DAY 1: SLEEP PHYSIOLOGY I ANATOMY

Question 1

According to Alessandro Silvani’s conference, what are some physiological functions in the body affected by sleep?

Answer 1

Sleep affects multiple physiological functions in the body, including the eyes, respiratory system, heart rate, metabolism, skeletal musculature, blood pressure, and consciousness.

Question 2

How was sleep described in Alessandro Silvani’s conference?

Answer 2

Sleep was described as an active metabolic engagement, suggesting that it is not simply a passive state but rather a dynamic process that influences various bodily functions.

Question 3

What are the different stages of sleep mentioned in the conference?

Answer 3

The different stages of sleep mentioned are muscle atony (muscle relaxation), awakeness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep.

Question 4

What is the significance of the sublaterodorsal nucleus (SLD) in sleep control?

Answer 4

The sublaterodorsal nucleus (SLD) plays a critical role in regulating muscle activity during sleep. Dysregulation of glutamate metabolites in the SLD can occur in Parkinsonian patients, potentially impacting their sleep and muscle control.

Question 5

How does the diaphragm contribute to maintaining proper respiratory function during sleep?

Answer 5

The diaphragm decreases muscle activity throughout the different phases of sleep, helping to maintain proper respiratory function.

Question 6

What is the role of the velopharynx in the respiratory system?

Answer 6

The velopharynx is responsible for regulating airflow between the nasal and oral cavities. It closes off the nasal passage during speech and swallowing to prevent air and food from entering the nasal cavity.

Question 7

Where is the oropharynx located and what functions does it serve?

Answer 7

The oropharynx is located at the back of the mouth, extending from the soft palate to the epiglottis. It serves as a passage for both air and food, facilitating swallowing and maintaining an open airway for efficient respiration.

Question 8

What is the function of the hypopharynx?

Answer 8

The hypopharynx, also known as the laryngopharynx, acts as a common pathway for both the respiratory and digestive systems. It helps direct food into the esophagus during swallowing and guides air into the larynx for respiration.

Question 9

What role does the circadian rhythm play in blood pressure control?

Answer 9

The circadian rhythm is a key factor in blood pressure control. Disruptions in the natural alignment of the internal body clock with the external environment can have effects on blood pressure regulation.

Question 10

How does sleep influence blood pressure and heart rate through autoregulation of blood flow?

Answer 10

During sleep, blood viscosity increases, leading to adjustments in blood flow to maintain adequate perfusion. Sleep, through the autonomic nervous system (ANS), influences blood pressure and heart rate, resulting in a decrease in both parameters.

Question 11

What techniques were used to study neural networks involved in sleep regulation in Christelle Peyron’s research?

Answer 11

Techniques such as analyzing brain lesions, studying neuronal markers, anterograde and retrograde tracing, and calcium imaging were used to understand the neural networks involved in sleep regulation.

Question 12

Which neurons were highlighted as wake-promoting neurons in Christelle Peyron’s research?

Answer 12

The wake-promoting neurons mentioned were acetylcholine, histamine, dopamine, serotonin, and noradrenaline.

Question 13

What is the role of orexin/hypocretin neurons in sleep regulation?

Answer 13

The absence of orexin/hypocretin neurons, which are excitatory neuropeptides, is a characteristic feature of Narcolepsy 1, highlighting their importance in sleep regulation.

Question 14

How does the accumulation of adenosine relate to sleep pressure and homeostatic drive?

Answer 14

The concept of homeostatic drive and sleep pressure building involves the accumulation of adenosine. Neurons such as GABA/GAL, eVLPO/MNPO, and VLPO are involved in the homeostatic regulation of sleep and are sensitive to light.

Question 15

What is the role of glutamatergic neurons in the sub-laterodorsal nucleus (SLD) during REM sleep?

Answer 15

Glutamatergic neurons in the sub-laterodorsal nucleus (SLD), specifically those expressing vGLUT2, are responsible for muscle atonia, a key characteristic of REM sleep.

Question 16

Which brain regions were identified as sleep-generating structures and regulatory regions in Christelle Peyron’s research?

Answer 16

The sleep-generating structures mentioned were the sub-laterodorsal nucleus (SLD) and LdT/PPT. The regulatory regions included the hypothalamus, specifically the melanin-concentrating hormone (MCH) neurons, and DPG/LPG.

Question 17

What role does vLPAG play in sleep-wake transitions?

Answer 17

vLPAG, a glutamatergic neuron, acts as a gatekeeper that decreases both non-REM (NREM) sleep and REM sleep, highlighting its role in sleep-wake transitions.

Question 18

What are some neurological conditions that can be impacted by sleep disorders?

Answer 18

Sleep disorders can have consequences on various neurological conditions, including schizophrenia, Parkinson’s disease, ADHD, bipolar disorder, depression, stroke, and epilepsy.

