Hanipsych, biology of dream

Biology of Sleep and Dream

Prof. Hani Hamed Dessoki, M.D.Psychiatry

Prof. Psychiatry

Chairman of Psychiatry Department

Beni Suef University

Supervisor of Psychiatry Department

El-Fayoum University

APA member

SLEEP & DREAMS

SLEEPSLEEP

Imagine...if on the average, people sleep 8 hours a day, they are sleeping away 1/3 of their life.

How much is that?

Perspectives on dreaming

Sigmund Freud, The Interpretation of Dreams (1900)

Struck by how often clients described them

“The royal road to the unconscious.”

©John Wiley & Sons, Inc. 2007 Huffman: Psychology in Action (8e)

Psychology in Action (8e)

by Karen Huffman

PowerPoint Lecture Notes Presentation

Chapter 5: States of ConsciousnessKaren Huffman, Palomar College


Understanding Consciousness

Consciousness (an organism’s awareness of its own self and surroundings)


Understanding Consciousness

Alternate States of Consciousness (ASCs): mental states, other than ordinary waking consciousness, found during sleep, dreaming, psychoactive drug use, hypnosis, etc.


Sleep and Dreams: Circadian Rhythms

Circadian Rhythms (biological changes occurring on a 24-hour cycle)

– Our energy level, mood, learning, and alertness all vary throughout the day.

– Sections of the hypothalamus called the suprachiasmatic nucleus (SCN) and the pineal gland regulate these changes.


Sleep and Dreams: Circadian Rhythms (Continued)

Disrupted circadian rhythms, through shift work, jet lag, and sleep deprivation may cause mood alterations, reduced concentration and motivation, increased irritability, lapses in attention, and reduced motor skills.


Sleep and Dreams

What happens to humans and other animals while we sleep and dream?


Sleep and Dreams: Stages of Sleep

NREM (Non-Rapid-Eye-Movement) Sleep:Stage 1(lightest sleep)Stage 2 (deeper sleep)Stages 3 and 4 (deepest sleep)

REM (Rapid-Eye-Movement) Sleep:Light sleep--also called paradoxical sleep


Sleep and Dreams: Stages of Sleep (Continued)

NREM (non-REM) sleep

– Includes Stages 1 through 4

– Lower-frequency brain waves, decreased pulse and breathing,and occasional, simple dreams

– Serves a biological need (NREM needs met before REM needs)


Sleep and Dreams: Stages of Sleep (Continued)

REM (Rapid-Eye-Movement) sleep

– Also called paradoxical sleep

– High-frequency brain waves, increased pulse and breathing, paralysis of the large muscles, and dreaming

– Serves a biological need and may help with learning and consolidating new memories


Sleep and Dreams: Why Do We Sleep?

Repair/restoration theory: sleep helps us recuperate from daily activities

Evolutionary/circadian theory: sleep evolved to conserve energy and as protection from predators

Cognitive theory: dreams are an important part of information processing of everyday experiences


Sleep and Dreams: Why Do We Dream?

Psychoanalytic theory: dreams are disguised symbols

(manifest versus latent content)

of repressed desires and anxieties

Biological theory: (activation-synthesis hypothesis) dreams are simple by-products of random stimulation of brain cells

Neural Regulation of Arousal

Electrical stimulation of the brain stem induces arousal

– Dorsal path: RF--> to medial thalamus --> cortex– Ventral path: RF --> to lateral hypothalamus, basal ganglia, and the

forebrain Neurotransmitters involved in arousal:

– NE neurons in rat locus coeruleus (LC) show high activity during wakefulness, low activity during sleep (zero during REM sleep)

LC neurons may play a role in vigilance– Activation of ACh neurons produces behavioral activation

ACh agonists increase arousal, ACh antagonists decrease arousal– 5-HT: stimulation of the raphe nuclei induces arousal whereas

5-HT antagonists reduce cortical arousal

Pharmacology of Arousal

Vigilance promoting

– Amphetamine enhances monoaminergic neurotransmission

– Caffeine blocks adenosine receptors

– Nicotine stimulates cholinergic receptors

Sleep promoting

– Alcohol, barbiturates, and benzodiazepines stimulate GABAA receptors

– Antihistamines block H1 receptors involved in cortical (and subcortical) arousal

