Plasticity Related Gene 1 Affects Mouse Barrel Cortex Function via Strengthening of Glutamatergic Thalamocortical Transmission
Plasticity related gene 1 (PRG 1) is a brain specific protein that modulates glutamatergic synaptic transmission. Here we investigated the functional role of PRG 1 in adolescent and adult mouse barrel cortex both in vitro and in vivo. Compared with wild type (WT) animals, PRG 1 deficient (KO) mice showed specific behavioral deficits in tests assessing sensorimotor integration and whisker based sensory discrimination as shown in the beam balance/walking test and sandpaper tactile discrimination test, respectively. At P25 31, spontaneous network activity in the barrel cortex in vivo was higher in KO mice compared with WT littermates, but not at P16 19. At P16 19, sensory evoked cortical responses in vivo elicited by single whisker stimulation were comparable in KO and WT mice. In contrast, at P25 31 evoked responses were smaller in amplitude and longer in duration in WT animals, whereas KO mice revealed no such developmental changes. In thalamocortical slices from KO mice, spontaneous activity was increased already at P16 19, and glutamatergic thalamocortical inputs to Layer 4 spiny stellate neurons were potentiated. We conclude that genetic ablation of PRG 1 modulates already at P16 19 spontaneous and evoked excitability of the barrel cortex, including enhancement of thalamocortical glutamatergic inputs to Layer 4, which distorts sensory processing in adulthood.
Cerebral cortex