Temporally dissociable effects of ketamine on neuronal discharge and gamma oscillations in rat thalamo-cortical networks

As observed for PCP, ketamine markedly inhibited the activity of RtN neurons. However, unlike PCP, this effect did not translate into a disinhibition of MD/CM and mPFC excitatory neurons, possibly due to a more potent and simultaneous blockade of NMDA-Rs by ketamine in MD/CM and mPFC neurons. Hence, the present in vivo results show that ketamine evokes an early transient inhibition of neuronal discharge in thalamo-cortical networks, following its rapid pharmacokinetics, which is likely associated to its psychotomimetic effects. The prolonged increase in gamma oscillations may underlie its antidepressant action.