Endogenous neurotrophin-3 regulates short-term plasticity at lateral perforant path-granule cell synapses.


In the adult brain, neurotrophin-3 (NT-3) is mainly localized in dentate granule cells, and its expression is decreased by various stimuli, e.g., seizure activity. We have examined the role of endogenous NT-3 for excitatory synaptic transmission at lateral perforant path-dentate granule cell synapses using hippocampal slices from NT-3 knock-out (+/-) and wild-type (+/+) mice. Paired-pulse facilitation (PPF) and also short-term synaptic plasticity induced by a brief, high-frequency train of afferent stimulation were reduced, but the expression of long-term potentiation was not affected in the NT-3+/- mice. Incubation of the slices with recombinant NT-3 reversed the deficit in PPF through a mechanism requiring de novo protein synthesis, implying that the impaired short-term plasticity does not result from a developmental alteration. No changes of overall presynaptic release probability, measured by the progressive block of NMDA receptor-mediated synaptic currents by MK-801, or desensitization of AMPA receptors were detected. Because NT-3 expression is reduced after focal seizures, impaired short-term facilitation may represent a protective response that limits the propagation of epileptiform activity from the entorhinal cortex to the hippocampus.

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@article{Kokaia1998EndogenousNR, title={Endogenous neurotrophin-3 regulates short-term plasticity at lateral perforant path-granule cell synapses.}, author={M Kokaia and F Asztely and K Olofsdotter and C B Sindreu and D M Kullmann and O Lindvall}, journal={The Journal of neuroscience : the official journal of the Society for Neuroscience}, year={1998}, volume={18 21}, pages={8730-9} }