoles; D026902:Potassium Channel Blockers; D012333:RNA, Messenger; D018079:Receptors, GABA; D026941:Sodium Channel Blockers; D013779:Tetrodotoxin; C007293:DAPI; D005680:gamma-Aminobutyric Acid; D019789:Tetraethylammonium; D014446:Tyrosine 3-Monooxygenase; D002118:Calcium