Increased serotonin receptor availability in human sleep: Evidence from an [18F]MPPF PET study in narcolepsy
Section snippets
Subjects
One of the problems faced by functional neuroimaging studies of human sleep is the lack of predictability with which spontaneous sleep occurs. We chose to study patients with narcolepsy as a way of circumventing this problem. Fourteen subjects with a diagnosis of narcolepsy (12 females, 2 males; mean age ± standard deviation: 52 years ± 14; age range: 26–67 years) were studied. The clinical features of the subjects are described in Table 1. The following inclusion criteria were applied: age
Part 1: human study
Of the 14 subjects studied, 7 slept for greater than 75% of the study (‘Good sleepers’) and 7 slept for less than 75% of the scan time (‘Poor sleepers’).
Discussion
In this study, we have demonstrated an increase in [18F ]MPPF binding in sleep, indicating increased 5HT1A receptor availability in sleep compared to wakefulness. To our knowledge, this is the first time such changes have been demonstrated in the living human brain.
Acknowledgments
We thank the technicians in the Department of Neurology and the Centre for PET for making this work possible, and John Sachinidis and Graeme O'Keefe their for technical support during the study. We are grateful to NODSS and all volunteers for their participation. This work was supported by grants from the NHMRC, the French–Australian Science and Technology Program and the Brockoff foundation.
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2019, NeuroscienceCitation Excerpt :In this regard, it has been reported that endogenous serotonin levels are reduced in some brain areas after acute seizures (Ferraz et al., 2002; Picard et al., 2011), in SE induced by pilocarpine (Mazarati, 2004; Lin et al., 2013), and in the chronic phase of different animal models of epilepsy, such as chemical kindling with PTZ (Szyndler et al., 2002). In addition, a number of animal studies have indicated that 18F-MPPF binding is sensitive to endogenous serotonin release (Derry et al., 2006; Rbah et al., 2003; Zimmer et al., 2002). Thus, the reduced levels of endogenous serotonin observed in the different epilepsy animal models could also lead to the observed increase 18F-MPPF BPND in this and other studies in epileptogenesis animal models (Di Liberto et al., 2018; van Dijk et al., 2018).
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