Ketamine (KT) or sleep deprivation (SD) induce common neuronal responses. (A) Bar graph depicts the relative expression of known core clock genes and NOTCH pathway genes measured by quantitative polymerase chain reaction (qPCR). Saline is indicated by gray bars, SD by pink bars, and KT by blue bars (*p < .05, **p < .01, t test, n = 4 per group). (B) Correlation plot represents microarray and qPCR data. (C) Theoretical diagram illustrates the effects of KT or SD on the modulation of the limbic cortex or anterior cingulate cortex (ACC) circadian clock and pathways involved in neuronal plasticity. These neuronal adaptations could potentially provide a mechanism for the initiation of rapid antidepressant effects.