Low-dose ketamine changes stress-related brain and hormone responses in specific areas of rats

Subanesthetic ketamine (15 mg/kg) reduces immobility in the tail suspension test and attenuates the stress-induced increase in plasma corticosterone levels.

• Ketamine may modulate the stress-response network in a state-dependent manner.
• Neuronal activation patterns in response to ketamine varied by brain region and stress context.
• Ketamine selectively activated neuronal populations in the prefrontal cortex while enhancing stress-induced activation in the hippocampus and dorsal raphe nucleus.
• In contrast, it suppressed hyperactivation in the amygdala during stress.
• The presence of an acute stressor significantly influences ketamine's effects on the stress-response system.

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