Plasticity of GABAergic synapses in developing networks

Abstract

Event Abstract Back to Event Plasticity of GABAergic synapses in developing networks Mu-Ming Poo1* 1 University of California, Department of Molecular and Cell Biology, United States Activity-induced long-term modification of developing GABAergic synapses is an integral part of developmental refinement of neural circuits by electrical activities. Such modification may occur at both pre- and postsynaptic sites, as will be illustrated here by two different examples. First, in the developing Xenopus retinotectal system, we found that repetitive light stimuli or theta burst stimulation (TBS) of the optic nerve could induce long-term potentiation (LTP) of glutamatergic inputs but long-term depression (LTD) of GABAergic inputs to the same tectal neuron. The GABAergic LTD was due to a reduction in presynaptic GABA release and required activation of presynaptic NMDA (N-methyl-D-aspartate) receptors (NMDARs) and coincident highb-level GABAergic activity. Thus, the presynaptic NMDAR may function as a coincidence detector for adjacent glutamatergic and GABAergic activities, leading to coordinated synaptic modification by sensory experience. Second, in the developing rat hippocampus, repetitive coincident pre- and postsynaptic spiking can results in either LTP or LTD of the GABAergic synapses - spiking at 20-50 Hz resulted in synaptic potentiation, whereas spiking at 5 Hz led to synaptic depression. The potentiation was abolished by blocking GABA(B) receptors (GABA(B)Rs), whereas the depression was independent of GABA(B)R activation and could be converted to potentiation by elevating GABA(B)R activity. The potentiation could be attributed to a local postsynaptic increase in Na(+)/K(+)/2Cl(-) co-transporter activity near activated synapses. Since activation of GABA(B)Rs is frequency-dependent, these results indicate that postsynaptic GABA(B)R activation mediates frequency-dependent potentiation of developing GABAergic synapses. Conference: INMED Satellite Conference of SFN - Neuroscience 2009, Multiple Facets of GABA in Brain Development, Chicago, United States, 16 Oct - 16 Oct, 2009. Presentation Type: Oral Presentation Topic: Abstracts Citation: Poo M (2009). Plasticity of GABAergic synapses in developing networks. Conference Abstract: INMED Satellite Conference of SFN - Neuroscience 2009, Multiple Facets of GABA in Brain Development. doi: 10.3389/conf.neuro.03.2009.13.010 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Jul 2009; Published Online: 23 Jul 2009. * Correspondence: Mu-Ming Poo, University of California, Department of Molecular and Cell Biology, Berkeley, United States, mpoo@uclink.berkeley.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Mu-Ming Poo Google Mu-Ming Poo Google Scholar Mu-Ming Poo PubMed Mu-Ming Poo Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.