Glucocorticoids are not responsible for paradoxical sleep deprivation-induced memory impairments

Glucocorticoids are not responsible for paradoxical sleep deprivation-induced memory impairments

Author Tiba, Paula Ayalko Autor UNIFESP Google Scholar
Menezes Oliveira, Maria Gabriela Autor UNIFESP Google Scholar
Rossi, Vanessa Contatto Autor UNIFESP Google Scholar
Tufik, Sergio Autor UNIFESP Google Scholar
Suchecki, Deborah Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Study Objectives: To evaluate whether paradoxical sleep deprivation-induced memory impairments are due to release of glucocorticoids, by means of corticosterone inhibition with metyrapone.Design: The design was a 2 (Groups [control, paradoxical sleep-deprived]) x 2 (Treatments [vehicle, metyrapone]) study, performed in 2 experiments: Acute treatment (single injection given immediately after 96 hours of sleep deprivation) and chronic treatment (8 injections, twice per day, throughout the sleep-deprivation period). Animals were either paradoxical sleep-deprived or remained in their home cages for 96 hours before training in contextual fear conditioning and received intraperitoneal injections of a corticosterone synthesis inhibitor, metyrapone. Memory performance was tested 24 hours after training.Subjects: Three-month old Wistar male rats.Measurements: Freezing behavior was considered as the conditioning index, and adrenocorticotropic hormone and corticosterone plasma levels were determined from trunk blood of animals sacrificed in different time points. Animals were weighed before and after the paradoxical sleep-deprivation period.Results: Acute metyrapone treatment impaired memory in control animals and did not prevent paradoxical sleep deprivation-induced memory impairment. Likewise, in the chronic treatment, paradoxical sleep-deprived animals did not differ from control rats in their corticosterone or adrenocorticotropic hormone response to training, but still did not learn as well, and did not show any stress responses to the testing. Chronic metyrapone was, however, effective in preventing the weight loss typically observed in paradoxical sleep-deprived animals.Conclusions: Our results suggest that glucocorticoids do not mediate memory impairments but might be responsible for the weight loss induced by paradoxical sleep deprivation.
Keywords paradoxical sleep deprivation
learning
memory
metyrapone
contextual fear conditioning
corticosterone
weight loss
rat
Language English
Date 2008-04-01
Published in Sleep. Westchester: Amer Acad Sleep Medicine, v. 31, n. 4, p. 505-515, 2008.
ISSN 0161-8105 (Sherpa/Romeo, impact factor)
Publisher Amer Acad Sleep Medicine
Extent 505-515
Origin https://doi.org/10.1093/sleep/31.4.505
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000254936400010
URI http://repositorio.unifesp.br/11600/45603

Show full item record




File

File Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

Search


Browse

Statistics

My Account