Type A GABA-Receptor-Dependent Synaptic Transmission Sculpts Dendritic Arbor Structure inXenopusTadpolesIn Vivo

• DOI: 10.1523/jneurosci.5331-08.2009
• Publication Date: 2009-04-15T17:38:43Z
• Authors: Wanhua Shen; Jorge Santos Da S...; Haiyan He; Hollis T. Cline
• Keywords: Neuropil; Gephyrin; GABA transporter

The emergence of dendritic arbor structure in vivo depends on synaptic inputs. We tested whether inhibitory GABAergic transmission regulates Xenopus optic tectal cell development by expressing a peptide corresponding to an intracellular loop (ICL) the gamma2 subunit type A GABA receptors (GABA(A)R), which is required anchor GABA(A) postsynaptic scaffold. Enhanced green fluorescent protein (EGFP)-tagged ICL (EGFP-ICL) was distributed punctate pattern at putative synapses, identified vesicular transporter immunoreactive puncta. expression completely blocked GABA(A)R-mediated 36% transfected neurons and significantly reduced currents relative AMPA receptor-mediated remaining without altering release probability or neuronal excitability. Further analysis ICL-expressing with residual inputs showed that capacity benzodiazepine enhance responses neurons, indicating they were likely depleted subunit-containing GABA(A)R. Neurons mutant form comparable controls. In time-lapse images have more sparsely branched arbors, expand over larger neuropil areas than EGFP-expressing control neurons. Analysis branch dynamics indicated affected growth reducing rates addition. Furthermore, we found decreasing visual experience dependent structural plasticity. Our findings establish essential role for regulation plasticity vivo.