Rapid BDNF-induced retrograde synaptic modification in a developing retinotectal system.
In cultures of hippocampal neurons, induction of long-term synaptic potentiation or depression by repetitive synaptic activity is accompanied by a retrograde spread of potentiation or depression, respectively, from the site of induction at the axonal outputs to the input synapses on the dendrites of the presynaptic neuron. We report here that rapid retrograde synaptic modification also exists in an intact developing retinotectal system. Local application of brain-derived neurotrophic factor (BDNF) to the Xenopus laevis optic tectum, which induced persistent potentiation of retinotectal synapses, led to a rapid modification of synaptic inputs at the dendrites of retinal ganglion cells (RGCs), as shown by a persistent enhancement of light-evoked excitatory synaptic currents and spiking activity of RGCs. This retrograde effect required TrkB receptor activation, phospholipase Cgamma activity and Ca2+ elevation in RGCs, and was accounted for by a selective increase in the number of postsynaptic AMPA-subtype glutamate receptors at RGC dendrites. Such retrograde information flow in the neuron allows rapid regulation of synaptic inputs at the dendrite in accordance to signals received at axon terminals, a process reminiscent of back-propagation algorithm for learning in neural networks.
Du
Jiu-Lin
JL
Division of Neurobiology, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA.
Poo
Mu-Ming
MM
D000200:Action Potentials / Q000187:drug effects / Q000528:radiation effects; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D003712:Dendrites / Q000187:drug effects / Q000528:radiation effects; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D008027:Light; D017774:Long-Term Potentiation / Q000187:drug effects; D036881:Long-Term Synaptic Depression / Q000187:drug effects; D051966:Phospholipase C gamma; D010775:Photic Stimulation; D020813:Receptor, trkB / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D013477:Superior Colliculi / Q000166:cytology / Q000187:drug effects* / Q000502:physiology* / Q000528:radiation effects; D013569:Synapses / Q000187:drug effects* / Q000502:physiology* / Q000528:radiation effects; D010738:Type C Phospholipases / Q000378:metabolism; D014982:Xenopus laevis
D019208:Brain-Derived Neurotrophic Factor; D020813:Receptor, trkB; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D002118:Calcium