Neural Control of SWS

The ventrolateral preoptic area (VLPA) is important for the control of sleep

– VLPA neurons promote sleeplesions of the preoptic area produce total

insomnia, leading to deathelectrical stimulation of the preoptic area

induces signs of drowsiness

– VLPA sends (inhibitory) GABA projections to locus coeruleus (NE), raphé nuclei (5-HT), and tuberomammillary nucleus (histamine)

Neural Control of REM Sleep

The pons is important for the control of REM sleep

– ACh neurons in the peribrachial pons modulate REM sleep Increased ACh increases REM sleep Peribrachial neurons fire at a high rate during REM sleep

Peribrachial lesions reduce REM sleep

– Pontine ACh neurons project to the thalamus (control of cortical arousal), to the basal forebrain (arousal and desynchrony), and to the tectum (rapid eye movements)

– Pontine cells project via magnocellular cells within medulla to the spinal cord: release glycine to inhibit alpha-motoneurons (induce REM motor paralysis or atonia)

NT Interactions: REM Sleep

There are specialized centres for particular varieties of sleep

SWS

REM

Suprachiasmatic Nucleus

The suprachiasmatic nucleus (SCN) contains a biological clock that governs some circadian rhythms– SCN receives input from

amacrine/ganglion cells in the retina, a pathway that may account for the ability of light to reset the biological clock (zeitgeber function)

the intergeniculate leaflet of the lateral geniculate thalamic nucleus

– This pathway may mediate the ability of other environmental stimuli to reset circadian rhythms (e.g. animals own activity)

– SCN lesions disrupt circadian rhythms

– SCN cells may not require direct neural connections to control circadian rhythms, but may do using chemical signals

SCN Clock Cells SCN cells exhibit circadian rhythms in activity

– SCN glucose metabolism (2-DG method) is higher during the day than during the night

– Each SCN cell appears to have its own clock (separate daily peaks in activity)

Yet SCN clock cells act in a synchronized fashion (a chemical rather than a neural effect)

Nature of clock cells

– Hypothesis was that clock cells produced a protein that upon reaching a critical level, inhibited its own production

Fruit fly: two genes per and tim control the production of two proteins: PER and TIM, eventually high levels of these proteins turn off the per and tim genes, resulting in declining levels of PER and TIM proteins, which in turn activates the two genes

Seasonal Rhythms SCN plays a role in governing seasonal rhythms

– Testosterone secretion in male hampsters shows an annual rhythm with increased secretion as length of day increases

This annual rhythm is abolished by SCN lesions; lesioned hampsters secrete testosterone all year long

Pineal gland interacts with the SCN to control seasonal rhythms

– The SCN projects to the PVN, which connects with the pineal gland which secretes melatonin

During long nights, the pineal gland secretes high amounts of melatonin

– Lesions of the SCN, of the PVN, or of the neural connection between the SCN and PVN disrupt seasonal rhythms controlled by day length

Activation-Synthesis Theory

Dreams are a product of activity from pons and/or brainstem)

Cerebral Cortex attempts to make sense of neuron firings by creatAing a story

Limbic system increase frontal lobe decrease

DREAMS HAVE NO MEANING!

Evidence

PET scans and other imaging techniques provide evidence for this.

Lucid Dreaming

Lucid dreaming occurs when dreamers realize that they are dreaming (lucid dreaming can occur with varying levels of awareness and dream control)

The dreamers are sometimes capable of changing their dream environment and controlling various aspects of their dream.

The dream environment is often much more realistic in a lucid dream, and the senses heightened

The realization is usually triggered by the dreamer noticing some impossible or unlikely occurrence in the dream

Lucid Dreaming

Two types of lucid dreaming: dream-initiated lucid dreaming and wake-initiated lucid dreaming

Dream-initiated lucid dreaming: Starts off as a normal dream until the dreamer realizes that they’re dreaming

Wake-initiated lucid dreaming: The dreamer goes from a normal waking state directly into a dream state with no apparent lapse in conscousness

Time passage appears to be the same during lucid dreaming as when awake

Most dreams are of Most dreams are of ordinary things. ordinary things.

