Download PSYC550 Sleep and Sex

PSYC550
Biological Bases of Behavior
Sleep and Sex
A Physiological and
Behavioral Description of
Sleep
• alpha activity
– Smooth electrical activity of 8-12 Hz recorded from the brain;
generally associated with a state of relaxation.
• beta activity
– Irregular electrical activity of 13-30 Hz recorded from the brain;
generally associated with a state of arousal.
• theta activity
– EEG activity of 3.5-7.5 Hz that occurs intermittently during early
stages of slow-wave sleep and REM sleep.
• delta activity
– Regular synchronous electrical activity of less than 4 Hz recorded
from the brain; occurs during the deepest stages of slow-wave
sleep.
SWS vs REM
• NREM (SWS in stages 3 and 4)
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Alpha, delta, and theta activity
Light, even respiration
Lowered BP
Muscle control is present
Difficult to arouse (especially from stage 4)
• REM
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Asynchronized beta
Increased respiration and BP
REM
PGO waves
Spinal paralysis
Dreams
Sexual arousal
A Physiological and
Behavioral Description of
Sleep
• REM sleep
– A period of desynchronized EEG activity during sleep, at which
time dreaming, rapid eye movements, and muscular paralysis
occur; also called paradoxical sleep.
• non-REM sleep
– All stages of sleep except REM sleep.
• slow-wave sleep
– Non-REM sleep, characterized by synchronized EEG activity
during its deeper stages.
• basic rest-activity cycle
– A 90-minute cycle (in humans) of waxing and waning alertness,
controlled by a biological clock in the caudal brain stem; controls
cycles in REM sleep and slow-wave sleep.
Neurotransmitters involved
in Sleep
• Serotonin
– In raphe and pons
– Increased in SWS, decreased in REM
• Dopamine
– Decreased in REM
• Norepinephrine
– Decreased in REM
• Acetylcholine
– Greatly increased in REM
I get 8 hours of sleep each
night, without fail.
Strongly Agree
Agree
Disagree
Strongly Disagree
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Disorders of Sleep
• insomnia
– Discuss sleep hygiene
• drug dependency insomnia
– An insomnia caused by the side effects of ever-increasing doses of sleeping
medications.
• sleep apnea
– Cessation of breathing while sleeping.
• narcolepsy
– A sleep disorder characterized by periods of irresistible sleep, attacks of
cataplexy, sleep paralysis, and hypnagogic hallucinations.
• sleep attack
– A symptom of narcolepsy; an irresistible urge to sleep during the day, after
which the person awakens feeling refreshed.
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People with narcolepsy collapse
into sleep from total alertness
without warning.
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Agree
Disagree
Strongly Disagree
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http://www.youtube.com/watch?v=tOAvWbspeSQ&feature=related
Narcolepsy
• cataplexy
– A symptom of narcolepsy; complete paralysis that occurs during
waking.
• sleep paralysis
– A symptom of narcolepsy; paralysis occurring just before a
person falls asleep.
• hypnagogic hallucination
– A symptom of narcolepsy; vivid dreams that occur just before a
person falls asleep; accompanied by sleep paralysis.
• hypocretin
– A peptide, also known as orexin, produced by neurons whose cell
bodies are located in the hypothalamus; their destruction causes
narcolepsy.
Disorders of Sleep
• REM sleep behavior disorder
– A neurological disorder in which the person does not
become paralyzed during REM sleep and thus acts out
dreams.
•
•
•
•
•
Night terrors vs nightmares
Somnambulism
Somniloquy
Enuresis
Bruxism
Why do we sleep?
1. For restoration
2. To consolidate
memory
3. To remain safe from
predators
4. To learn to relax
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Why Do We Sleep?
• sleep-related eating disorder
– A disorder in which the person leaves his or her bed and seeks
out and eats food while sleepwalking, usually without a memory
for the episode the next day.
• fatal familial insomnia
– A fatal inherited disorder characterized by progressive insomnia.
• rebound phenomenon
– The increased frequency or intensity of a phenomenon after it
has been temporarily suppressed; for example, the increase in
REM sleep seen after a period of REM sleep deprivation.
• adaptive response to danger
Physiological Mechanisms
of Sleep and Waking
• locus coeruleus
– A dark-colored group of noradrenergic cell bodies located in the pons near
the rostral end of the floor of the fourth ventricle; involved in arousal and
vigilance.
• raphe nucleus
– A group of nuclei located in the reticular formation of the medulla, pons, and
midbrain, situated along the midline, contains serotonergic neurons.
• tuberomammillary nucleus (TMN)
– A nucleus in the ventral posterior hypothalamus, just rostral to the mammillary
bodies; contains histaminergic neurons involved in cortical activation and
behavioral arousal.
• ventrolateral proptic area (VLPA)
– A group of GABAergic neurons in the preoptic area whose activity suppresses
alertness and behavioral arousal and promotes sleep.
Physiological Mechanisms
of Sleep and Waking
• PGO wave
– Bursts of phasic electrical activity in the pons, followed
by activity in the lateral geniculate nucleus and visual
cortex, a characteristic of REM sleep.
• medial pontine reticular formation (MPRF)
– A region that contains neurons involved in the initiation
of REM sleep; activated by acetylcholinergic neurons of
the peribrachial area.
Physiological
Mechanisms of Sleep and
Waking
• magnocellular nucleus
– A nucleus in the medulla; involved in the muscular
paralysis that accompanies REM sleep.
Biological Clocks
• circadian rhythm
– A daily rhythmical change in behavior or physiological process.
• zeitgebers
– A stimulus (usually the light of dawn) that resets the biological
clock that is responsible for circadian rhythms.
