Electroacupuncture treatment normalized sleep disturbance in morphine withdrawal rats

Abstract

Sleep disturbance is considered as an important symptom of acute and protracted opiate withdrawal. Current results suggest that sleep disturbance may be taken as a predictor of relapse. Appropriate sleep enhancement therapy will be in favor of the retention in treatment for opiate addicts. Our previous studies have shown that electroacupuncture (EA) is effective in suppressing morphine withdrawal syndrome. The aim of the present study is to investigate the effect of 2 and 100 Hz EA on the sleep disturbance during morphine withdrawal. Rats were made dependent on morphine by repeated morphine injections (escalating doses of 5-80 mg kg(-1), subcutaneously, twice a day) for 5 days. EA of 2 or 100 Hz was given twice a day for 3 days, starting at 48 h after the last morphine injection. Electroencephalogram and electromyogram were monitored at the end of the first and the last EA treatments, respectively. Results showed that non-rapid eye movement (NREM) sleep, REM sleep and total sleep time decreased dramatically, while the sleep latency prolonged significantly during acute morphine withdrawal. Both 2 and 100 Hz EA produced a significant increase in NREM sleep, REM sleep and total sleep time. It was suggested that EA could be a potential treatment for sleep disturbance during morphine withdrawal.

Figure 1

Typical samples of EEG and EMG classified as wake, NREM sleep and REM sleep.

Figure 2

Schematic diagram for experimental design.

Figure 3

Sleep latency, time spent in NREM, REM sleep and total sleep time during 6-h recording in baseline and acute withdrawal days. Empty and filled columns show the data in baseline day and acute withdrawal day (starting at 24 h after last morphine injection), respectively. *P < .05; **P < .01; ***P < .001 compared with baseline by paired t-test; n = 15.

Figure 4

Effect of single EA treatment on sleep latency (a), time spent in NREM (c), REM sleep (b) and total sleep time (d) during 6-h recording after morphine withdrawal. Empty columns show the data during acute morphine withdrawal before various treatments, and filled columns after the treatment (single session of 2 Hz, 100 Hz or without EA in control group). *P < .05 compared with the data before treatment; ^# P < .05, ^### P < .001 compared with data after treatment in control group. ^! P < .05 compared with the data after treatment in 2 Hz group. n = 5.

Figure 5

Effect of 3-day EA treatment on sleep latency (a), time spent in NREM (c), REM sleep (b) and total sleep time (d) during 6-h recording after morphine withdrawal. Empty columns show the data during acute morphine withdrawal before various treatments and filled columns after the treatment (3-day EA treatment of 2 Hz, 100 Hz or without EA in the control group). *P < .05 compared with the data before treatment; ^# P < .05, ^## P < .01, ^### P < .001 compared with data after treatment in control group. n = 5.