Forming Competing Fear Learning and Extinction Memories in Adolescence Makes Fear Difficult to Inhibit

Autor/inn/en	Baker, Kathryn D.; Richardson, Rick
Titel	Forming Competing Fear Learning and Extinction Memories in Adolescence Makes Fear Difficult to Inhibit
Quelle	In: Learning & Memory, 22 (2015) 11, S.537-543 (7 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	1072-0502
DOI	10.1101/lm.039487.114
Schlagwörter	Fear; Inhibition; Adolescents; Animals; Animal Behavior; Neurological Organization; Brain Hemisphere Functions; Age Differences; Adults; Learning Processes + Suchen Sie Ihr Suchwort? Furcht; Hemmung; Adolescent; Adolescence; Adoleszenz; Jugend; Jugendalter; Jugendlicher; Animal; Tier; Tiere; Tierverhalten; Age; Difference; Age difference; Altersunterschied; Learning process; Lernprozess
Abstract	Fear inhibition is markedly impaired in adolescent rodents and humans. The present experiments investigated whether this impairment is critically determined by the animal's age at the time of fear learning or their age at fear extinction. Male rats (n = 170) were tested for extinction retention after conditioning and extinction at different ages. We examined neural correlates of impaired extinction retention by detection of phosphorylated mitogen-activated protein kinase immunoreactivity (pMAPK-IR) in several brain regions. Unexpectedly, adolescent rats exhibited good extinction retention if fear was acquired before adolescence. Further, fear acquired in adolescence could be successfully extinguished in adulthood but not within adolescence. Adolescent rats did not show extinction-induced increases in pMAPK-IR in the medial prefrontal cortex or the basolateral amygdala, or a pattern of reduced caudal central amygdala pMAPK-IR, as was observed in juveniles. This dampened prefrontal and basolateral amygdala MAPK activation following extinction in adolescence occurred even when there was no impairment in extinction retention. In contrast, only adolescent animals that exhibited impaired extinction retention showed elevated pMAPK-IR in the posterior paraventricular thalamus. These data suggest that neither the animal's age at the time of fear acquisition or extinction determines whether impaired extinction retention is exhibited. Rather, it appears that forming competing fear conditioning and extinction memories in adolescence renders this a vulnerable developmental period in which fear is difficult to inhibit. Furthermore, even under conditions that promote good extinction, the neural correlates of extinction in adolescence are different than those recruited in animals of other ages. (As Provided).
Anmerkungen	Cold Spring Harbor Laboratory Press. 500 Sunnyside Boulevard, Woodbury, NY 11797-2924. Tel: 800-843-4388; Tel: 516-367-8800; Fax: 516-422-4097; e-mail: cshpres@cshl.edu; Web site: http://www.learnmem.org/
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01