Polysomnograms of most homeothermic species distinguish two states, rapid eye movement (REM) and non-REM (NREM) sleep. These alternate several times during the night for reasons and following rules that remain poorly understood. It is unknown whether each state has its own function and regulation or whether they represent two facets of the same process. The present study compared the mean REM/N...

One of the hallmarks of rapid eye movement (REM) sleep is muscle atonia. Here we report extended epochs of muscle atonia in non-REM sleep (MAN). Their extent and time course was studied in a protocol that included a baseline night, a daytime sleep episode with or without selective REM sleep deprivation, and a recovery night. The distribution of the latency to the first occurrence of MAN was bim...

The effects of both REM sleep deprivation and its recovery on pontine and hippocampus muscarinic M2 receptors were investigated in synaptosomes using [3H]-AF-DX 384 as a ligand. Animals were divided into three groups: REM sleep deprivation group (small platforms 6.5 cm of diameter); stress group (large platforms 14 cm of diameter) and cage control group. In a second experiment REM sleep-deprive...

Sleep markedly affects fundamental mechanisms of motor control. Sleep not only suppresses postural muscle tone (Brooks and Peever, 2008b; Burgess et al., 2008), but it also attenuates, and in some cases even abolishes motor reflexes (e.g., H-reflex) (Wills and Chase, 1979). Mechanisms of motor control are also differentially affected by prevailing behavioral state. For example, muscle tone and ...

Sleep in depression is characterized by the occurrence of episodes of rapid eye movement (REM) sleep at sleep onset. The empirical foundations of three hypotheses about the origin of this phenomenon are examined: (I) A circadian rhythm hypothesis stating that sleep onset REM episodes (SOREMs) are the result of an abnormal phase-position of the REM sleep production cycle. (2) A REM sleep-slow wa...

Clomipramine (CLI), a REM sleep suppressant, alleviates symptoms of depression in adults but produces depressive behaviors if applied neonatally. Both effects of CLI as applied to adults and to neonates have been interpreted as consequences of its involvement in REM sleep deprivation. However, the paradox of these conflicting effects remains to be understood. The current study attempts to find ...

STUDY OBJECTIVE Examine the effects of donepezil on sleep and rapid eye movement (REM) sleep electroencephalogram (EEG) in patients with Alzheimer disease, using polysomnography, and the correlation between REM sleep EEG parameters and cognitive scores. DESIGN Randomized, double-blind, placebo-controlled design. SETTINGS Two sleep research centers, University Hospital. PARTICIPANTS Thirty...

STUDY OBJECTIVE To study tonic inputs to medullary respiratory neurons during rapid eye movement (REM) sleep. DESIGN Single medullary-respiratory-neuron recordings during sleep with spontaneous breathing and during apnea caused by mechanical hyperventilation. SETTING Academic laboratory. SUBJECTS Three tracheostomized adult cats implanted for polysomnography and extracellular microelectro...

Placental and marsupial mammals exist in three states of consciousness: waking, non-REM sleep, and REM sleep. We now report that the echidna Tachyglossus aculeatus, a representative of the earliest branch of mammalian evolution (the monotremes), does not have the pattern of neuronal activity of either of the sleep states seen in nonmonotreme mammals. Echidna sleep was characterized by increased...