• suprachiasmatic nucleus (SCN)
– A nucleus situated atop the optic chiasm. It contains a biological
clock that is responsible for organizing many of the body’s
circadian rhythms.
• melanopsin
– A photopigment present in ganglion cells in the retina whose
axons transmit information to the SCN, the thalamus, and the
olivary pretectal nucleus.
Biological Clocks
• pineal gland
– A gland attached to the dorsal tectum; produces
melatonin and plats a role in circadian and seasonal
rhythms.
• melatonin
– A hormone secreted during the night by the pineal
body; plays a role in circadian and seasonal rhythms.
Sexual Development
• sry
– The gene on the Y chromosome that instructs the
undifferentiated fetal gonads to become testes.
• organizational effect (of hormone)
– The permanent effect of a hormone on tissue differentiation and
development.
• activational effect (of hormone)
– The effect of a hormone that occurs in the fully developed
organism; may depend on the organism’s prior exposure to the
organizational effects of hormones.
Sexual Development
• defeminizing effect
– An effect of a hormone present early in development that reduces or prevents
the later development of anatomical or behavioral characteristics typical of
females.
• androgen
– A male sex steroid hormone; stimulates the development of the Wolffian
system. Testosterone is the principal mammalian androgen.
• masculinizing effect
– An effect of a hormone present early in development that promotes the later
development of anatomical or behavioral characteristics of males.
• testosterone
– The principal androgen found in males.
AIS
• androgen insensitivity
syndrome
– A condition caused by a
congenital lack of
functioning androgen
receptors; in a person with
XY sex chromosomes,
causes the development of a
female with testes but no
internal sex organs.
Sexual Development
• Turner’s syndrome
– The presence of only one sex chromosome (an X
chromosome); characterized by lack of ovaries but
otherwise normal female sex organs and genitalia.
Sexual Development
• follicule-stimulating hormone (FSH)
– The hormone of the anterior pituitary gland that causes development of an
ovarian follicle and the maturation of an ovum.
• luteinizing hormone (LH)
– A hormone of the anterior pituitary gland that causes ovulation and
development of the ovarian into a corpus luteum.
• estradiol
– The principal estrogen of many mammals, including humans.
• estrogen
– A class of sex hormones that cause maturation of the female genitalia, growth
of breast tissue, and development of other physical features characteristic of
females.
Copyright © Allyn & Bacon 2007
Hormonal Control of
Sexual Behavior
• oxytocin: The big “O”
– A hormone secreted by the posterior pituitary gland; causes
contraction of the smooth muscle of the milk ducts, the uterus,
and the male ejaculatory system; also serves as a neurotransmitter
in the brain.
• prolactin
– A hormone of the anterior pituitary gland, necessary for
production of milk; has an inhibitory effect on male sexual
behavior.
• lordosis
– A spinal reflex seen in many four-legged animals; arching of the
back in response to approach of a male or to touching the flanks,
which elevates the hindquarters.
Hormonal Control of
Sexual Behavior
• pheromone
– A chemical released by one animal that affects the behavior or
physiology of another animal; usually smelled or tasted.
• Lee-Boot effect
– The slowing and eventual cessation of estrous cycles in groups
of female animals that are housed together; caused by a
pheromone in the animals’ urine; first observed in mice.
• Whitten effect
– The synchronization of the menstrual or estrous cycles of a
group of females, which occurs in the presence of a pheromone
in a male’s urine.
Hormonal Control of
Sexual Behavior
• Vandenbergh effect
– The early onset of puberty seen in female animals that are housed with males;
caused by a pheromone in the male’s urine; first observed in mice.
• Bruce effect
– Termination of pregnancy caused by the odor of a pheromone in the urine of
a male other than the one that impregnated the female; first identified in mice.
• vomeronasal organ (VNO)
– A sensory organ that detects the presence of certain chemicals, especially
when a liquid is actively sniffed; mediates the effects of some pheromones.
• accessory olfactory bulb
– A neural structure located in the main olfactory bulb that receives information
from the vomeronasal organ.
Hormonal Control of
Sexual Behavior
• medial nucleus of the amygdala
– A nucleus that receives olfactory information from the
olfactory bulb and accessory olfactory bulb; involved in
the effects of odors and pheromones on reproductive
behavior.
• congenital adrenal hyperplasia (CAH)
– A condition characterized by hypersecretion of
androgens by the adrenal cortex; in females, causes
masculinization of the external genitalia.
Copyright © Allyn & Bacon 2007
Copyright © Allyn & Bacon 2007
Copyright © Allyn & Bacon 2007
Neural Control of Sexual
Behavior
• medial preoptic area (MPA)
– An area of cell bodies just rostral to the hypothalamus; plays an
essential role in male sexual behavior.
• sexually dimorphic nucleus
– A nucleus in the preoptic area that is much larger in males than in
females; first observed in rats; plays a role in male sexual
behavior.
• periaqueductal gray matter (PAG)
– The region of the midbrain that surrounds the cerebral aqueduct;
plays an essential role in various species-typical behaviors,
including female sexual behaviors.
Neural Control of Sexual
Behavior
• ventromedial nucleus of the hypothalamus (MH)
– A large nucleus of the hypothalamus located near the
wall of the third ventricle; plays an essential role in
female sexual behaviors.
The neural structure most
involved in female reproductive
behavior is:
1. Gone after the
honeymoon
2. The Medial Preoptic
Area (MPA)
3. The Ventromedial
Hypothalamus
(VMH)
4. The Hippocampus
(HPC)
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During paradoxical sleep, you will
expect an increase in the
neurotransmitter:
Serotonin
25% 25% 25% 25%
Norepinephrine
Dopamine
Acetylcholine