Human Regional Cerebral Blood Flow during Rapid-Eye-Movement Sleep

Abstract

Summary: Owing to the coupling between CBP and neu ronal activity, regional CBP is a reflection of neural ac tivity in different brain regions. In this study we measured regional CBP during polysomnographically well-defined rapid-eye-movement (REM) sleep by the use of single photon emission computerized tomography and the new tracer 99mTc-dl-hexamethylpropyleneamine. Eleven healthy volunteers aged between 22 and 27 years were studied. CBP was measured on separate nights during REM sleep and during EEG-verified wakefulness. On awakening from REM sleep, all subjects reported visual dreams. During REM sleep CBP increased by 4% (p < Sleep represents a reversible state of disengage ment from the external environment. Sleep is not a uniform state of genuine unconsciousness, but is composed of a cyclical sequence of stages defined on the basis of electrophysiological parameters (Aserinsky and Kleitman, 1953;Rechtschaffen and Kales, 1968). In the sleep-wake cycle, rapid eye-movement (REM) sleep represents a distinct mental condition in the sense that it is closely cor related to the experience of dreams (Dement and Kleitman, 1957;McCarley, 1983). The understand ing of the dream phenomenon is sparse; we can only speculate on its significance, and the functional state of the dreaming brain is largely unknown. CBF is coupled to cerebral neuronal activity Received July 5, 1990; revised October 9, 1990; accepted Oc tober 10, 1990.Address correspondence and reprint requests to Dr. P. L. Madsen at Department of Clinical Physiology, Bispebjerg Hos pital, 23, Bispebjerg Bakke, DK-2400 Copenhagen NV, Den mark.Abbreviations used: HMPAO, dl-hexamethylpropyleneamine; OM, orbitomeatal plane; rCBF, regional CBF; REM, rapid eye movement; ROI, region of interest; SPECT, single photon emis sion computerized tomography. 502 0.01) in the associative visual area, while it decreased by 9% (p < 0.01) in the inferior frontal cortex. The CBP increase in the associative visual area suggests that acti vation of cerebral structures processing complex visual material is correlated to visual dream experiences. On the other hand, the reduced involvement of the inferior fron tal cortex observed during REM sleep might explain the poor temporal organization and bizarreness often experi enced in dreams. Key Words: Cerebral blood flow Dreams-99mTc-dl-Hexamethylpropyleneamine-Rapid eye-movement sleep--Single photon emission computer ized tomography. (Sokoloff, 1981). This means that information on the functional landscape of the brain can be ob tained by measuring CBF in different brain regions. However, owing to the elusive nature of sleep, ma jor restrictions are imposed on the examination methodology and during REM sleep only measure ments of regional CBF (rCBF) with a low resolution have been obtained. To study CBF during sleep, the examination technique should allow sleep in a seg regated room without causing interference. Single photon emission computerized tomography (SPECT) and the new tracer 99 mTc-dl-hexamethyl propyleneamine ( 99 mTc-HMPAO) meet...

Morning-evening variation in human brain metabolism and memory circuits

“…Beginning with the first quantitative study of brain circulation and metabolism prior to sleep in humans (Mangold et al 1955), 1 there have been a total of six additional studies in humans that we know of (Boyle et al 1994;Braun et al 1997;Buchsbaum et al 1989;Madsen et al 1991aMadsen et al , 1991bThomas et al 2000), one in monkeys (Kennedy et al 1982), one in cats (Reivich et al 1968), and one in mice (Vyazovskiy et al 2008). …”

“…An important corollary of this hypothesis is that an increase in synaptic density should boost the metabolic cost of brain function, because the majority of that cost originates in the synapses (for a recent review see Raichle and Mintun 2006). Despite an extant literature on quantitative measures of brain circulation and metabolism in relation to sleep in humans (Andersson et al 1998;Boyle et al 1994;Braun et al 1997;Buchsbaum et al 1989;Madsen et al 1991aMadsen et al , 1991bMangold et al 1955;Thomas et al 2003) and laboratory animals (Kennedy et al 1976;Reivich et al 1968;Vyazovskiy et al 2008), an adequate test of this cost-based hypothesis remains to be done.…”

Positron Emission Tomography with Deoxyglucose-F18 Imaging of Sleep

“…Most studies indicate that rates of global cerebral metabolism rate and cerebral blood flow (CBF) are similar during REM sleep and wakefulness (Buchsbaum et al 1989;Braun et al 1998;Franzini 1992;Kuboyama et al 1997;Lydic et al 1991;Madsen et al 1991;Madsen 1993;Maquet et al 1996). Nevertheless, the specific patterns of metabolic activity throughout the brain show distinctive regional differences between REM and waking conditions.…”

Functional neuroimaging of normal human sleep by positron emission tomography

“…In contrast to SWS, REM sleep is characterized by sustained neuronal activity (Jones 1990;Steriade et al 1990) and, correspondingly, by high cerebral energy requirements (Maquet et al 1990) and blood¯ow (Madsen et al 1991a;Madsen and Vorstrup 1991;Franzini 1992). In this working brain, some areas are more active than others; in contrast, other regions have lower than average CBF.…”

“…Detailed reviews cover these data and summarize their results (Madsen and Vorstrup 1991;Franzini 1992). Brie¯y, these data show that CBF in REMS is systematically higher than in SWS (Goas et al 1969;Lecas and Bloch 1969;Tachibana 1969;Seylaz et al 1975;Dufour and Court 1977;Milligan 1979;Mukhtar et al 1982;Richardson et al 1985Richardson et al , 1994Lenzi et al 1987;Meyer et al 1987;Parisi et al 1988;Abrams et al 1990;Zoccoli et al 1993Zoccoli et al , 1994Gerashchenko and Matsumura 1996), similar or slightly elevated as compared to W (Kanzow et al 1962;Reivich et al 1968;Townsend et al 1973;Shapiro and Rosendor 1975;Sakai et al 1980;Santiago et al 1984;Lenzi et al 1986Lenzi et al , 1987Parisi et al 1988;Cote and Haddad 1990;Madsen et al 1991a). Various results are observed during SWS: compared with W, decreases (Townsend et al 1973;Sakai et al 1980;Greisen et al 1985;Meyer et al 1987;Madsen et al 1991a, b;Gerashchenko and Matsumura 1996), increases (Reivich et al 1968;Goas et al 1969;Seylaz et al 1975;Shapiro and Rosendor 1975) or no change in...…”