Term
| a/an (free running condition/entrained condition) is entrained to a light and dark cycle |
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Definition
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Term
| where is the circadian clock located in the brain? |
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Definition
| suprachiasmatic nucleus of the hypothalamus |
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Term
| primary input to the suprachiasmatic nucleus (SCN) is from? |
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Definition
| the retina of the eye - travels via the retinoypothalamic tract |
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Term
T or F
Individual SCN cells are capable of producing self-sustained rhythms even when dissociated due to a series of transcriptional/translational feed back loops. |
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Definition
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Term
| light comes in through the retina and activates _____ cells, which then synapse onto the ___ neurons |
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Definition
| Light comes in through the retina and activates retinal ganglion cells, which then synapse onto the SCN neurons |
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Term
| light comes in through the retina and activates _____ cells, which then synapse onto the ___ neurons |
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Definition
| Light comes in through the retina and activates retinal ganglion cells, which then synapse onto the SCN neurons |
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Term
| neurons fire in the SCN more during the (day/night) |
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Definition
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Term
| what are the firing patterns of SCN neurons? |
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Definition
| They fire during the day, their firing is synchronized to one another |
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Term
| Are the SCNs of diurnal and nocturnal animals different? |
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Definition
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Term
| a lesion to the SCN does what to sleeping patterns |
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Definition
| disorganizes sleeping patterns (loss of circadian rhythms) |
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Term
| what type of light is melanopsin selective for? |
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Definition
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Term
| After implanting wild-type fetal SCN tissue into a mutant hamster with a lesioned SCN, the circadian rhythm will be (wild-type/mutant) |
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Definition
| wild-type - the lesioned hamster's SCN takes on the circadian rhythm of the donor tissue |
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Term
| retinal ganglion cells with photoreceptors (and melanopsin) are called ____ |
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Definition
intrinsically photosensitive retinal ganglion cells
(ipRGCs) |
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Term
| Intrinsically photosensitive retinal ganglion cells (ipRGCs) are important for what visual functions? |
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Definition
NON- IMAGE FORMING VISUAL FUNCTIONS
1. Entrainment to the light/dark cycle
2. Pupillary Light Restriction
3. Melatonin supression |
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Term
| melatonin is secreted by what area of the brain? At what times? What controls rhythm of secretion? |
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Definition
pineal gland
high secretion at night
SCN controls secretion rhythm |
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Term
| Giving a light pulse during early night, you get phase shift to the (R/L) causing you to wake up (earlier/later) the following day |
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Definition
| Light pulse early night, phase shift to right, wake up earlier |
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Term
| Giving a light pulse during late night, you get phase shift to the (R/L) causing you to wake up (earlier/later) the following day |
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Definition
| Light pulse late night, phase shift to left, wake up earlier |
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Term
| along with input from the retina, the SCN also receives input from where? What are these important for? |
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Definition
the intergeniculate leaflet thalamus
median and dorsal raphe nucleus (serotonin)
Important for arousal and activity |
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Term
| A 56-year-old man has retinitis pigmentosa with bilateral posterior subcapsular cataracts and is clinically blind. Since he has a selective loss of the functional outer retina (rods and cones), which of the following visual processes are likely disrupted? |
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Definition
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Term
| The activation of the molecular clock begins when the protein dimer clock in ____ binds to the promoter region of the ___ genes in the cryptochrome genes. |
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Definition
| The activation of the molecular clock begins when this protein dimer clock in BMAL1 binds to the promoter region of the PERIOD genes in the cryptochrome genes. |
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Term
| Period genes activate (positive/negative) transcription for the molecular clock protein products can then dimerize with themselves – so |
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Definition
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Term
| ___ and ___ dimerize with each other, allowing them to translocate back into the nucleus where they can directly interact with BMAL1 and shut off their own transcription. |
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Definition
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Term
| PER and CRY are (positive/negative) regulators of the molecular clock |
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Definition
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Term
PER and CRY are high in the SCN during the (day/night).
