Anaesthesia induces neuronal insulin resistance. Mice were injected i.p. with either urethane or ketamine/Xylazine (K/X). Half of the K/X group were given insulin by icv injection, the other half received saline, 30 mins prior to sacrifice and rapid removal and dissection of the brain. Control animals were sacrificed without anaesthesia or icv injection. Equal amounts of cortical protein were subjected to western blot using the specific antibodies shown (A-representative blots), and results from 4 animals in each treatment group were quantified by densitometry (B). The mean ± SD, relative to the control animals, is shown. Significant differences between control and each treatment group are given, *p < 0.05, **p < 0.005, ns, not significant. Body temperature of all animals during anaesthesia was monitored and is presented as mean ± SD (C).