| Nicotine withdrawal signs include heightened anxiety, depression, trouble concentrating, restlessness and insomnia. Although many of these signs have been thoroughly researched, sleep disturbances have not, especially in rodent models. In the current study, rats were implanted with osmotic minipumps distributing nicotine bitartrate each day for 7 days. Once withdrawal was induced, the animals received either a vehicle-control injection or an injection of the selective 5HT2A antagonist MDL 100907. According to polysomnography, rats which received the MDL 100907 experienced more NREM and REM sleep during nicotine withdrawal than vehicle-injected rats. In addition, the MDL 100907 group experienced an increase in lower frequency delta and theta rhythms and a decrease in higher frequency alpha and gamma rhythms compared to the control group while asleep. In the subsequent wake-dominated dark period, the MDL 100907 group spent less time engaged in rebound sleep than the control group. These results are consistent with MDL 100907 reducing sleep fragmentation and increasing sleep intensity during nicotine withdrawal. |
