Functional synaptic projections onto subplate neurons in neonatal XXXX somatosensory cortex.

@entity1246 @entity18713 @entity1023 @entity140 @entity143 @entity35 @entity10640
Subplate neurons (SPn) play an important role in the formation of thalamocortical connections during early development and show glutamatergic and GABAergic spontaneous synaptic activity. We characterized these synaptic inputs by performing whole-cell recordings from SPn in somatosensory cortical slices of postnatal day 0-3 @entity35 . At -70 mV, electrical stimulation of the thalamocortical afferents elicited in 68% of the SPn a monosynaptic @entity1023 -sensitive postsynaptic current (PSC). These fast PSCs were mediated by @entity140 receptors, because they were prolonged by @entity10640 and blocked by @entity18713 . On membrane depolarization, thalamocortical stimulation elicited in 50% of the cells an additional slow monosynaptic component mediated by @entity143 receptors. Stimulation of the cortical plate evoked in 72% of SPn a monosynaptic @entity140 receptor-mediated PSC with an additional @entity143 component at depolarized membrane potentials and in 40% of the investigated cells polysynaptic responses, depending on @entity1246 (A) and @entity143 receptors. Stimulation of the subplate elicited in 67% of SPn a monosynaptic dual-component PSC mediated by @entity140 and @entity143 receptors activated at -70 mV and in 12% of SPn a monosynaptic single-component PSC mediated by @entity140 receptors with an additional @entity143 component activated at depolarized membrane potentials. A monosynaptic GABAergic response could be observed in 68% of SPn after stimulation of the subplate. In gramicidin-perforated patch recordings, bath application of @entity1246 caused membrane depolarization to -40 mV and elicited action potentials. These results demonstrate that SPn receive distinct functional synaptic inputs arising from the thalamus, cortical plate, and subplate, indicating that SPn are capable of integrating and processing information from cortical and subcortical regions.
