Prolonged ketamine exposure induces enhanced excitatory GABAergic synaptic activity in the anterior cingulate cortex of neonatal rats

•Hyperexcitability following repeated ketamine exposure was tested in neonatal neurons.•Cl− efflux due to increased GABAA channel currents contributed to hyperexcitability.•These ketamine-induced events could be blocked by inhibition of NKCC1.•Higher vulnerable to ketamine-induced neurotoxicity in the developing brain is linked.