Question 19

What are the different sleep states discussed in A. Adamantidis’s presentation?

Answer 19

The sleep states discussed are wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep.

Question 20

What are some oscillatory patterns identified in different sleep states?

Answer 20

The identified oscillatory patterns include slow waves (SWS), delta waves, theta waves (6-9Hz), spindles, PGO (ponto-geniculo-occipital) waves, ripples, and gamma waves.

Question 21

What is the role of thalamus-cortical modulation in NREM sleep?

Answer 21

Thalamus-cortical modulation plays a role in determining the intensity and depth of NREM sleep, particularly in controlling NREM sleep slow waves.

Question 22

How does stroke impact sleep and recovery?

Answer 22

Stroke can impact sleep and recovery. Biostability and slow waves surround the site of the stroke, indicating the brain’s response. NREM sleep is shown to promote stroke recovery, but studies reveal that both REM and NREM sleep stages are affected, and complete recovery may not be achieved even after 10 days.

Question 23

What techniques were used to study the impact of specific neuronal activation and deactivation on sleep and memory consolidation?

Answer 23

Neuronal activation was achieved using ChR2 (channelrhodopsin-2), while neuronal deactivation was achieved using ArchT (archaerhodopsin). These techniques were employed to study the impact on sleep and memory consolidation.

Question 24

How does stroke affect sleep after its occurrence?

Answer 24

After stroke, there is an increase in spindles during the NREM phase, suggesting reduced restorative sleep. The deactivation of ArchT neurons also affects the NREM phase and memory consolidation by deactivating the theta rhythm (6-9Hz) during REM sleep.

Question 25

What were some of the oscillatory patterns discussed in relation to sleep states?

Answer 25

Some of the discussed oscillatory patterns include slow waves (SWS), delta waves, theta waves (6-9Hz), spindles, PGO (ponto-geniculo-occipital) waves, ripples, and gamma waves.

Question 26

What is the role of the suprachiasmatic nucleus (SCN) in our circadian rhythm?

Answer 26

The suprachiasmatic nucleus (SCN) serves as our circadian clock or master clock, located in the hypothalamus. It receives input from the optic chiasm and retinohypothalamic tract, connecting it to light signals received by the retina.

Question 27

Why is light considered a potent Zeitgeber for entraining the circadian clock?

Answer 27

Light acts as a potent Zeitgeber, or time cue, for entraining the circadian clock because it influences the timing and synchronization of our circadian rhythms to the 24-hour day, primarily through its effects on the SCN.

Question 28

How does the intrinsic period length of human circadian rhythms compare to the 24-hour day?

Answer 28

The intrinsic period length of human circadian rhythms is slightly longer than 24 hours, averaging around 24.2-24.9 hours. This indicates that without external cues like light exposure, our circadian rhythms would drift out of sync with the 24-hour day.

Question 29

How can one shift to an earlier sleep phase (advance the circadian clock) according to the general guidelines presented?

Answer 29

To shift to an earlier sleep phase, one should expose themselves to bright natural light, especially in the early morning upon waking. This helps signal to the body that it is time to be awake. It is advised to avoid bright artificial light sources, electronic devices, and screens close to bedtime, as they can delay the release of melatonin and make it harder to fall asleep earlier.

Question 30

What are some genetic factors that can influence an individual’s chronotype?

Answer 30

Specific genes such as PER3 and CLOCK have been associated with individual differences in the timing of circadian rhythms. Genetic polymorphisms, such as single nucleotide polymorphisms (SNPs), can impact an individual’s chronotype and susceptibility to circadian rhythm-related disorders.

Question 30

What should be done to shift to a later sleep phase (delay the circadian clock) based on the general guidelines provided?

Answer 30

To shift to a later sleep phase, one should expose themselves to bright natural light, especially in the evening. Spending time outdoors or near bright light sources in the evening helps signal to the body that it is not yet time for sleep, thus delaying the release of melatonin. In the morning, minimizing exposure to bright light, particularly natural sunlight, by keeping curtains closed or wearing sunglasses outdoors helps suppress the signal for wakefulness and allows the body to shift toward a later sleep phase.

Question 31

What is the main function of the glymphatic system?

Answer 31

The main function of the glymphatic system is the clearance of waste products and metabolites from the brain, including beta-amyloid, a protein associated with Alzheimer’s disease. It plays a role in maintaining brain homeostasis and promoting brain health.

Question 32

How does the glymphatic system differ from the lymphatic system in terms of location and structure?

Answer 32

The glymphatic system is primarily located in the brain and consists of a network of channels formed by the space between brain cells (astrocytes). On the other hand, the lymphatic system is a widespread network of vessels, lymph nodes, and organs distributed throughout the body.

