NEUR200 Sleep

A comprehensive vocabulary set covering the biological rhythms, brain structures, sleep stages, and disorders discussed in the lecture.

Circadian rhythms

24-hour biological cycles influential in the regulation of sleep and other physical responses.

Zeitgeber

A 'time giver' (such as light) that readjusts people’s biological clocks by affecting the activity of the hypothalamus.

Suprachiasmatic Nucleus (SCN)

A part of the hypothalamus influenced by light that controls the release of melatonin in the pineal gland.

Retinohypothalamic pathway

The direct pathway in mammals through which light reaches the SCN.

Melatonin

A substance released by the pineal gland that makes us sleepy.

Reticular formation

A brain structure with ascending fibers that influence physiological arousal.

Orexin

A substance produced in the hypothalamus necessary to stay awake; its lack or inhibition can cause rats or humans to fall asleep quickly.

Narcolepsy

A disorder involving irresistible onsets of sleep during normal waking periods, caused by a lack of hypothalamic cells that produce orexin.

Stage 1 sleep

A sleep stage lasting $5$ to $10$ minutes characterized by EEG theta waves.

K-complex

Sharp waves occurring in Stage 2 sleep that signify temporal inhibition of neuronal firing, often produced after a sudden environmental interruption like noise.

Sleep spindles

Brief bursts of inhibition ($500\,ms$) generated in the thalamus during Stage 2 sleep; their presence is associated with being refreshed for learning tasks.

Stages 3 and 4 sleep

Slow-wave sleep characterized by high amplitude, low-frequency delta waves and a reduction of sensory input.

REM sleep (Stage 5)

Rapid Eye Movement sleep characterized by high-frequency beta waves in some brain areas and the occurrence of most dreams.

Insomnia

Chronic problems in getting adequate sleep, often caused by anxiety, tension, or depression.

Sleep apnea

A disorder characterized by frequent, reflexive gasping for air (of a minute) that awakens the sleeper.

Night terrors

Abrupt awakenings from NREM sleep accompanied by intense autonomic arousal and feelings of panic.

REM behavior disorder

A condition where individuals move vigorously during REM periods and act out their dreams, often due to a GABA deficiency.

Sleep as a local phenomenon

A concept where substantial inhibition occurs in one brain area but not another, explaining states like sleepwalking or lucid dreaming.

Fatal Familial Insomnia (FFI)

An inherited rare disease where the conversion of protein PrP to PrPres leads to thalamus degeneration, absence of sleep spindles, and eventually death.

PrPres

The protein that accumulates in greater amounts than normal in the thalamus of patients with Fatal Familial Insomnia (FFI).

Memory consolidation

The process of strengthening new synapses and weakening old ones during sleep; sleep spindles increase in number after new learning to aid this process.

Histamine

A substance released by the hypothalamus involved in brain structures for arousal.

Locus coeruleus

A structure located in the pons involved in maintaining physiological arousal.

Night terrors

Abrupt awakenings from Non-REM (NREM) sleep. Feelings of panic.

Nightmares

Anxiety-arousing dreams leading to waking.

Sleepwalking

Motor cortex is active.

Lucid dreaming

Frontal monitorings areas are active.

Sleep paralysis

Awake but not able to move.

What can higher amounts of PrPres in the thalamus?

lead to thalamus degeneration

what stage of sleep is disturbed in FFI? and what components?

stage two: k-complexes and sleep spindles.

what is reduced in FFI?

deep sleep

what can happen when awake in FFI?

REM can happen

what are symptoms of FFI?

weight loss, hallucinations, epileptic seizures, coma, death

What is the relationship between memories and sleep?

Important memories are consolidated.

What is the relationship between EEGs of sleep and new learning?

They resemble one another

What is the relationship between new learning the quantity of sleep spindles?

Sleep spindles increase in number after new learning happens.

What synaptic process occurs after new learning?

Synaptic pruning: Synapses are strengthened and old synapses are removed.

What is the reactivation process?

It is associated with the consolidation of forming a memory.

How does memory become strong?

Sleep.