A rodent model of sleep disturbances in posttraumatic stress disorder: the role of context after fear conditioning.
BACKGROUND
A prominent sleep disturbance, likely including a disruption of rapid eye movement sleep (REMS) continuity, characterizes posttraumatic stress disorder (PTSD). We set out to develop a fear conditioning paradigm in rats that displays alterations in sleep architecture analogous to those in PTSD.


METHODS
Baseline polysomnographic recordings of rats were performed in a neutral context to which the rats had been habituated for several days. Rats were then shock- or mock-trained in a distinctly different context, and their sleep was studied the following day in that context. A separate group of rats was shock-trained and studied in the neutral context on the following 2 days.


RESULTS
Rats that slept in the neutral context exhibited a REMS-selective increase in sleep 24 hours after training and increases in REMS and non-REMS 48 hours after training. In contrast, rats that slept in the presence of situational reminders of the training context exhibited a REMS-selective decrease in sleep 24 hours later. Animals that were mock-trained showed no changes in sleep.


CONCLUSIONS
Shock training induced days-long changes in sleep architecture that were disrupted when the animal was exposed to situational reminders of the training context.
Pawlyk
Aaron C
AC
Laboratory for the Study of the Brain in Sleep, Department of Animal Biology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania, USA.
Jha
Sushil K
SK
Brennan
Francis X
FX
Morrison
Adrian R
AR
Ross
Richard J
RJ
D000704:Analysis of Variance; D000818:Animals; D003213:Conditioning, Psychological / Q000502:physiology*; D003463:Cues; D004192:Discrimination, Psychological / Q000502:physiology; D004195:Disease Models, Animal; D004569:Electroencephalography / Q000379:methods; D004597:Electroshock / Q000009:adverse effects; D005239:Fear; D008297:Male; D017286:Polysomnography / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D012893:Sleep Wake Disorders / Q000209:etiology / Q000503:physiopathology*; D012895:Sleep, REM / Q000502:physiology; D013313:Stress Disorders, Post-Traumatic / Q000150:complications / Q000503:physiopathology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology