- Academic Editor
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Background: Training with inescapable shock (IS; uncontrollable
stressor) is followed by significant decreases in rapid eye movement sleep (REM).
However, controllability is important in the effects of stress. We examined the
effects of escapable shock (ES; controllable stressor) on sleep and whether the
central nucleus of the amygdala (CNA) plays a role in regulating these effects.
Methods: Six Wistar rats implanted with a cannula located in CNA
underwent two days of ES training (20 shock presentations; 0.5 mA; 5.0 s maximum
duration; 1.0 min interstimulus interval). Five days later, they were re-exposed
to the shock context. Results: Following shock training, REM was
significantly increased in both light and dark periods. Non-REM (NREM) and total
sleep (TS) duration were decreased during the light period. Similar effects on
REM and NREM were observed following re-exposure to the training context alone.
Microinjections of saline into CNA immediately following ES also produced similar
increases in REM, whereas microinjections of muscimol (MUS; GABA