Kainic acid upregulates uncoupling protein-2 mRNA expression in the mouse brain

Intraperitoneal injection of kainic acid (KA) in C57BL/6J and 129T2SvEmsJ mice led to a transient induction of uncoupling protein-2 (Ucp2) mRNA expression in several brain regions, which included the CA1 subfield of the hippocampus, the dorsal endopiriform nucleus and the piriform cortex in both strains. In all those regions, levels of Ucp2 mRNA expression, as determined by in situ hybridization, peaked at 24 h and returned to basal levels within 72 h post-injection. The increase in mRNA expression was mainly observed in neurons, with microglial cells displaying only scattered expression of the gene. The neuronal induction of Ucp2 in response to KA was stronger in 129T2SvEmsJ mice than in C57BL/6J, which suggests a role for Ucp2 in excitotoxic challenges and neuroprotection.