Biological Psych Sleep Limbic System (con t) Pineal Gland Also called pineal body epiphysis cerebri epiphysis third eye Endocrine gland Produces melatonin Derivative of serotonin Affects modulation of wake/sleep Shape of pine cone Size of grain of rice Reddish-gray in color Calcifies as get older Brain sand Tumors are rare Composed of: Pinealocytes cell body with 4 6 processes produce & secrete melatonin Interstitial cells between pinealocytes Conjecture Near death experience? Psychedelic experiences? Antidepressants (Prozac)? Cocaine? Transducer Like adrenal medulla Converts sympathetic nervous system to hormones How it works Hypothalamus to spinal cord To superior cervical ganglia To pineal gland
Mature by age 2 yrs. Lots of melatonin may inhibit sexual development of children At puberty, melatonin decreases Discovery Aaron Lerner Yale dermatology professor Hoped pineal gland substance would help treat skin diseases Called it melatonin Melatonin Tryptophan Serotonin--Melatonin Production $ by darkness Inhibited by light Photosensitive cells in retina Detect amount of light Signal SCN Set 24-hr cycle Duction $ by darkness Movement of 1 eye Retina SCN signal PVN Paraventricular nuclei to Signal spinal cord then to Superior cervical ganglia and then to Pineal gland Blood levels of melatonin Undetectable during day rise sharply when dark Longer the night, more melatonin Some effect on sleep Not major regulator If you take melatonin Mild help to elderly insomniacs Shift workers Not as good as phototherapy Jet lag Taken close to target bedtime Best effect when crossing many time zones
Sleep Stages Awake REM Stage 1 Stage 2 Stage 3 Mammals and birds REM NREM N1 N2 N3 (delta) = slow wave sleep; deep sleep Historically: Alfred Loomis, 1937 EEG; five levels (A to E) Dement & Kleitman, 1953 REM sleep plus 4 NREM Now, 3 stages plus REM combined stages 3 and 4 Stages based on EEG, eye movements, respiratory, cardiac, and movement events Cycles N1 N2 N3 N2 REM proportion of REM sleep increases until just before natural awakening In humans (adults) Sleep cycle from 90 to 110 min. 60 minutes for newborns NREM Relatively little dreaming in NREM Stage N1 transition from alpha (awake) 8-13 HZ alpha waves To delta waves 4 7 Hz delta waves Somnolence or drowsy sleep Twitches and jerks Hallucinations Lower awareness of external environment
Stage N2 Less movement, no awareness About 50% of sleep time K-complexes Brief high-voltage peaks roughly every minute often followed by bursts of sleep spindles Suppress cortical arousal Expect to danger signals Aides memory consolidation Sleep Spindles Also called "sigma bands" or "sigma waves Last half second Sudden bursts Stage N3 Deep or slow-wave sleep minimum of 20% delta waves Night terrors Bed wetting Sleepwalking REM Rapid eye movement sleep 20 25% of total sleep time rapid eye movements rapid low-voltage EEG Memorable dreaming Paralysis Sleep timing Controlled by circadian clock Timekeeping, temperature-fluctuating, enzyme-controlling device Adenosine (neurotransmitter) Inhibits wakefulness Increases over the day Sleepiness Causes release of melatonin Gradual decrease in body temp Sleep duration affected by the DEC2 gene mutation of this gene; sleep two hours less than normal people
Optimal amount & timing Be asleep 6 hrs before lowest body temp Max level of melatonin Min core body temperature Adequate = not sleepy in daytime Varies with individual Varies with age Child to adult Hours by age Child need more sleep per day Newborn = up to 18 hrs 9 hours a day in REM sleep 1-3 yr olds = 12-15 School age = 10 to 11 hrs Adolescents = 9-10 hrs Adults = 7-8 More if pregnant Not less is elderly Sleep debt Not getting enough sleep Impacts frontal lobes Findings are mixed Lack of sleep Sign of cardiovascular disease? Too much sleep Sign of depression? Sleep Problems May have: Depression, alcoholism, bipolar 90% of depressed have sleep disorders? Sleep Deprivation Cognitive impairment Memory loss Moral judgment ADHD symptoms
Motor impairment Decreased reaction time Less accurate Tremors Aches Symptoms Irritable Yawning Hallucinations Impacts Immune system impairment Heart rate is more variable Risk diabetes & heart attack Decreased temp Sleep Disorders Jet Lag Called desynchronosis Alterations to circadian rhythms Sleep disorder May last several days Figure 1 day per time zone Out of synch w destination time contrary to accustomed rhythms times for eating, sleeping, hormone regulation and body temperature How long to adjust Varies greatly Cross 1-2 time zones no prob. Not linked to length of flight 10 hr flight within time zone okay Europe to southern Africa trans-meridian distance (west east) 5 hr flight from LA to NY International Date Line maximum possible disruption is 12 hours plus or minus Symptoms vary Headaches, irritability Fatigue, mild depression Sleep problems Digestive problems (constipation-diarrhea)
To minimize effects Before the flight Ask doctor about meds Partially adapt get up an hour earlier light box During flight Travel in smaller segments Overnight midway Set time to destination Sleep-wake After flight Sunlight Eat on schedule Travel west to east is hardest Most people have circadian period a little over 24 hours Easier to stay up later Harder to get up earlier London to LA: 8 hr difference Stay up all night, go bed at 6am LA to London: 8 hr difference Stay up all night, go bed at 2pm Red-eye flight West to east body gets less rest to begin day How fix Gradually adjust start of sleep Adjust over several days Avoid afternoon naps Eat on schedule, avoid carbs Melatonin? Hard to make timing precise Need max level 6 hours into sleep Light hits eyes, secretion stops Impacts circadian Light therapy One day per time zone adjust Start with light, avoid other times Possible but untested Fasting? lack of food overrides light-controlled circadian body clock? no food at all for 16 hours eat nothing on plane; don t eat until destination s breakfast time
Sleep apnea During sleep Abnormal pauses in breathing (apnea) Abnormal low breathing (hypopnea) Each apnea can last Seconds to minutes 5-30 per hour Sleep Study = polysomnogram Most common in men 2+ times for often Can affect children too excessive daytime sleepiness slower reaction time daytime fatigue vision problems Treatment CPAP machine Continuous Positive Airway Pressure pumps air into throat Turbinate surgery Grind down turbinates in nose Oral Appliance Therapy (OAT) Dental appliance; custom-made mouthpiece to shift lower jaw Narcolepsy Symptoms Excessive sleepiness Fall asleep at inappropriate times Work Driving Cataplexy Sudden muscular weakness when emotional Drop head, weak knees, collapse Slurred speech but normal hearing Often confused with insomnia REM within 5 minutes An hour before normal Possible genetic cause Treat with amphetamines Provigil or Nuvigil
Dreams Sequence of Images, sensation, emotions Occur involuntary Most common in REM sleep Most vivid in REM Purpose = unknown Duration of second to 20 min. Get longer as night progresses More REM as night progresses 5-minute dream is about 5-minutes of story Don t compress a day into 5 min. Remember if awakened in REM 3-5 dreams per night About 2 hrs per night Feel out of your control Except lucid self-aware dreams Can provide creative thoughts, problem solutions or inspiration REM has no release of: Norepinephrine, serotonin & histamine All mammals experience REM dolphins experience minimum humans are in the middle opossum and the armadillo most Theories Ancient Fates and gods talking to you Unconscious Mind Sigmund Freud Unconscious wishes Threat-simulation theory Antti Revonsuo Prepare you for real life Activation Theory Hobson & McCarley Random neuron firings