Temporally dissociable effects of ketamine on neuronal discharge and gamma oscillations in rat thalamo-cortical networks.
Neuropharmacology July 15, 2018 Maria Amat-Foraster, Anders A Jensen, Niels Plath et al.
Sub-anesthetic doses of ketamine (1, 2, and 5 mg/kg intravenously) decreased the firing rate of neurons in the reticular thalamic nucleus, mediodorsal and centromedial thalamic nuclei, and layer VI of the medial prefrontal cortex in anesthetized male Wistar rats. Ketamine also reduced low-frequency oscillations across these areas while increasing gamma oscillations in the medial prefrontal cortex and mediodorsal/centromedial thalamic nuclei. Lower doses (0.25 and 0.5 mg/kg) had no effect. Unlike phencyclidine, ketamine's inhibition of reticular thalamic nucleus neurons did not disinhibit excitatory neurons in other areas, likely due to concurrent NMDA receptor blockade there. The early transient inhibition may relate to psychotomimetic effects, while prolonged gamma increases may underlie antidepressant action.