Distinct Translaminar Glutamatergic Circuits to GABAergic Interneurons in the Neonatal Auditory Cortex

Publication date: 9 May 2017
Source:Cell Reports, Volume 19, Issue 6
Author(s): Rongkang Deng, Joseph P.Y. Kao, Patrick O. Kanold
GABAergic activity is important in neocortical development and plasticity. Because the maturation of GABAergic interneurons is regulated by neural activity, the source of excitatory inputs to GABAergic interneurons plays a key role in development. We show, by laser-scanning photostimulation, that layer 4 and layer 5 GABAergic interneurons in the auditory cortex in neonatal mice (<P7) receive extensive translaminar glutamatergic input via NMDAR-only synapses. Extensive translaminar AMPAR-mediated input developed during the second postnatal week, whereas NMDAR-only presynaptic connections decreased. GABAergic interneurons showed two spatial patterns of translaminar connection: inputs originating predominantly from supragranular or from supragranular and infragranular layers, including the subplate, which relays early thalamocortical activity. Sensory deprivation altered the development of translaminar inputs. Thus, distinct translaminar circuits to GABAergic interneurons exist throughout development, and the maturation of excitatory synapses is input-specific. Glutamatergic signaling from subplate and intracortical sources likely plays a role in the maturation of GABAergic interneurons.

Graphical abstract

Teaser

Excitatory inputs are important for the development of GABAergic neurons. Deng et al. demonstrate that developing GABAergic neurons receive extensive early translaminar NMDAR-only inputs, including deep thalamorecipient layers, and that sensory experience can alter the maturation of these circuits. These results reveal the circuits controlling the development of GABAergic neurons.


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