Az alvás fenomenológiája

Az alvás definiciója aktivitás-nyugalom nem = alvás-ébrenlét az alvás általános kritériumai mozgás hiánya emelkedett szenzoros küszöb könnyű visszafordíthatóság sztereotíp testtartás specifikus pihenőhely cirkadian szerveződés szabályozottság: depriváció - rebound csukott szem talán a legfontosabb a rebound  emlős (és madár) - poligráfiás kritériumok

Az emberi alvás szakaszai Berger 1929: az éberségi szint szoros  kapcsolatban áll az EEG hullámaival: δ, θ, α, β, később γ  Loomis 1937: 5 alvási-ébrenléti szakasz – É és 4 LA Aserinsky és Kleitman 1953: paradox alvás leírása, kapcsolat az álmodással Rechtschaffen-Kales kritériumok LA1: 2-7 Hz, lassú szemmozgások, <20 μV LA2: orsók, K-komplexumok, kis amplitúdójú lassú hullámok LA3: <2 Hz >75 μV hullámok 20-50%-ban LA4: <2 Hz >75 μV hullámok >50%-ban REM: kérgi aktiváció, izomtónus megszűnése, gyors szemmozgások, PGO tüskék  Az alvásfázisokat hipnogrammon ábrázolják  állati alvás fázisok – egyszerűbb rendszer

Patkány alvásfázisai

Poligráfiás alvásfázisok

REM alvás macskában

Élettani változók alvás alatt

REM fázis emberben

Alvás és életkor

Diurnális és policiklusos alvás

patkány, uretán narkózis – piramis sejt, extracelluláris elvezetés down-states up-states long down-state felületes közepes anaesthetized rat (urethane?), recording with glass microelectrode then filtered to show both slow waves and unit activity upper track is DC in the depth of the cortex – holes!!!! successive increase in anesthesia depth: light, deeper, deep superficial urethane anesthesia DC recording with glass microelectrode; signal filtered differently: upper row low frequency, lower row high frequency medium level anesthesia as EEG (upper row) is measured at the level of the pyramidal cells, positivity means inhibition (down-state), negativity means excitation (up-state) neuronal firing is locked to up-state, i.e negativity deep anesthesia same picture, but up-states are very rare mély patkány, uretán narkózis – piramis sejt, extracelluláris elvezetés Bindman,L, Lippold,O., The Neurophysiology of the cerebral cortex, Edward Arnold, London, 1981, Fig 7.21

szabadon mozgó patkány – MUA aktivitás a piramis rétegből DROWSY 1 mV .2 mV down-states up-states intracellular recording from Halifax sampling rate was probably 1 kHz, thus insufficient, therefore spikes are poorly depicted figure constructed through Origin, using the file: rat_transcortical_EEG freely moving rat, L means recording from the pyramidal cell layer, S means recording from the cortical surface positivity in L (down-state) is accompanied by inhibition of neuronal activity negativity in L (up-state) is not that obvious, but it is associated with neuronal firing these changes are less obvious in the surface recording (S), but are opposite to L – negativity corresponds to down-state, positivity corresponds to up-state there was much speculation about the source of the large deep-positive waves, associated with silence in pyramidal cells first it was supposed to be caused by IPSPs, but all interneurons were shown to be silent together with the pyramidal cells Buzsaky suggested that large AHPs in pyramidal cells contributed to this waves Metherate, stimulating the BF, suggested that the up-states were caused by ACh blockade of different K+-currents, which also means, that down-states were brought about low activity in cholinergic cells, even if he didn’t claim this explilcitly Steriade thinks that the up-states are caused by mutual excitation of pyramidal cells, and the down-states by disfacilitation when this mutual excitation goes down – it is supported by the increased membrane resistance during down-states szabadon mozgó patkány – MUA aktivitás a piramis rétegből Buzsáki et al., J.Neurosci 8 (1988): 4007-4026

patkány, uretán narkózis – piramis sejt, intracelluláris elvezetés down-states up-states accidental intracellular recording from a pyramidal cell of a urethane-anesthetized rat and the simultaneous EEG recording with transcortical electrodes from the other hemisphere Steriade’s recordings are, of course much-much better, but it is mine! during the up-states, the cell is firing intensively and there are higher frequency waves on the EEG during down-states, EEG is a thin line only and the intracellular recording is noisy and with ECG artefacts, but not much else intracellular recording from Halifax sampling rate was probably 1 kHz, thus insufficient, therefore spikes are poorly depicted figure constructed through Origin, using the file: rat_transcortical_EEG patkány, uretán narkózis – piramis sejt, intracelluláris elvezetés Détári,L., unpublished data

Lassú kérgi ritmus Unanesthetized, head-restrained cat, intracellular recording. Steriade, M., et al., J. Neurophysiol. 85 (2001): 1969-1985

up SWS when you separate periods of up-, and down-states, it turns out that pyramidal cells are more active during up-states in SWS, than in wakefulness it is not clear, what the cells are doing – according to Steriade, they are exciting each other, as the thalamus blocks incoming information, but this claim is based on cerebellar stimulation and VL recording (as far as I know) in contrast, Portas in a Science paper claims that acoustic stimuli reach the auditory cortex in SWS just as during wakefulness W down Steriade, M., et al., J. Neurophysiol. 85 (2001): 1969-1985

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Gerinctelenek alvása csótány alvása skorpió alvása

Berger - 1929 bár voltak korábi próbálkozások állatok feltárt agykérgén (Richard Caton, 1875, Liverpool, majom és nyúl, tőle függetlenül Adolf Beck, 1891, Krakow, majd Lvov, nyúl és kutya – leírták a ritmikus oszcillációkat, az ingerek hatását, és a ritmusok függését az állat állapotától), az első, aki emberi EEG-t regisztrált a hajas fejbőrről, és leírta annak kapcsolatát az éberségi szinttel, Hans Berger volt Jenaban. az első regisztrálás saját fián 1925-ben a Siemens igen modern berendezéseivel 1929 és 1938 között 23 cikk (már akkor is fontos volt a publikációs lista)

EEG mintázatok

Alvásfázisok

Alvási ciklus Panel a depicts, in detail, features of an early-night sleep cycle in which NREM reaches its greatest depth at stage III and IV (delta) sleep. Panel b illustrates these changes over the course of a night's sleep. whereas panel c depicts a late-night cycle in which NREM descends only to stage III. Nature Reviews Neuroscience