De novo synaptogenesis induced by GABA in the developing mouse cortex

WC Oh, S Lutzu, PE Castillo, HB Kwon - Science, 2016 - science.org
Science, 2016science.org
Dendrites of cortical pyramidal neurons contain intermingled excitatory and inhibitory
synapses. We studied the local mechanisms that regulate the formation and distribution of
synapses. We found that local γ-aminobutyric acid (GABA) release on dendrites of mouse
cortical layer 2/3 pyramidal neurons could induce gephyrin puncta and dendritic spine
formation via GABA type A receptor activation and voltage-gated calcium channels during
early postnatal development. Furthermore, the newly formed inhibitory and excitatory …
Dendrites of cortical pyramidal neurons contain intermingled excitatory and inhibitory synapses. We studied the local mechanisms that regulate the formation and distribution of synapses. We found that local γ-aminobutyric acid (GABA) release on dendrites of mouse cortical layer 2/3 pyramidal neurons could induce gephyrin puncta and dendritic spine formation via GABA type A receptor activation and voltage-gated calcium channels during early postnatal development. Furthermore, the newly formed inhibitory and excitatory synaptic structures rapidly gained functions. Bidirectional manipulation of GABA release from somatostatin-positive interneurons increased and decreased the number of gephyrin puncta and dendritic spines, respectively. These results highlight a noncanonical function of GABA as a local synaptogenic element shaping the early establishment of neuronal circuitry in mouse cortex.
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