Chapter 12 Neuroscience

REM

high-frequency brain activity in the hippocampus (resembling wakefulness), vivid dreaming, rapid eye movements, and skeletal muscle paralysis

Recuperation Theory

sleep is an active process used to repair cellular components, replete energy stores, and clean waste products accumulated in the brain and body during the day

Evolutionary Adaptation Theory

shaped by natural selection to conserve energy and reduce risk by keeping animals inactive during times when they are most vulnerable, such as darkness

Brain Plasticity Theory

Memories are encoded while awake, but actively stabilized, strengthened, and integrated into long-term memory during sleep

Circadian Rythms

24-hour biological clock that regulates sleep-wake cycles, hormone release, body temperature, and metabolism in humans and most organisms.

Ultradian Rythms

biological cycle that occurs more than once within a 24-hour period, specifically the alternating pattern of NREM (non-rapid eye movement) and REM (rapid eye movement) sleep

Infradian Rythms

biological cycles that last longer than 24 hours, often extending over weeks, months, or even a year (menstrual cycles)

Serotonin

Promotes wakefulness, generally regulates the transition between REM and NREM sleep, produced in the brain stem

Noradrenaline

Inhibits REM sleep, directly linked to waking state arousal and "fight or flight" alertness, produced in the locus coeruleus (pons)

Acetylcholine (ACH)

Adenosine

Accumulation of this neurochemical heavily correlates with sleep drive (need for sleep feeling). Caffeine acts as an agonist, delaying sensation of sleepiness

Dopamine

Acts as a major wake-promoting neurotransmitter, keeping the brain alert and inhibiting sleep (“tired but wired” with sleep deprivation)

Histamine

Stability agent for wakefulness neurotransmitter, anti-histamines block these receptors and induce sleep

Suprachiasmatic Nucleus

Located in the hypothalamus, and begins sending signals to the pineal gland when the sun begins going down (supporting evolutionary adaptation sleep theory)

Reticular Formation

Hypothalamus

Onset Insomnia

Diffculty initiating sleep process

Maintenance Insomnia

Difficulty staying asleep

Fatal Familial Insomnia

A rare genetic condition characterized by a total lack of sleep, leading to death if left untreated

Obstructive Sleep Apnea

"mechanical" failure where the airway collapses despite brain signals

Central Sleep Apnea

"brain-to-body" communication failure, where the brain fails to signal breathing

Orexin

Acts as a stabilizing switch, preventing abrupt, unintended transitions between waking and sleep. Low levels connected to narcolepsy

Caffeine

Antagonist to Adenosine, blocks receptors, inhibiting sleep

Awake stage

Beta Waves - Low amplitude, high frequency waves (BATD)

NREM1

Alpha Waves - Increased amplitude, decreased frequency waves (BATD)

NREM2

Theta Waves - More amp than alpha waves, K complexes and sleep spindles present (BATD)

NREM3

Delta Waves - Higher amplitude than theta waves, low frequency (BATD)