MAPK8 and isolated hemihyperplasia: IH effectively activated the NF-κB/JNK pathway and its downstream signaling molecules, confirming the role of the NF-κB-mediated JNK pathway in hippocampal injury and cognitive dysfunction in IH model rats.522 p38 MAPK is also a member of the MAPK family, and its activation has adverse effects on learning and memory.