Sleep and Emotion Flashcards
What plays a crucial role in regulation of sleep-wake cycle?
5 single source divergent networks (SSDN)
Are the neural circuits that mediate each state (sleep or wake) distinct from one another or not?
They are distinct but also interdependent
The circuits that promote arousal and those that promote sleep must be what in order for the sleep-wake cycle to proceed?
separate
What are the stages of the sleep-wake cycle?
Awake
Non-REM sleep
REM sleep
What is the wake stage of sleep-wake cycle?
individual is conscious and all five SSDNs are active
How is non-REM sleep cycle triggered?
by the release of adenosine from glial cells
How is non-REM sleep characterized?
the activity of the noradrenergic (NE/NA) neurons in the locus coeruleus and the serotonergic (5-HT) neurons in the Raphe nuclei
How many stages are within Non-REM sleep?
4
What is stage 1-2 of non-REM sleep?
light sleep
What is stage 3 of non-REM sleep?
moderate-deep sleep
What is stage 4 of non-REM sleep?
deepest level of sleep (slow-wave sleep)
What happens after the 4th stage of non-REM sleep?
individual enters REM sleep
What is REM sleep often marked by?
vivid hallucinations
What initiates the effects of REM sleep?
activation of cholinergic (ACh) neurons in the pons (PPN)
What is responsible for the relative physical paralysis that occurs during REM sleep?
Increased activity of GABAergic neurons in the reticular formation (pons) which send projectionsto inhibitory neurons that synapse on LMNs (lower motor neurons) in the spinal cord
How are EEGs of REM sleep compared to awake?
they are very similar in appearance
On average how many periods of REM sleep will an individual cycle through per sleep-wake cycle?
~4
What can eventually occur in response to severe sleep deprivation?
death
REM sleep during development?
comprises a high percentage of the sleep-wake cycle than observed in adults
What occurs following sleep deprivation?
REM rebound
What is REM rebound?
Total number of hours of sleep lost may not be made up but REM will be made up by an increased % of the sleep-wake cycle being devoted to REM
What are some observations that link REM sleep with memory consolidation?
- Increased % of REM sleep during intense periods of mental activity
- Same neural firing patterns were observed in the brains of rodents while they were awake an learning a spatial task and while they were in REM sleep following the task
- Deficits in memory are observed following REM deprivation
What does research evidence say about the importance of non-REM sleep?
it’s important for conservation of energy and restorative for the mind and not necessarily for the body
Effects of sleep deprivation on exercise?
Sleep deprived were able to exercise as effectively as those who weren’t
- but cognitive impairment was present
What are some roles of sleep and energy conservation?
- During wakefulness, the repeated release of NTs can deplete glial cell energy storage (glycogen)
- When these energy stores are depleted, the glial cells release adenosine
- R/cs in the cerebral cortex, thalamus, and brainstem bind adenosine which promotes the induction of non-REM sleep
- Periods of non-REM sleep throughout the sleep-wake cycle replenish the glycogen stores of the glial cells
What is the idea of “Brainwashing” during sleep?
During sleep, cells within the brain contract creating extra space.
- Allowing CSF to flow between the brain cells and deposit waste into the vasculature
What neurological diseases have been associated with disruption of the waste removal process and accumulation of metabolic waste?
Alzheimer’s disease and its associated amyloid beta plaques
What is the process of emotion mediated through?
through the 5 SSDNs
What is activated to generate emotional mood and affect?
networks that underlie positive and negative emotions
What are positive emotions modulated through?
Dopamine (DA) system
The dopaminergic neurons of the (VTA) in the brainstem send projections to where?
the basal forebrain, specifically to the nucleus accumbens (nAc)
Excitatory input from the dopaminergic neurons activates what? and inhibits?
activates –> nucleus accumbens (nAc)
inhibits–> activity of the amygdala
Where else does the VTA project (directly/indirectly through nAc) when activated?
- medial prefrontal cortex
- ant/post areas of cingulate gyrus (ant/post CG)
- insula
What is the purpose of the medial prefrontal cortex (Med PFc)?
aids in the process involved in working memory related to positive emotion
What is the role of the anterior and posterior areas of the cingulate gyrus (ant/post CG) in positive emotion?
focuses on attention
What is the role of the insula in positive emotion?
aids in modulation of all emotions
What are negative emotions processed through?
norepinephrine/noradrenalin (NE/NA) and serotonin (5-HT)
What parts of the brainstem sends excitatory projections to the amygdala?
Raphe nuclei (nR) and locus coeruleus (Lc) along with neurons with the periaqueductal gray
What does activation of the amygdala do?
suppress the nAc (nucleus accumbens)
What regions of the cortex will the Lc, nR, and PAG directly send projections (negative emotion)?
- Prefrontal cortex (Orb PFC)
- Anterior cingulate gyrus (ant CG)
- insula
What is the role of the orbital prefrontal cortex (Orb PFC) in negative emotion?
processes working memory related to negative emotion
Look at chart “Neural Networks Underlying Emotion”
pg 32
