Tutorial 05 Flashcards
What does the thalamic-mediated Synchronisation mechanisms do?
They give rise to large-scale integration of information across cortical circuits
Which sleep stage is the alpha waves?
Awake
Which sleep stage are theta waves?
REM and Non REM1
Which sleep stage are delta waves?
Non REM 3 – deep sleep
Which sleep stage are spindles and K-complexes?
Non REM 2
Sleep is a state of consciousness characterised by …
… low awareness and alertness with a higher threshold for sensory perception
The sleep stage is a function of …
… neural integration, with seemingly special role played by the gap junctions
What can we characterize to figure out the different Stages of sleep and how many sleep stages are there?
We can identify brain wave features, which characterize the 4 stages of sleep
Where is a competing balance in the brain to initiate nREM and REM sleep?
There is a competing balance between the front and back of the brain to initiate nREM and REM sleep
Is CR self sustained or entrained?
Both, CR is self-sustained; continues without external time-giving cues
CR is also entrained: synchronized by external time-giving cues
What is the circadian rhythm coordinated by?
CR is coordinated by Suprachiasmic Nuclei (SCN), lesion studies demonstrate their importance for sleep-wake patterns
What are the primary circadian photoreceptors? And where do they project to?
Melanopsin-containing retinal ganglion cells and they project to the SCN via a direct and an indirect pathway
Where does the suprachiasmatic nuclei signal to?
SCN signals to pineal gland to inhibit melatonin production
What happens to the pineal gland by an absence of light exposure?
Absent of light exposure, inhibition is removed and pineal gland releases melatonin
-> melatonin feeds back to SCN: permits sleep drive
Circadian rhythm sleep disorder?
A chronic recurring pattern of sleep and wake disturbances due to a) a dysfunction of the internal circadian clock system
B) a misalignment between timing of internal CR and externally imposed sleep wake cycles
Examples of circadian rhythm sleep disorders
Delayed sleep phase disorder
Non 24-hour sleep wake disorder
Advanced phase sleep disorder
Irregular sleep-wake rhythm disorder
Jet lag (chronic)
ICD-11 definition of insomnia
○ Disorder is characterized by difficulty in falling asleep and/or remaining asleep
○ Subjectively causes difficulties with daytime functioning or well-being
○ Experience sleep problems at least three times a week for at least three months
○ Even if circumstances/opportunities for sleep are ideal
Insomnia Disorder (Primary Insomnia)
constitutes an exclusionary diagnosis of poor sleep, ruling out
psychiatric, medical, substance, and other sleep-related pathology
Nighttime symptoms of insomnia
Difficulty initiating sleep, frequent awakenings, early morning awakening, reduced
sleep efficiency
Cognitive impairments
Memory and Attention Deficits, Impaired Executive Function, Emotional
Dysregulation
Sleep and stress
● Literature presents a dynamic and complex
relationship between stress and sleep
● Exposure to stress and even to insomnia itself causes
changes in the regulation of stress and sleep
● As a result, the conditions under which the initial
episode of insomnia develops may differ from the
conditions that perpetuate its course or give rise to
recurrent episodes
Restless REM sleep
Sound REM sleep is the only state during which the brain has a “time-out” of noradrenaline (NA): the
locus coeruleus (LC) is silenced
● Restless REM sleep, however, indicates insufficient LC silencing
→ The resulting lack of a NA-free REM sleep period disrupts synaptic plasticity
Hyperarousal
● Hyperarousal resembles the state of acute
anxiety or other emotional distress
● Hyperarousal in insomnia involves
imbalances in neurotransmitters like
noradrenaline, GABA, and glutamate
Manifestations of hyperarousal
somatic, emotional,
cognitive, cortical
