(A) FUNCAT was used to measure rates of protein synthesis in cortical neurons. AHA signal intensity in MAP2-stained dendrites reveals relative levels of new protein synthesized over a 6-hr period. Examples of 14 DIV cortical neurons from GluN2BKO and 2B→2A as well as WT control neurons treated with the protein synthesis inhibitor anisomycin (Aniso) or transcription inhibitor actinomycin-D (ActD). (B) Combined data show significant increase in protein synthesis rates in GluN2BKO and 2B→2A neurons and suppression of basal levels by anisomycin. (C) Combined data showing the significant increase in protein synthesis rates evoked by ketamine, occlusion of this increase in 2BΔCtx and sensitivity of the AHA signal to rapamycin in 2BΔCtx neurons. (D–H) Cortical synaptoneurosomes from animals following saline or ketamine injection. Western blot analysis showed the presence of mTOR in synaptoneurosomes as well as basal levels of phosphorylated protein (p-mTOR) and expression of BDNF, Rheb, and the synaptic proteins, SAP-102, GluA1, and GluA2. (D) Expression levels, and phosphorylation status of mTOR, following ketamine injection (1, 3, and 6 hr post injection) compared to saline-injected controls. (E) p-mTOR measured relative to total mTOR levels demonstrating time-dependent changes in phosphorylation status in response to ketamine. (F) Synaptic protein expression is shown in relation to levels of actin at 1, 3, or 6 hr post ketamine normalized to saline-injected controls. Increased levels of GluA1, SAP102, and BDNF as well as decreased rheb expression seen at 3 and 6 hr post injection. (G) Example of western blots at 6 hr post-injection for both control and 2BΔCtx genotypes. (H) Quantification of the data showed significant increases in synaptic proteins in response to ketamine (k), consistent with (A–C), but also revealing occlusion of these increases in SAP-102, GluA1 and p-mTOR in 2BΔCtx animals. Data values are means ± sem. **p < 0.01; ***p < 0.001 t test with respect to WT; n.c. = no significant change.