wk 10 BB Flashcards
SCN is located in the
hypothalamus
lesions in SCN do what to sleep
still sleep and exercise normal ammount, just at haphazard times
greater SCN neuronal and metabolic activity during
daylight
light passes directly from the retina to the SCN via the
Retinohypothalamic pathway
how does the SCN control sleep and waking through Direct neural connections
process of SCN to DMH
synapse pathways from SCN to the
- subparaventricular zone (SPZ)
-then to Dorsomedial nucleus of the Hypothalamus (DMH)
how does the SCN control sleep and waking through Direct neural connections
process of DMH to sleep-wake flip-flop
- DMH sends inhibitory signals to vlPOA (GABAnergic system here) which is inhibitory, thus keeping us awake
DMH sends excitatory signals to Oxinergic neurons ( excitatory, this promotes wakefulness) (as oxinergic neurons stimulate arousal system)
evidence that the SCN control sleep and waking through release of chemical signals
system involving at least 7 genes and their proteins and two interlocking feedback loops.
– Proteins build up, inhibit gene producing proteins. Proteins lessen, stop inhibiting, proteins produced.
a biological clock
Insomnia
difficulty getting to sleep, staying asleep, or having non-restorative sleep
– together with associated impairment of daytime functioning.
– Defined in relation to a person’s
particular need for sleep
Chronic insomnia effects
approximately __% of the population
while up to 1/3 report at least one
nocturnal symptom (Morin & Jarrin, 2013;
Singareddy et al., 2012).
9
insomnia
Age
– More common in ____ people
older
Causes for insomnia = Physiology
Heightened activity in the reticular activating system
- Medical conditions and medications
impact on insomnia
E.g. Heart and respiratory conditions, some
antidepressants, epilepsy medications
Insomnia Treatment
Typically treated with drugs but can
potentially also be treated with
mindfulness and CBT (Manber et al.,
2011; Ong et al., 2014)
Chronic sleep deprivation can lead
to serious health problems e.g.
E.g. obesity, diabetes and
cardiovascular disease (Orzel-Gryglewska,
2010)
Sleep Apnea
Form of insomnia – the inability to
sleep and breathe at the same time
* Build of carbon dioxide
* Carbon dioxide in the blood
stimulates chemoreceptors
* Disrupts sleep affecting daytime
functioning
Narcolepsy
Symptoms
Sleep attack = overwhelming urge to sleep
Cataplexy = muscular paralysis of REM sleep while awake
Varying degrees of muscle weakness
➢ Can become completely paralyzed while conscious
➢ Generally occurs when the person feels strong
emotions or by sudden physical effort.
Sleep paralysis =
* REM muscular paralysis just before the onset
of sleep or upon waking
Hypnagogic hallucinations =
* dreaming while awake and paralysed
* can very realistic and terrifying.
Causes of narcolepsy
Hereditary element
Environmental factors play, but are unknown
Orexinergic neurons are attacked by the
immune system, usually in adolescence
(Fontana et al., 2010)
treatments for narcolepsy
Ritalin - stimulant drugs.
REM sleep phenomenon treated with antidepressants
most common = modafanil and sodium oxybate
REM sleep behaviour disorder
no paralysis during REM
= acting out dreams
Neurodegenerative disorder with a genetic component
associated with Neurodegenerative disorders such as Parkinsons
REM sleep behaviour disorder treatment
clonazepam , a benzodiazepine tranquilliser
Sleepwalking (somnambulism)
slow-wave sleep problem
different to acting out dream but can engage in complex behaviours
more common in children
Genetic component
Night terrors
- Night terrors (pavor nocturnus)
➢ Anguished screams, trembling, a rapid pulse, and usually
no memory of what caused the terror
➢ Hereditary element
Bedwetting (nocturnal enuresis)
➢ About 10% of 7 year olds
➢ Heredity element
Fatal Familial Insomnia
Neurodegenerative condition
* Prion disease
* Damage to the thalamus
Initially presents with insomnia and very vivid dreams when the person finally manages to sleep.
- Psychiatric complications – panic attacks, cognitive deficits, paranoia and phobias
As Fatal Famillial Insomnia progesses, it affects
EEG shows
what happens to sleep scycle
Final symptoms
the autonomic nervous system (e.g. elevated blood pressure) and coordination (ataxia)
disturbances and reductions in sleep spindles and K complexes
Dissapearance of slow wave sleep and only brief periods of REM sleep
Ultimately leads to inability to speak or move (akinetic mutism), coma and death
