MAPK3 and concussion: mTBI reduced the phosphorylation of ERK1/2 and CREB, key signaling molecules downstream of synaptic NMDAR activation, consistent with previous findings in chronic TBI models [67,68,69,70] and as shown in Figure 4I. Exo70 overexpression restored the phosphorylation of these proteins, further supporting the idea that it promotes functional synaptic NMDAR signaling.