RT Journal Article
SR Electronic
T1 Differential Signaling to Subplate Neurons by Spatially Specific Silent Synapses in Developing Auditory Cortex
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 8855
OP 8864
DO 10.1523/JNEUROSCI.0233-14.2014
VO 34
IS 26
A1 Xiangying Meng
A1 Joseph P.Y. Kao
A1 Patrick O. Kanold
YR 2014
UL http://www.jneurosci.org/content/34/26/8855.abstract
AB Subplate neurons (SPNs) form one of the earliest maturing circuits in the cerebral cortex and are crucial to cortical development. In addition to thalamic inputs, subsets of SPNs receive excitatory AMPAR-mediated inputs from the developing cortical plate in the second postnatal week. Functionally silent (non-AMPAR-mediated) excitatory synapses exist in several systems during development, and the existence of such inputs can precede the appearance of AMPAR-mediated synapses. Because SPNs receive inputs from presynaptic cells in different cortical layers, we investigated whether AMPAR-mediated and silent synapses might originate in different layers. We used laser-scanning photostimulation in acute thalamocortical slices of mouse auditory cortex during the first 2 postnatal weeks to study the spatial origin of silent synapses onto SPNs. We find that silent synapses from the cortical plate are present on SPNs and that they originate from different cortical locations than functional (AMPAR-mediated) synapses. Moreover, we find that SPNs can be categorized based on the spatial pattern of silent and AMPAR-mediated connections. Because SPNs can be activated at young ages by thalamic inputs, distinct populations of cortical neurons at young ages have the ability to signal to SPNs depending on the activation state of SPNs. Because during development intracortical circuits are spontaneously active, our results suggest that SPNs might integrate ascending input from the thalamus with spontaneously generated cortical activity patterns. Together, our results suggest that SPNs are an integral part of the developing intracortical circuitry and thereby can sculpt thalamocortical connections.