Citation

Matsuda S, Matsuzawa D, Ishii D, Tomizawa H, Shimizu E. Neurobiol. Learn. Mem. 2018; 150: 93-98.

Affiliation

Department of Cognitive Behavioral Physiology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba, Chiba 260-8670, Japan; Research Center for Child Mental Development, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba, Chiba 260-8670, Japan.

Copyright

(Copyright © 2018, Elsevier Publishing)

DOI

10.1016/j.nlm.2018.03.007

PMID

29535045

Abstract

Onset of fear-related disorders such as post-traumatic stress disorder is enhanced from adolescence until adulthood. However, the biological mechanisms underlying this vulnerability remain unclear. Therefore, we investigated contextual fear memory and extinction in 4-, 6-, 8-, 10-, and 15-week-old female mice. We also measured phosphorylation of ERK2 in the medial prefrontal cortex (mPFC) and the dorsal hippocampus in the mPFC following fear conditioning or extinction in 6- and 15-week-old mice. We found that 10- and 15-week-old mice showed stronger fear memory and more resistance to fear extinction than 6-week-old mice. Moreover, 15-week-old mice showed lower ERK2 phosphorylation levels following fear extinction in the mPFC than those 6 weeks old. Our results suggest that female mice acquire strong fear memory and resistance to fear extinction throughout adulthood, which may be related to alteration in ERK2 activation in the mPFC.

Copyright © 2018. Published by Elsevier Inc.

Language: en

Keywords

Age differences; Extracellular signal-regulated kinase (ERK); Fear extinction; Fear memory; Females