BUTBUTLucid Dreams are so Lucid Dreams are so

vivid they SEEM REAL.vivid they SEEM REAL.

The Stuff of Which Dreams Are Made

These slides are visually enhanced versions of those created by Dr. Kevin Richardson, which are available at

http://bluehawk.monmouth.edu/~krichard/

Lucid Dreaming-is it real?

There are “How to” books on lucid dreaming, websites focused on teaching people the “art and science” of lucid dreaming, advertisements stating- "Now instead of wasting up to Eight Hours Every Single Day with normal sleep, by mastering the art of lucid dreaming I am now able to enjoy truly mind blowing experiences every night!” (www.lucid-dreamer.info)

Lucid dreaming is very appealing to people and many try to learn how to become lucid dreamers and “control” their dreams

Is this possible?

http://www.lucid-dreamer.info/

FACTS

Humans spend about 6 years dreaming Dreams are generated in the forebrain Most common emotion experienced during

dreaming is anxiety The U.S. ranks the highest amongst

industrialized nations for aggression in dreams with 50% of U.S. males reporting aggression in dreams, compared to 32% for Dutch men

Men generally have more aggressive feelings in their dreams than women, and children's dreams do not have very much aggression until they reach teen age

FACTS

This parallel much of the current research on gender and gender role comparisons in aggressive behavior

This supports the view that there is a continuity between our conscious and unconscious styles and personalities

In men's dreams 70 percent of the characters are other men, while a female's dreams contain an equal number of men and women

FACTS Sexual dreams show up about 10% of the time and

are more prevalent in young to mid-teens

Approximately 70% of women have recurring dreams and 65% of men

The most common themes are: situations relating to school, being chased, sexual experiences, falling, arriving too late, a person now alive being dead, flying, failing an examination, or a car accident

Twelve percent of people dream only in black and white

In general, more introverted, psychologically oriented people naturally remember their dreams and practical, concrete thinkers don’t

Sleep and Dreams“Sometimes

,a cigaris just acigar.”

Freud, on themeaning of dreams

These slides are visually enhanced versions of those created by Dr. Kevin Richardson, which are available at http://bluehawk.monmouth.edu/~krichard/

Children and Dreams

Almost the entire state of being before we're born is REM sleep

Researchers believe children have to reach a certain level of intellectual maturity, around the age of 8 or 9, before their dreams resemble adults‘

Research has shown that children dream about animals more often than adults and are more likely to report being victims than aggressors

Children and Dreams

Children are also more likely to have "fantastic" dreams, while adults' dreams tend to contain more elements of reality

The Basic Hypothesis• Dreaming is a basic cognitive activity.

• Mainly re-patterning and creative (at large)

• This is a physio-psychological function whether narrated as a declared dream or not.

• Its efficacy in the proper direction is assessed empirically through clinical monitors

• The phenomenon is basically related to the natural biorhythmic activity of human phenomenon.

Inner Eye

Dream Content

Dream Describtion

Dream and Creativity

What is it?A state of

apparently heightened

suggestibility

Post-Hypnotic Amnesia

Temporary memory

loss(Maybe)

You are getting sleepy…

But WHY Do We Dream?• Latent Content may actually be Unconscious Drives & Wishes

•

•Dreams may help sort & fix our days’ experiences in memory

•

• Dreams result from random neural activity originating in

brainstem

What if we couldn’t dream?These slides are visually enhanced versions of those created by Dr. Kevin Richardson, which are

available at http://bluehawk.monmouth.edu/~krichard/

These slides are visually enhanced versions of those created by Dr. Kevin Richardson, which are

available at http://bluehawk.monmouth.edu/~krichard/

Why Do We Daydream?

Temporary escape from reality;Temporary escape from reality;Help prepare us for future events; Help prepare us for future events; Substitute for impulsive behavior.Substitute for impulsive behavior.

Health & Medicine

Hanipsych, biology of dream