Question 33

What drives the movement of fluid in the glymphatic system, and how is it different from the movement of lymph fluid in the lymphatic system?

Answer 33

The movement of fluid in the glymphatic system is driven by the pulsation of blood vessels and the contraction of glial cells, facilitating the flow of cerebrospinal fluid (CSF) through the brain’s interstitial space. In contrast, the movement of lymph fluid in the lymphatic system is primarily facilitated by the contraction of smooth muscle cells surrounding the lymphatic vessels.

Question 34

What are the neurotoxic effects of aggregated amyloid-beta (Aβ) peptides in Alzheimer’s disease?

Answer 34

Aggregated amyloid-beta (Aβ) peptides can induce toxicity in neurons, leading to their dysfunction and eventual death. This neurotoxicity is thought to contribute to the cognitive decline and neurodegeneration seen in Alzheimer’s disease.

Question 35

How does sleep quality impact the glymphatic system and amyloid-beta (Aβ) accumulation?

Answer 35

Poor sleep quality can increase interstitial permeability, potentially leading to increased Aβ accumulation. Adequate and restorative sleep is essential for proper glymphatic clearance and efficient waste removal from the brain.

Question 36

What is the role of the aquaporin-4 (AQP4) protein in the glymphatic pathway?

Answer 36

The aquaporin-4 (AQP4) protein, highly expressed on glial end feet lining blood vessels, is involved in the glymphatic pathway. It plays a crucial role in facilitating the flushing away of residues, including amyloid-beta (Aβ), from the brain.

Question 37

How did Francesca Siclari describe sleep?

Answer 37

The presentation described sleep as not merely a state of unconsciousness but involving internally generated experiences and subjective phenomena.

Question 38

What factors influence dream recall?

Answer 38

Factors influencing dream recall include age, gender, personality traits, motivation, and sleep structure, particularly nocturnal awakenings.

Question 39

When is dreaming most common according to the neurobiology of dreaming discussed in the presentation?

Answer 39

Dreaming is most common during non-rapid eye movement (NREM) sleep, as highlighted in the presentation.

Question 40

What were the two types of sleep discussed in infancy during the pediatric session on sleep?

Answer 40

In infancy, the two types of sleep discussed were active sleep and passive sleep.

Question 41

Around what age does slow wave activity, reflecting deep sleep, peak during childhood?

Answer 41

Slow wave activity, reflecting deep sleep, peaks around 10 years of age during childhood.

Question 42

What process occurs during childhood around the age of 10 years, coinciding with the peak of slow wave activity?

Answer 42

Around the age of 10 years in childhood, cortical maturation occurs, which coincides with the peak of slow wave activity and reflects significant brain development with increased synaptic density.

Question 43

What is the process of eliminating unnecessary neuronal connections to refine neural circuitry during adolescence?

Answer 43

During adolescence, the process of eliminating unnecessary neuronal connections to refine neural circuitry is called pruning.

Question 44

Why is adolescence often referred to as a “perfect storm” in terms of sleep challenges?

Answer 44

Adolescence is often referred to as a “perfect storm” because of the conflict arising from societal pressures and changes in circadian rhythm during this stage, which can affect sleep patterns and overall well-being.

Question 45

What percentage of mental disorders develop before the age of 14, as emphasized in the presentation?

Answer 45

Approximately 50% of mental disorders develop before the age of 14, as highlighted in the presentation.

Question 46

What is polysomnography (PSG) used for in sleep assessment and monitoring?

Answer 46

Polysomnography (PSG) is used to measure various physiological parameters during sleep, such as brain wave activity (EEG), eye movement (EOG), and muscle activity (EMG).

Question 47

What are the key components of polysomnography?

Answer 47

The key components of polysomnography include the electroencephalogram (EEG) for monitoring brain wave activity, electro-oculogram (EOG) for eye movement detection, and electromyogram (EMG) for measuring muscle activity.

Question 48

How is sleep divided into different phases or stages?

Answer 48

Sleep is divided into different phases or stages, including wakefulness (W), light sleep stage 1 (N1), light sleep stage 2 (N2), slow wave stage 3 (N3), non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep.

Question 49

What neurotransmitter levels are highest during NREM sleep, and what does it inhibit?

Answer 49

Noradrenaline (NA) levels are highest during NREM sleep, and it inhibits sleep spindles.

Question 50

Which physiological event indicates a regular response during sleep?

Answer 50

The occurrence of strong alpha waves in the electroencephalogram (EEG) during the event of eyes opening indicates a regular response.

Question 51

What is hypercapnia, and in what context was it mentioned during the presentation?

Answer 51

Hypercapnia refers to high levels of carbon dioxide (CO2) in the body. It was mentioned in the context of physiological changes during sleep.