Effects of brain-derived neurotrophic factor (BDNF) on activity mediated by NMDA receptors in rat spinal cord cultures.
Brain-derived neurotrophic factor (BDNF) is involved in the differentiation and the survival of neurons. It has also been shown to be associated with the regrowth of neurons of damaged spinal cord and the modulation of ionic currents by acting on sodium channels and NMDA receptors through tyrosine kinase B (TrkB) receptors. We investigated the effects of BDNF on rhythm generation induced by disinhibition in dissociated cultures from embryonic rat spinal cord (E14), with extracellular multisite recordings (MultiElectrode Arrays, MEAs) or intracellular patch-clamp recordings. Exogenous BDNF had only minor effects on the bursting by increasing the activity during the burst. This increase of activity is suggested to be mediated by a potentiation of the postsynaptic NMDA receptors because it has been found that BDNF potentiates the NMDA-evoked depolarization in cultures incubated with BDNF for 10 min. Possible direct effects of BDNF on sodium channels were also investigated by local application of BDNF to the soma of patched neurons but no depolarization was observed. Long-term application of BDNF strongly decreased the activity during the burst and also the number of active electrodes, possibly due to a decrease in network density.
Legrand
Jean-Christophe
JC
Department of Physiology, University of Bern, Bühlplatz 5, CH-3012 Bern, Switzerland.
Darbon
Pascal
P
Streit
Jürg
J
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D019208:Brain-Derived Neurotrophic Factor / Q000008:administration & dosage* / Q000276:immunology; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004622:Embryo, Mammalian; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009924:Organ Culture Techniques; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology* / Q000187:drug effects; D013779:Tetrodotoxin / Q000494:pharmacology; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
D000779:Anesthetics, Local; D000906:Antibodies; D019208:Brain-Derived Neurotrophic Factor; D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D013779:Tetrodotoxin; D016202:N-Methylaspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; C056639:2-amino-5-phosphopentanoic acid; D014633:Valine