- 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
- 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
- To superior cervical ganglia
- Mature by age 2 yrs.
- Lots of melatonin may inhibit sexual development of children
- At puberty, melatonin decreases
- Hypothalamus to spinal cord
- Discovery
- Aaron Lerner
- Yale dermatology professor
- Hoped pineal gland substance would help treat skin diseases
- Called it melatonin
- Aaron Lerner
- 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
- Undetectable during day
- Also called
- 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
- Alfred Loomis, 1937
- 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
- transition from alpha (awake)
- 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
- Brief high-voltage peaks
- 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
- Deep or slow-wave sleep
- 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
- Be asleep
- 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?
- May have:
- 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
- 10 hr flight within time zone okay
- 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
- Before the flight
- 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
- Gradually adjust start of sleep
- 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
- CPAP machine
- During sleep
- 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
- Symptoms
- Jet Lag
- Stages
- 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
- Ancient
- Sequence of
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