Knockout of c-Jun N-terminal kinases 1, 2 or 3 isoforms induces behavioural changes.

c-Jun N-terminal kinases (JNKs) are central and ubiquitous mediators of cellular signaling for both physiogical-regenerative and pathological-apoptotic processes. Their impact on degeneration or inflammation is well documented, but so far little is known about their roles in higher brain functions. The more, the contribution of individual JNK isoforms remains obscure so far. Here we have tested the behaviour of JNK1, JNK2 and JNK3 knockout (ko) mice in elevated plus maze (EPM), open field (OF), novel object recognition memory (NORM) test and Morris water maze (MWM). Compared with wild type C57BL/6N mice JNK ko mice revealed significant differences. Taken together the data on anxiety, exploration and learning indicate that JNK1 ko mice displayed a stronger explorative behaviour and that knockout of JNK2 or JNK3 showed a tendency of behaviour opposite to that of JNK1 ko mice. This pattern reminds of the impact of individual JNK ko on neurodegeneration. This is the first comparative study on the impact of individual JNK ko on behavioural parameters.