Presynaptic plasticity at two giant auditory synapses in normal and deaf mice Export

@article{citeulike:5284094, abstract = {10.1113/jphysiol.2004.066662 Large calyceal synapses are often regarded as simple relay points, built for high-fidelity and high-frequency synaptic transmission and a minimal requirement for synaptic plasticity, but this view is oversimplified. Calyceal synapses can exhibit surprising activity-dependent developmental plasticity. Here we compare basal synaptic transmission and activity-dependent plasticity at two stereotypical calyceal synapses in the auditory pathway, the endbulb and the calyx of Held. Basal synaptic transmission was more powerful at the calyx than the endbulb synapse: the amplitude of evoked AMPA receptor-mediated excitatory postsynaptic currents (eEPSCs) was significantly greater at the calyx, as were the release probability, and the number of release sites. The quantal amplitude was smaller at the calyx, consistent with the smaller amplitude of spontaneous miniature EPSCs at this synapse. High-frequency trains of stimuli revealed that the calyx had a larger readily releasable pool of vesicles (RRP), less tetanic depression and less asynchronous transmitter release. Activity-dependent synaptic plasticity was assessed in congenitally deaf mutant mice (). Previously we showed that a lack of synaptic activity in deaf mice increases synaptic strength at the endbulb of Held via presynaptic mechanisms. In contrast, we have now found that deafness does not affect synaptic transmission at the calyx synapse, as eEPSC and mEPSC amplitude, release probability, number of release sites, size of RRP, tetanic depression and asynchronous release were unchanged compared to normal mice. Synaptic transmission at the calyx synapse is more powerful and has less capacity for developmental plasticity compared to the endbulb synapse.}, author = {Oleskevich, S. and Youssoufian, M. and Walmsley, B.}, citeulike-article-id = {5284094}, citeulike-linkout-0 = {http://dx.doi.org/10.1113/jphysiol.2004.066662}, citeulike-linkout-1 = {http://jphysiol.highwire.org/content/560/3/709.abstract}, citeulike-linkout-2 = {http://jphysiol.highwire.org/content/560/3/709.full.pdf}, citeulike-linkout-3 = {http://view.ncbi.nlm.nih.gov/pubmed/15331689}, citeulike-linkout-4 = {http://www.hubmed.org/display.cgi?uids=15331689}, day = {1}, doi = {10.1113/jphysiol.2004.066662}, journal = {The Journal of Physiology}, keywords = {amplitude, calyx, comparison, constant, endbulb, epsc, held, synapse, time}, month = {November}, number = {3}, pages = {709--719}, posted-at = {2009-07-27 20:59:45}, priority = {2}, title = {Presynaptic plasticity at two giant auditory synapses in normal and deaf mice}, url = {http://dx.doi.org/10.1113/jphysiol.2004.066662}, volume = {560}, year = {2004} }

TY - JOUR ID - citeulike:5284094 L3 - citeulike-article-id:5284094 N2 - 10.1113/jphysiol.2004.066662 Large calyceal synapses are often regarded as simple relay points, built for high-fidelity and high-frequency synaptic transmission and a minimal requirement for synaptic plasticity, but this view is oversimplified. Calyceal synapses can exhibit surprising activity-dependent developmental plasticity. Here we compare basal synaptic transmission and activity-dependent plasticity at two stereotypical calyceal synapses in the auditory pathway, the endbulb and the calyx of Held. Basal synaptic transmission was more powerful at the calyx than the endbulb synapse: the amplitude of evoked AMPA receptor-mediated excitatory postsynaptic currents (eEPSCs) was significantly greater at the calyx, as were the release probability, and the number of release sites. The quantal amplitude was smaller at the calyx, consistent with the smaller amplitude of spontaneous miniature EPSCs at this synapse. High-frequency trains of stimuli revealed that the calyx had a larger readily releasable pool of vesicles (RRP), less tetanic depression and less asynchronous transmitter release. Activity-dependent synaptic plasticity was assessed in congenitally deaf mutant mice (). Previously we showed that a lack of synaptic activity in deaf mice increases synaptic strength at the endbulb of Held via presynaptic mechanisms. In contrast, we have now found that deafness does not affect synaptic transmission at the calyx synapse, as eEPSC and mEPSC amplitude, release probability, number of release sites, size of RRP, tetanic depression and asynchronous release were unchanged compared to normal mice. Synaptic transmission at the calyx synapse is more powerful and has less capacity for developmental plasticity compared to the endbulb synapse. IS - 3 JF - The Journal of Physiology EP - 719 TI - Presynaptic plasticity at two giant auditory synapses in normal and deaf mice VL - 560 SP - 709 KW - amplitude KW - calyx KW - comparison KW - constant KW - endbulb KW - epsc KW - held KW - synapse KW - time AU - Oleskevich, S AU - Youssoufian, M AU - Walmsley, B PY - 2004/11/01/ UR - http://dx.doi.org/10.1113/jphysiol.2004.066662 ER -