BMAL1 is high during the (day/night) |
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Definition
PER and CRY are high in the SCN during the day
BMAL1 is high in the SCN at night |
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Term
T or F
When separated from one another SCN neurons do not fire |
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Definition
| False - SCN neurons fire every 24 hours in vitro, even though they are not communicating with one another |
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Term
| What are the positive regulators (activators) of the autoregulatory feedback loop that comprises the molecular circadian clock? |
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Definition
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Term
| What are 4 examples of SCN output mechanisms? |
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Definition
1. Body temperature regulation
2. Autonomic nervous system function
3. Sleep and arousal
4. Hormone rhythms (i.e cortisol) |
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Term
| cortisol levels are (high/low) right before you wake up and (high/low) when you go to bed |
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Definition
cortisol levels high right before you wake
cortisol levels very low right before you go to bed |
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Term
T or F
The SCN has many outputs that control not only sleep/wake cycles, body temp, hormones, and autonomic nervous system, but also controls peripheral rhythms in organs such as the kidney, the liver, and even fat cells |
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Definition
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Term
T or F
Nearly all cells in the body, and many brain areas, have their own circadian clocks |
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Definition
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Term
T or F
Shift workers are at an increased risk for certain types of cancer (esp. breast), reproductive problems, cardiovascular disease, and psychiatric disorders |
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Definition
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Term
T or F
There are many oscillators (internal clocks) throughout the brain and body, including in peripheral organs such as the heart, lung, kidney, liver, etc. But none of these oscillators are self-sustainable and require input from the primary pacemaker in the hypothalamus, the suprachiasmatic nucleus (or SCN) |
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Definition
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Term
As you eat throughout the day, leptin (increases/decreases)
Decreased leptin will (increase/decrease) appetite and (increase/decrease energy), which can lead to ____ |
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Definition
As you eat throughout the day, leptin increases
Decreased leptin will increase appetite and decrease energu, which can lead to obesity |
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Term
| altered sleeping patterns can decrease what protein, leading to obesity? |
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Definition
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Term
T or F
circadian misalignment could be how some of what the metabolic obesity and metabolic syndrome problems (perhaps diabetes) are caused in shift work. |
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Definition
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Term
T or F
Studies with mice show that the immune system is largely unaffected by changes in circadian rhythms |
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Definition
False
- Changes in circadian rhythms along with LPS injection caused higher mortality in mice with induced "jet lag" |
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Term
| sleep is controlled by default wake-promoting centers, so your default state is (asleep/awake) |
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Definition
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Term
| Benadryl puts you to sleep is because the ___ ____nucleus is a histaminergic part of the wake-promoting system. |
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Definition
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Term
T or F
If you inhibit the histamine system in the ascending arousal system, you will activate the wake promoting system |
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Definition
| False - inhibiting the histamine system (such as with the antihistamine benadryl) will block the wake promoting system--making you sleepy |
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Term
| ___ neurons are found in this region of the brain involved in narcolepsy |
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Definition
| Orexin neurons are found in the lateral hypothalamus, which is involved in narcolepsy |
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Term
The ___ nucleus is involved in shutting off the wake signal (getting to sleep).
What type of interneurons are located here? |
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Definition
| preoptic nucleus with GABAergic interneurons |
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Term
| lesions of the mid-pons block GABAergic signal going to the raphe nucleus and locus coerulus, which blocks (wake/sleep) promoting signal |
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Definition
| blocks the wake promoting signal |
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Term
neurotransmitters?
1. Locus coeruleus
2. raphe nucleus
3. reticular formation |
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Definition
locus coeruleus - norepinephrine
raphe nucleus - serotonin
reticular formation - acetylcholine |
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Term
| a lesion of the brainste/forebrain junction can cause what? |
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Definition
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Term
| anterior hypothalamus lesions can cause what? |
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Definition
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Term
in REM sleep, you get increases in what neurotransmitter?
decreases in what neurotransmitter? |
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Definition
acetylcholine increases
adrenaline decreases |
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Term
T or F
Some evidence suggests that something is happening in sleep to strengthen synapses or prune synapses that aren’t needed, to enhance your memory. |
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Definition
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