JNK1 contributes to metabotropic glutamate receptor-dependent long-term depression and short-term synaptic plasticity in the mice area hippocampal CA1.

Several recent reports implicate an important role played by c-Jun N-terminal kinases (JNKs) in long-term potentiation (LTP). However, little is known about how the isoforms of JNKs participate in synaptic plasticity. Here we showed that short-term synaptic plasticity was impaired in the hippocampal area CA1 of JNK1-deficient (JNK1-/-) mice; these mice showed normal LTP in response to a strong tetanus and no alteration of N-methyl-D-aspartate receptor-dependent long-term depression (LTD) in the hippocampus. However, LTD induced either by group I metabotropic glutamate receptors (mGluRs) agonist dihydroxyphenylglycine or by paired-pulse low-frequency stimulation was absent in both the JNK1-/- slices and in JNK inhibitor anthrax [1, 9-cd] pyrazol-6(2H)-1 (SP600125)-pretreated slices. Induction of mGluR-dependent LTD resulted in an increase in phosphorylation of JNK1 substrates, including p-c-Jun and p-ATF2 in wild-type (WT) mice, and these increases failed to occur in the JNK1-/- or SP600125-pretreated mice. These results demonstrated that JNK1 played a crucial role in the short-term synaptic plasticity and mGluR-dependent LTD, whereas hippocampus LTP was not affected by JNK1 deficiency.