Biological Rhythms, Sleep, and Dreaming Flashcards
Zeitgebers
External cues (ex. Light and dark cycle), that entrails circadian rhythms
Free-running
Referring to a rhythm of behavior shown by an animal deprived of external cues about the time of day
Entrainment
The process of synchronizing a biological rhythm to an environmental stimulus
Suprachiasmic nucleus (SCN)
A small region of the hypothalamus above the optic chiasm that is the location of a circadian oscillator.
Pineal gland
Secretory gland in brine midline, secretes melatonin. In some animals, it is sensitive to light.
Retinohypothalamic pathway
From retinal ganglion cells splitting off from optic chiasm, synapse w/ SCN. Contain melanopsin
Melanopsin
Photopigment found in some retinal ganglion cells that project to SCN.
Infradian rhythms
Monthly rhythms (ex. Menstruation)
Circannual rhythms
Yearly rhythms (ex. Migration, hibernation, putting on weight in the winter, breeding seasons)
Ultradian rhythms
Cycle more than once a day (ex. Activity levels, eating, urination, drug effects differ at diff parts of day, sensitivity to pain)
Slow-wave sleep (SWS)
Sleep, divided into stages 1-3, that is defined by prescience of slow-wave EEG activity (synchronized)
REM sleep
Stage of sleep characterized by small-amplitude, fast-EEG waves (like awake) no postural tension, and rapid eye movements. Muscles are paralyzed, storyline dreams.
Desynchronized EEG
Also called beta activity. A pattern of EEG activity comprising a mix of many different high frequencies with low amplitude
Alpha rhythm
A brain potential of 8-12 Hz that occurs during relaxed wakefulness, increased freq from beta waves. Increased amplitude
Vertex spike
A sharp EEG pattern that is seen during stage 1 SWS sleep
Stage 1 sleep
The initial stage of SWS which is characterized by small-amplitude EEG waves of irregular freq, slow hr, and reduced muscle tension.
Stage 2 sleep
A stage of SWS that is defined by bursts of regular sleep spindles
Sleep spindle
A characteristic wave in EEG of a person in stage 2 sleep.
K complex
A sharp negative EEG potential that is seen in stage 2 sleep.
Stage 3 sleep
A stage of SWS that is defined by the spindles seen in stage 2 sleep, which is defined by prescience of delta waves (slow). Start to synchronize brain activity
Delta wave
The slowest type of EEG wave, characteristic of stage 3 SWS.
Nightmare
A long, frightening dream that awakens the sleeper from R.E.M.
Night terror
A sudden arousal from stage 3 sleep that is marked by intense fear and autonomic activation
Sleep cycle
A period of SWS followed by R.E.M. In Hunan about 90-110 min
PGO waves
Present during dreams. Pons- Geniculate- occipital.
Dream function
Consolidation of info during dreaming. What is important to remember in wakefulness
Sleep deprivation
Partial or total prevention of sleep. Can cause death
Sleep recovery
The process of sleeping more than is normal, after a period of sleep deprivation, as though in compensation.
Biological functions of sleep
Conserves energy, niche adaptation, rest and restoration (not so much for body but for brain), memory consolidation.
Isolated brain (encéphale isolé)
Cut between medulla and spinal cord. Brainstem isolated from spinal cord. Found brain generates sleep.
Isolated forebrain (cerveau isolé)
Cut hindbrain from upper parts of brain. Divides forebrain and brainstem. Constant SWS result. Upper brain makes R.E.M. Cycle.
Basal forebrain
Responsible for SWS generation. In frontal cortex and anterior hypothalamus. Releases GABA. Animal will not sleep if not activated
Reticular activation system (reticular formation)
Ascending - sends fibers to brain. Generates wakefulness. Projects to forebrain.
Pons
Generates R.E.M. (PGO waves). Inhibits motoneurons from firing. (GABA). Below locus coreleus which generates epinephrine.
Hypothalamus
Switchers between 3 states of wake/ SWS / R.E.M.
Sends to other systems.
If don’t have receptor–> narcolepsy
