European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 8 - Number 2
Eur J Anat, 8 (2): 85-93 (2004)

The neuroanatomy of sleep. Considerations on the role of the thalamus in sleep and a proposal for a caudorostral organization

Lugaresi E., Provini F., Montagna P.

Department of Neurological Sciences, University of Bologna, Bologna, Italy; Dipartimento di Scienze Neurologiche, Università di Bologna, Via Ugo Foscolo 7, 40123 Bologna, Italy

ABSTRACT This review synthetizes the most important historical contributions in sleep anatomy and the pioneer discoveries in sleep medicine in the light of our clinical observations in Fatal Familial Insomnia (FFI), a genetic prion disease. Together with Morvan's chorea and Delirium Tremens, FFI is characterized by inability to sleep with severe loss of sleep spindles and delta sleep, with preserved presleep behaviour and abnormal REM sleep, associated with motor and autonomic overactivation. We labelled this pattern as Agrypnia Excitata (AE). AE is due to dysfunction in thalamolimbic circuits, which emphasizes the key role of the thalamus in sleep physiology and indicates that the anatomo-functional substrate of stage 1 non-REM sleep differs from that generating slow-wave-sleep (SWS, spindle and delta activity). Accordingly, the sleep-wake cycle in man should be conceptualized as consisting of 5 different behavioural and electrophysiological distinct states: active wakefulness, quiet wakefulness, drowsiness (or stage 1 non-REM), SWS (which incorporates spindle and delta sleep) and REM sleep. An intricate neuronal network extending from the caudal brainstem to the forebrain controls these different wake and sleep behaviours with several, at least three distinct generators.

Keywords: agrypnia excitata, autonomic dysfunction, behavior, brain stem, chorea, delirium tremens, drowsiness, fatal familial insomnia, history of medicine, human, limbic cortex, medical research, morvan chorea, motor dysfunction, nerve cell network, neuroanatomy, REM sleep, review, sleep, sleep spindle, sleep stage, sleep waking cycle, slow wave sleep, thalamus, wakefulness

European Journal of anatomy
ISSN 2340-311X (Online)