Functional maturation of isolated neural progenitor cells from the adult rat hippocampus.
Although neural progenitor cells (NPCs) may provide a source of new neurons to alleviate neural trauma, little is known about their electrical properties as they differentiate. We have previously shown that single NPCs from the adult rat hippocampus can be cloned in the presence of heparan sulphate chains purified from the hippocampus, and that these cells can be pushed into a proliferative phenotype with the mitogen FGF2 [Chipperfield, H., Bedi, K.S., Cool, S.M. & Nurcombe, V. (2002) Int. J. Dev. Biol., 46, 661-670]. In this study, the active and passive electrical properties of both undifferentiated and differentiated adult hippocampal NPCs, from 0 to 12 days in vitro as single-cell preparations, were investigated. Sparsely plated, undifferentiated NPCs had a resting membrane potential of approximately -90 mV and were electrically inexcitable. In > 70%, ATP and benzoylbenzoyl-ATP evoked an inward current and membrane depolarization, whereas acetylcholine, noradrenaline, glutamate and GABA had no detectable effect. In Fura-2-loaded undifferentiated NPCs, ATP and benzoylbenzoyl-ATP evoked a transient increase in the intracellular free Ca(2+) concentration, which was dependent on extracellular Ca(2+) and was inhibited reversibly by pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid (PPADS), a P2 receptor antagonist. After differentiation, NPC-derived neurons became electrically excitable, expressing voltage-dependent TTX-sensitive Na(+) channels, low- and high-voltage-activated Ca(2+) channels and delayed-rectifier K(+) channels. Differentiated cells also possessed functional glutamate, GABA, glycine and purinergic (P2X) receptors. Appearance of voltage-dependent and ligand-gated ion channels appears to be an important early step in the differentiation of NPCs.
Hogg
Ron C
RC
School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia.
Chipperfield
Hiram
H
Whyte
Kathryn A
KA
Stafford
Mark R
MR
Hansen
Mitchell A
MA
Cool
Simon M
SM
Nurcombe
Victor
V
Adams
David J
DJ
D000818:Animals; D001464:Barium / Q000494:pharmacology; D015153:Blotting, Western / Q000379:methods; D002118:Calcium / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D004347:Drug Interactions; D004553:Electric Conductivity; D005455:Fluorescent Antibody Technique / Q000379:methods; D016257:Fura-2 / Q000378:metabolism; D019922:GAP-43 Protein / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology*; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009474:Neurons / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000819:agonists / Q000037:antagonists & inhibitors / Q000494:pharmacology; D018408:Patch-Clamp Techniques / Q000379:methods; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism / Q000494:pharmacology; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058476:Receptors, Purinergic P2X2; D058486:Receptors, Purinergic P2X7; D012964:Sodium / Q000378:metabolism; D013234:Stem Cells / Q000502:physiology*; D013997:Time Factors
D019922:GAP-43 Protein; D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D018377:Neurotransmitter Agents; C546403:P2rx2 protein, rat; C546470:P2rx7 protein, rat; D010975:Platelet Aggregation Inhibitors; D058919:Purinergic P2 Receptor Antagonists; D018048:Receptors, Purinergic P2; D058476:Receptors, Purinergic P2X2; D058486:Receptors, Purinergic P2X7; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D001464:Barium; D011732:Pyridoxal Phosphate; D012964:Sodium; D011188:Potassium; D002118:Calcium; D016257:Fura-2