Glutamate receptor antagonists and growth factors modulate dentate granule cell neurogenesis in organotypic, rat hippocampal slice cultures.
Generation of dentate granule cells and its modulation by glutamate receptor antagonists, growth factors and pilocarpine-induced seizure-like activity was investigated in rat hippocampal slice cultures derived from 1-week-old rats and grown for 2 weeks. Focussing on the dentate granule cell layer facing CA1 and the immediate subgranular zone, exposure for 3 days to the NMDA receptor blocking agents MK-801 (10 microM) or APV (25 microM) in the culture medium, increased the number of TOAD-64/Ulip/CRMP-4 (TUC-4)-positive cells as counted in the slice cultures at the end of the 3-day treatment period. Exposure to IGF-I (200 ng/ml) and EGF (20 ng/ml) also increased the number of TUC-4-positive cells. Combining APV with IGF-I/EGF had an additive effect. Similar results were obtained by 3 days treatment with the AMPA receptor antagonist CNQX (25 microM). Surprisingly, addition of 5 mM pilocarpine reduced the number of TUC-4-positive cells, just as combining pilocarpine with the neurogenesis-stimulating compounds, prevented or reduced the increase of TUC-4-positive cells. None of the treatments were found to induce dentate granule cell death within the observed period. Labeling of dividing cells by adding 5-bromo-2-deoxyuridine (BrdU) to the culture medium did not result in cells double-labeled with BrdU and TUC-4. The induced increase in TUC-4-positive cells therefore represent neuronal differentiation of existing neural precursor cells when investigated at the 3-day time point. We conclude that 3 days treatment of 2-week-old hippocampal slice cultures with IGF-I and EGF and NMDA and AMPA glutamate receptor antagonists increase granule cell neurogenesis from preexisting neural precursors.
Poulsen
Frantz Rom
FR
Anatomy and Neurobiology, Institute of Medical Biology, University of Southern Denmark, Winslowparken 21, DK-5000 Odense C, Denmark. fpoulsen@health.sdu.dk
Blaabjerg
Morten
M
Montero
Maria
M
Zimmer
Jens
J
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D018891:Dentate Gyrus / Q000166:cytology* / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D009924:Organ Culture Techniques; D010862:Pilocarpine; D051381:Rats; D017208:Rats, Wistar; D017470:Receptors, Glutamate / Q000187:drug effects / Q000378:metabolism*; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism
C449760:Dpysl3 protein, rat; D018691:Excitatory Amino Acid Antagonists; D009419:Nerve Tissue Proteins; D017470:Receptors, Glutamate; D010862:Pilocarpine; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I