Possible involvement of hippocampal immediate-early genes in contextual fear memory deficit induced by cranial irradiation.

•Cranial irradiation impaired hippocampus-related memory.•Immediate–early genes (IEGs) are implicated in memory formation in the hippocampus.•Irradiation inhibited the induction of hippocampal IEGs via behavioral contextual fear memory.•The disturbance in the induction of IEGs may be related to radiation-induced memory deficits.