A presynaptic kainate receptor is involved in regulating the dynamic properties of thalamocortical synapses during development

Previous studies have shown that pharmacological activation of presynaptic kainate receptors at glutamatergic synapses facilitates or depresses transmission in a dose-dependent manner. However, the only synaptically activated kainate autoreceptor described to date is facilitatory. Here, we describe a kainate autoreceptor that depresses synaptic transmission. This autoreceptor is present at developing thalamocortical synapses in the barrel cortex, specifically regulates transmission at frequencies corresponding to those observed in vivo during whisker activation, and is developmentally down regulated during the first postnatal week. This receptor may, therefore, limit the transfer of high-frequency activity to the developing cortex, the loss of which mechanism may be important for the maturation of sensory processing.