1. Physiology of sleep and dreaming The sleep cycle Dreaming Why do we sleep?

2. Sleep and consciousness Diurnal rhythms 1 degree in the early evening higher Adrenocortical H.in the morning higher

3. Sleep –wake cycle When Awake : able to perform all activities for individual and species survival When sleep : is not aware and not able to ….

4. Assesment of sleep states 1- behavioral analysis 1- EEG analysis EEG : represent the summated activity of millions of cortical neurons.IPSPs and EPSPs and passive spread of electrical activity is the basis of EEG

5. The sleep cycle Electronic recording: EEG, EOG, EMG EEG patterns divide sleep into four stages: –1:  waves, 8 - 12 Hz, low amplitude, moderate frequency, similar to drowsy wakefulness –2: slower frequency, higher amplitude, plus K complexes Sleep spindles –3:  waves appear, 1-2 Hz, large amplitude –4: Dominated by  waves

6. REM sleep phenomena Stage 1 EEG: Paradoxical sleep EOG (and corneal bulge) show frequent eye movements, as if scanning a visual field. EMG shows loss of muscle tonus due to downward inhibition of  motor neurons, although muscles moving hands and feet may twitch. Many brain structures function as if awake.

7. More REM phenomena SNS is partially activated: Increases blood pressure, respiration, and heart rate. Genital response Narrative dreaming –CBF is high to visual cortex, low to inferior frontal cortex (Madsen, 1991) –Eye movements match dream events –One EEG waveform is unique to REM and wakeful scanning

8. Dream research External stimuli may be incorporated into a dream. Dream events happen in real time. Sleep-walking and talking are non-REM.

9. Interpretation of dreams Manifest content is symbolic of latent desires (Freud) Activation-synthesis theory: cf. incorporation of external events into dreams. Lucid dreams: Have you had one?

10. Why do we sleep? Restoration, recuperation or repair –Waking life disrupts homeostasis Protection with the circadian cycle Circadian synthesis

11. Who sleeps? Mammals and birds –Opossums, sloths, bats: 19-20 hours daily –Cats, dogs, rodents: 12-15 hours daily –Ruminant herbivores: 2-3 hours daily Reptiles, amphibians, fish, and insects have cycles of inactivity Note that sleep time does not correlate with waking activity levels, but does relate to waking vulnerability.

12. SWS

13. تغييرات مراحل خواب با افزايش سن

14. Sleep during infancy Neonate can sleep 18 hours during a 24 hour period During the first year of life the sleep period may be reduced to 12 hours Infant may have up to 50% of REM SLEEP or more, while adults have 20% Sleep cycles are shorter than in the adult, 50-60 min Cycles can start with REM sleep. REM is controlled by a more primitive center, brainsteam.

15. Slow Wave Sleep REM/Paradoxical Sleep EEG Large AmplitudeLow Amplitude (cf waking) Slow Waves ~ 1 Hz(but theta rhythm in hippocampus) MUSCLESReduced toneTotal relaxation (e.g. in postural & neck muscles) SPINAL Some reductionStrong descending inhibition REFLEXESof motoneurons AROUSALto ‘significant’ stimuliRaised threshold (deep sleep) but often waking from REM PHASICMuscle twitchesSudden eye movements (REM) EVENTSSudden CNS discharges REPORTS‘dreams’ 0-50%‘dreams’ 80%-90% ON WAKING& ‘thinking’

16. Slow Wave Sleep REM/Paradoxical Sleep ……ctd…. REPORTS‘dreams’ 0-50%‘dreams’ 80%-90% ON WAKING& ‘thinking’ % of SLEEP60% - 85%~40% infants ~20% most of life ~15% old age WHENInitially and in cyclesNot initially (except narcoleptics) ~ 90 min cycle

17. بررسي امواج EEG و EMG در مراحل مختلف خواب

18. نحوه قرارگيري الكترودها روي سر جهت ثبت EEG

19. الگوي جريان الكتريكي جهت ايجاد پتانسيل پس سيناپسي تحريكي

20. نحوه تغيير پولاريته امواج EEG

21. توليد پتانسيل عمل و كانالهاي دريچه ار ولتاژي كلسيمي تالاموس

22. ارتباط سطح فعاليت مغز و فركانس متوسط امواج مغزي

23. Circadian rhythms Zeitgebers and the SCN Free-running rhythms and the 25-hour period Internal desynchronization: free-running body temperature cycle and sleep-wake cycle may desynchronize.

24. Resynchronization Jet lag and shift work Phase shift: Delay is better than advance –Morning melatonin phase-delays –Afternoon melatonin phase-advances –Evening melatonin is ineffective –Bright light exposure has the opposite effects Strengthen zeitgebers like light and activity early in the new waking period

25. Neural control of sleep Is sleep a passive process? –The cerveau isole’ of Bremer (1936) –The encephale isole’ and the RAS –Partial transections leaving the RAS intact Ventrolateral Preoptic Area (VPA) triggers sleepiness and slow-wave sleep Warming the basal forebrain induces slow- wave sleep VPA receives input from thermoreceptors

26. More neural control PGO waves in the EEG from implanted electrodes Executive in the dorsolateral pons, called the peribrachial area. Kainic acid lesions of peribrachial area reduce REM sleep Carbachol, an ACh agonist, in ventral pons (medial pontine reticular formation) triggers REM phenomena.

27. طرح كنترل خواب REM

28. مدل ساختاري و ديناميك فعاليت مغز در خواب REM

29. The Ascending Arousal System Von Economo, C. J. Nerv. Ment. Dis. 71, 249–259 (1930)

30. Nuclei of certain known chemical neuro-modulatory systems AcetylCholine: Tegmentum [PGO] Noradrenaline: Locus Coeruleus [Arousal] 5HT (serotonin): Raphe [Arousal, SWS] Arousal and Neuro-modulatory Systems Thalamus Diffuse projection from RETICULAR ACTIVATING SYSTEM (R.A.S.) -> arousal ‘Specific’ sensory signals to thalamus and cortex ‘Non-specific’ collaterals of sensory axons go to RETICULAR ACTIVATING SYSTEM (R.A.S.)

31. The Ascending Arousal System Moruzzi, G. & Magoun, H.W. Electroencephalogr. Clin. Neurol. 1, 455–473 (1949) Known neurotransmitters originating from well-defined cell groups: LC: Locus Coeruleus BF: Basal Forebrain LH: Lateral Hypothalamus TMN: Tuberomamillary Nuclei LDT/PPT: Pedunculopontine / Laterodorsal Tegmental Nuclei NB: Link to von Economo’s work

32. REM is mediated by brainstem, through a cholinergic system Non-REM is mediated by the locus coeruleus of the brainstem and the messenger is adrenaline There may be a homeostatic load through the day that makes the need for rest imperative There are light/darkness cues perceived in the suprachiasmatic nucleous (hypothalamus)