Impairments in Fear Conditioning in Mice Lacking the nNOS Gene

Autor/inn/en	Kelley, Jonathan B.; Balda, Mara A.; Anderson, Karen L.; Itzhak, Yossef
Titel	Impairments in Fear Conditioning in Mice Lacking the nNOS Gene
Quelle	In: Learning & Memory, 16 (2009) 6, S.371-378 (8 Seiten) PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	1072-0502
DOI	10.1101/lm.1329209
Schlagwörter	Animals; Cues; Scientific Research; Conditioning; Long Term Memory; Fear; Infants; Genetics; Neurological Organization; Context Effect; Auditory Stimuli; Brain; Brain Hemisphere Functions; Learning Processes; Metabolism + Suchen Sie Ihr Suchwort? Animal; Tier; Tiere; Stichwort; Langzeitgedächtnis; Furcht; Infant; Toddler; Toddlers; Kleinkind; Humangenetik; Auditive Stimulation; Gehirn; Learning process; Lernprozess; Stoffwechsel
Abstract	The fear conditioning paradigm is used to investigate the roles of various genes, neurotransmitters, and substrates in the formation of fear learning related to contextual and auditory cues. In the brain, nitric oxide (NO) produced by neuronal nitric oxide synthase (nNOS) functions as a retrograde neuronal messenger that facilitates synaptic plasticity, including the late phase of long-term potentiation (LTP) and formation of long-term memory (LTM). Evidence has implicated NO signaling in synaptic plasticity and LTM formation following fear conditioning, yet little is known about the role of the nNOS gene in fear learning. Using knockout (KO) mice with targeted mutation of the nNOS gene and their wild-type (WT) counterparts, the role of NO signaling in fear conditioning was investigated. Plasma levels of the stress hormone corticosterone were measured to determine the relationship between physiological and behavioral response to fear conditioning. Contextual fear learning was severely impaired in male and female nNOS KO mice compared with WT counterparts; cued fear learning was slightly impaired in nNOS KO mice. Sex-dependent differences in both contextual and cued fear learning were not observed in either genotype. Deficits in contextual fear learning in nNOS KO mice were partially overcome by multiple trainings. A relationship between increase in plasma corticosterone levels following footshock administration and the magnitude of contextual, but not cued freezing was also observed. Results suggest that the nNOS gene contributes more to optimal contextual fear learning than to cued fear learning, and therefore, inhibition of the nNOS enzyme may ameliorate context-dependent fear response. (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	2017/4/10