Resilience and reduced c-Fos expression in P2X7 receptor knockout mice exposed to repeated forced swim test

▶P2X7 knockout mice exhibited an antidepressant-like phenotype. ▶High levels of immobility did not develop in P2X7 mice with repeated forced swims. ▶Repeated stress did not increase c-Fos in the hippocampus and amygdala of P2X7 mice. ▶P2X7 mice displayed decreased locomotor activity in tests of anxiety. ▶Anxiety measures appear non-specific in P2X7 knockout mice.