Circadian Rhythms and Sleep

This set of flashcards covers key vocabulary related to circadian rhythms, sleep, and memory processes discussed in the lecture.

Circadian Rhythms

Biological processes that display a rhythm of about 24 hours, affecting physiological and biochemical processes.

Zeitgeber

An external cue that can synchronize an animal's endogenous rhythm, such as light.

Endogenous clock

An internal biological clock that regulates circadian rhythms, located in the suprachiasmatic nucleus.

Entrainment

The process of synchronizing biological rhythms to external cues.

Free-running period

The natural rhythm of an organism without external cues, such as light.

Phase shift

A shift in activity produced by a Zeitgeber, altering the timing of an organism's biological clock.

SCN (Suprachiasmatic Nucleus)

A tiny pair of neuron clusters in the hypothalamus that regulate circadian rhythms.

Ultradian rhythms

Biological rhythms that are shorter than a day, with cycles of minutes to hours.

Infradian rhythms

Biological rhythms with periods longer than a day, such as the menstrual cycle.

Long-term potentiation (LTP)

A long-lasting increase in the strength of synaptic transmission, believed to be a mechanism of memory formation.

Declarative memory

Memory of facts and events that can be consciously recalled.

Nondeclarative memory

Memory that does not require conscious thought, including procedural skills.

Anterograde amnesia

An inability to form new memories after an event, often associated with brain damage.

Retrograde amnesia

An inability to retrieve memories that were formed before a specific event, often due to injury.

Monoamine hypothesis of depression

The theory that depression is linked to reduced levels of neurotransmitters such as serotonin and norepinephrine.

Orexin

A neuropeptide involved in regulating wakefulness, with deficiencies linked to narcolepsy.

Sleep spindles

Periodic bursts of brain activity observed in EEG recordings during sleep.

Hypofrontality hypothesis

The theory that schizophrenia is associated with decreased activity in the frontal lobes of the brain.

Dopamine hypothesis of schizophrenia

The theory that schizophrenia is related to overactivity of dopamine transmission in certain brain regions.