title: BDNF and NT-3 increase excitatory input connectivity in rat hippocampal cultures.
abstract: The neurotrophic factors brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) have been shown to promote excitatory and inhibitory synapse development. However, a quantitative analysis of their influence on connectivity has proven in general difficult to achieve. In this work we use a novel experimental approach based on percolation concepts that provides a quantification of the average number of connections per neuron. In combination with electrophysiological measurements, we characterize the changes in network connectivity induced by BDNF and NT-3 in rat hippocampal cultures. We show that, on the one hand, BDNF and NT-3 accelerate the maturation of connectivity in the network by about 17 h. On the other hand, BDNF and NT-3 increase the number of excitatory input connections by a factor of about two, but without modifying the number of inhibitory input connections. This scenario of a dominant effect on the excitation is supported by the analysis of spontaneous population bursts in cultures treated with either BDNF or NT-3, which show burst amplitudes that are insensitive to the blockade of inhibition. A leaky integrate-and-fire model reproduces the experimental results well.
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, 76100 Israel.
authors.forename: Shimshon
authors.initials: S
authors.lastname: Jacobi
authors.forename: Jordi
authors.initials: J
authors.lastname: Soriano
authors.forename: Menahem
authors.initials: M
authors.lastname: Segal
authors.forename: Elisha
authors.initials: E
authors.lastname: Moses
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D004594:Electrophysiology; D005456:Fluorescent Dyes; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007202:Indicators and Reagents; D008959:Models, Neurological; D009414:Nerve Growth Factors / Q000494:pharmacology; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology*; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D020933:Neurotrophin 3 / Q000494:pharmacology*; D051381:Rats; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013569:Synapses / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D009414:Nerve Growth Factors; D020933:Neurotrophin 3; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D002118:Calcium