Sleep + wakefulness (BB) Flashcards
In which state of awareness is growing hormone mostly secreted?
Slow wave sleep with abundance of delta waves
What is the restorative function of the extracellular space of the brain during the sleep wakefulness cycle.
The restorative function of sleep may be a consequence of the enhanced removal of potentially neurotoxic waste products that accumulate in the awake central nervous system.
most frequent sleep disorder
insomnia
somnambulism meaning
sleepwalking
Which of the following types of drugs constitutes the first choice to treat insomnia at present?
Benzodiazepines
What does EEG measure, and what generates its signals?
EEG records scalp voltage from synchronized postsynaptic potentials in pyramidal neurons, mainly driven by thalamocortical circuits.
What does synchronized vs. desynchronized EEG indicate?
Synchronized: High amplitude, low frequency (deep sleep).
Desynchronized: Low amplitude, high frequency (wakefulness/REM).
How do SWS and REM differ?
SWS= Slow-wave sleep
REM= Rapid eye movement sleep
SWS (Stages 3-4): Delta waves, restorative, glymphatic clearance.
REM: Beta waves, vivid dreams, memory consolidation, muscle atonia.
What is the sleep cycle progression?
N1 → N2 → N3 (SWS) → REM. Each cycle lasts ~90 minutes and repeats 4-6 times per night.
Which brainstem nuclei regulate wakefulness?
Locus coeruleus (NE): Arousal, alertness.
Raphe nuclei (5-HT): Sensory input regulation.
Pedunculopontine nuclei (ACh): Cortical activation (wake/REM)
Which nucleus of the hypothalamus control circadian rhythm?
suprachiasmatic nucleus (SCN)= Circadian rhythm regulation via light input.
Which nucleus of the hypothalamus promotes sleep via GABA?
Ventrolateral Preoptic nucleus (VLPO)= Promotes sleep via GABA
Which nucleus of the hypothalamus stabilizes wakefulness?
Lateral hypothalamus (orexin): Stabilizes wakefulness
tuberomammillary nucleus (TMN) is a histaminergic nucleus located within the posterior third of the hypothalamus; what is its role?
tuberomammillary nucleus (TMN) largely consists of histaminergic neurons (i.e. histamine-releasing neurons). It is involved with the control of arousal, learning, memory, sleep and energy balance
Which chemicals regulate sleep/wake?
Sleepy substances: Adenosine, melatonin, leptin.
Waking substances: Orexin, histamine, ghrelin.
How does alcohol affect sleep?
Acute: Sedation (GABA), reduced REM/SWS.
Chronic: REM rebound, fragmented sleep, apnea risk
Major sleep disorders?
Insomnia: Hyperarousal, stress.
Narcolepsy: Orexin loss → REM intrusion.
REM Behavior Disorder: Loss of REM atonia.
Sleep Apnea: Airway collapse, hypoxia
What lesions cause sleep disorders?
Anterior hypothalamus: Insomnia.
Posterior hypothalamus: Hypersomnia.
suprachiasmatic nucleus (SCN): Circadian rhythm disruption.
What is the role of the glymphatic system in SWS?
Clears neurotoxic waste (e.g., beta-amyloid) via expanded CSF spaces during NREM
Why is REM sleep critical?
Facilitates memory consolidation, emotional regulation, and synaptic plasticity
