Intranasal Oxytocin following Uncontrollable Stress Blocks Impairments in Hippocampal Plasticity and Recognition Memory in Stressed Rats

BACKGROUND: Nasal pretreatment with the neuropeptide oxytocin has been reported to prevent stress-induced impairments in hippocampal synaptic plasticity and spatial memory in rats. However, no study has asked if oxytocin application following a stress experience is effective in rescuing stress-induced impairments. METHODS: Synaptic plasticity was measured in hippocampal Schaffer collateral-CA1 synapses of rats subjected to uncontrollable stress; their cognitive function was examined using an object recognition task. RESULTS: Impaired induction of long-lasting, long-term potentiation by uncontrollable stress was rescued, as demonstrated both in rats and hippocampal slices. Intranasal oxytocin after experiencing uncontrollable stress blocked cognitive impairments in stressed rats and in stressed hippocampal slices treated with a perfused bath solution containing oxytocin. CONCLUSIONS: These results indicated that posttreatment with oxytocin after experiencing a stressful event can keep synaptic plasticity and cognition function intact, indicating the therapeutic potential of oxytocin for stress-related disorders, including posttraumatic stress disorder.