Sleep Science Overview

A procedure that records the electrical activity of the brain using electrodes placed on the scalp.

A state of very light sleep where a person can be easily awakened.

A type of brain wave that appears in Stage 2 sleep, characterized by bursts of 12-15 Hz activity.

A type of brain wave feature in Stage 2 sleep that is a high-amplitude, sharp wave with a central-parietal location.

A complex brain wave feature in Stage 2 sleep formed by the overlap of vertex sharp waves and sleep spindles.

A network of blood vessels at the base of the brain that supplies blood to the brain.

Specialized capillaries in the brain that restrict the passage of substances from the blood to the brain tissue.

The process by which the brain uses oxygen and glucose to produce energy.

Gaps or pores between endothelial cells in capillaries outside the brain, allowing for easier passage of substances.

Extensions from astrocytes (brain cells) that wrap around capillaries in the brain, contributing to the blood-brain barrier.

Brain waves with a frequency of 9-11 Hz, seen in the back (posterior) of the brain during wakefulness.

A neurotransmitter that plays a role in sleep, particularly inhibiting the preoptic neurons in the hypothalamus, promoting sleep.

A neurotransmitter that helps regulate wakefulness and arousal, acting on the posterior hypothalamic neurons to promote wakefulness.

The neurotransmitter responsible for the 'fight-or-flight' response, which plays a role in wakefulness and arousal.

A brain region that plays a significant role in regulating sleep and wakefulness, particularly through its connection to the hypothalamus.

A stage of sleep characterized by rapid eye movements (REMs), vivid dreams, and muscle paralysis.

A neurotransmitter that plays a role in arousal and wakefulness, particularly in the pontine reticular formation.

Brain waves with a frequency of 13-30 Hz and low amplitude. They are irregular and appear when you're focused and attentive or under the influence of certain drugs.

Brain waves with a frequency of 30-80 Hz. They are associated with high levels of alertness and attention.

Brain waves with a frequency of 4-7 Hz. They are often associated with sleep and drowsiness but can also indicate abnormal brain activity.

Brain waves with a frequency of 0.5-3 Hz. They are the slowest brain waves and are most prominent during deep sleep and can also indicate certain neurological conditions.

Stages of sleep that are characterized by slow brain waves, decreased muscle activity, and slow breathing. There are four stages of non-REM sleep, each progressively deeper than the last.

A period of deep sleep in NREM sleep characterized by slow, large brain waves.

Electrical signals in the brain that are associated with the start and maintenance of REM sleep.

The ability of the brain to block out external stimuli during sleep.

The process of getting progressively less deep sleep as the night goes on.

Changes in sleep patterns over time, with less deep sleep and more REM sleep in older age.

The amount of sleep needed varies from person to person.

A sleep disorder characterized by frequent waking, unusual movements, and vivid dreams.

The ability of an organ, like the brain, to keep its blood flow stable even when the pressure supplying blood to the organ changes.

The brain's ability to maintain a steady blood supply and flow, even when blood pressure changes.

Changes in arterial blood pressure (BP) that are within the normal range for the brain (between 60-150 mmHg) trigger cerebral autoregulation to maintain blood flow.

Changes in the brain's metabolic demands, like increased activity, also trigger cerebral autoregulation to maintain blood flow.

The mechanism of cerebral autoregulation involving the smooth muscles in blood vessels that respond directly to changes in blood pressure.

The mechanism of cerebral autoregulation involving neural signals from the brain that control the blood vessels.

The mechanism of cerebral autoregulation involving chemical & metabolic factors that affect blood flow, like CO2

The ability of the brain to adjust its blood flow based on its own needs, even if the pressure supplying blood is changing.