Term
| What are some characteristics of sleep (Human)? |
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Definition
| Recumbent posture, raised sensory thresholds, decreased motor output, dreaming |
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Term
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Definition
The simultaneous monitoring of physical activities during sleep.
EEG (brain waves), EKG (Heart activity)
EMG (Muscle activity), EOG (Eye activity)
Blood pressure and O2 level
Respiration |
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Term
| Describe NREM sleep sensation and perception. |
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Definition
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Term
| Describe Awake sensation/perception |
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Definition
| Vivid, externally generated (input from eyes, mouth, ears) |
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Term
| Describe REM sleep sensation and perception. |
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Definition
| Vivid, internally generated (not input from sensory organs) |
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Term
| What is the major difference between thought patterns in NREM + Awake behavior versus REM sleep? |
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Definition
NREM/Awake -> Logical
REM -> Illogical |
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Term
| What are the thought states for each stage of arousal/sleep behavior |
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Definition
Awake -> logical/progressive
NREM -> Logical/repetitive
REM -> Illogical/bizarre |
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Term
| What are the different movement command states for the different awake/sleep stages? |
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Definition
Awake -> Continuous, voluntary
NREM -> Episodic, involuntary
REM -> Commanded, but inhibited (except eyes) |
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Term
| How many phases of NREM sleep are there? |
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Definition
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Term
| Characterize NREM sleep behavior. |
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Definition
Slow brain waves, no awareness of outside world
Increase sensory threshold
Decreased heart rate, blood pressure
Increased neuroendocrine activity, especially growth/sex hormones |
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Term
| What is the first stage of NREM like? |
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Definition
slower EEG, low voltage, mixed frequencies.
Theta waves dominant |
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Term
| Describe the shape of a theta wave |
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Definition
High frequency, low amplitude waves
looks like a buzz |
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Term
| Describe what an alpha wave looks like. |
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Definition
An alpha wave consists of high frequency, and medium amplitude waves.
Looks like noise (correlates with an awake state) |
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Term
| Describe the second stage of NREM |
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Definition
| K-complexes and sleep spindles (12-14 hz) |
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Term
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Definition
Viewed in EEG, large biphasic amplitude modulation
Looks like QRS wave in EKG |
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Term
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Definition
higher frequency waveforms embedded on a lower frequencuy wave. Viewed easiest in Stage 2 of NREM sleep.
Looks like fused muscle tetany. |
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Term
| Describe stage 3 + 4 of NREM sleep. |
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Definition
Low frequency, high amplitude delta waves (2 hz max) for both stages
Stage 3 has a smaller population of theta waves with the delta waves
Stage 4 is purely delta waves |
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Term
| What are some characteristics of REM sleep? |
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Definition
Relaxed muscles (atonia)
Rapid Eye Movements
Loss of control of temperature and cardiopulmonary functions
vivid dreaming |
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Term
| How much time is spent in REM sleep across young age, middle age, and elderly persons? |
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Definition
The same amount of time!
If you miss it, you must make it up. |
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Term
| Describe the old wrong hypothesis of sleep. |
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Definition
Bremer: sleep is a reaction to the lack of sensory input.
He hypothesized this after decerberalizing cats: no sensory cortex went into a sleep like state. |
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Term
| Describe the Hess theory of sleep. |
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Definition
Active process
Related to thalamocortical system |
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Term
| What are the two mechanisms for regulating the sleep/wake cycle? |
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Definition
Circadian rythym (higher probability of falling asleep later in the day)
Homeostatic property (increases as you have not slept, adenosine in mamals? people who don't sleep die) |
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Term
| What are the sequence of events in sleep? |
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Definition
1. Relax cortical waking mechanisms (slow EEG down)
2. Incomplete relaxation of areas controlling muscles (twitching)
3. Inhibit histimine producing hypothalamus (anti-histamines put you to sleep)
4. Early NREM - spindles created by interconnected corticothalamic activity, occasionally into burst mode
5. Late NREM -> spindle diminishes, hyperpolarized thalamocortical neurons, spontaneous delta waves. People are groggy when arising from this step. |
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Term
| What are circadian rythyms? |
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Definition
| Daily biological rythyms representing an adaptation to a light/dark cycle, but can operate independently of external cues. |
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Term
| Why does the circadian rythym shift later over days in the absence of light/dark cues? |
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Definition
| The rythym is a cycle slightly longer than 24 hours. |
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Term
| What is the suprachiasmic nucleus' role in circadian rythyms? |
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Definition
| Master pacemaker. If lesioned, the same amount of time is spent in both active/non-active phases, but completely arrythymic. |
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Term
| How does information flow in the mammalian circadian rythym? |
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Definition
| Retinal-hypothalamic tract -> suprachiasmic nucleus -> output pathways (everywhere) |
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Term
| What does the intergeniculate nucleus do? |
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Definition
| coordinates the influence of the circadian rythym |
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Term
| Aside from the suprachiasmic nucleus, what are the targets of the intrinsically photosensitive retinal ganglion cells? |
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Definition
| ventral LGN -> Intergeniculate leaflet -> olivary pretectal nucleus |
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Term
| Describe the basic functioning of suprachiasmic nucleus cells. |
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Definition
If SCN is input/output cut, there is still circadian behavior
Separate SCN cells have individual, rythymic firing rates
Transplant SCN between animals, new animal inherits the other's circadian rythym. |
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Term
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Definition
| ability to alter circadian rythym using external cues (such as light) |
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Term
| Describe the flow of action in the drosophilla circadian rythym. |
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Definition
1. Per and Tim proteins are synthesized
2. Per-Tim dimers form in cytoplasm, undimerized per is degraded by DBLTim protein
3. Per-Tim dimers migrate into nucleus, bind to Clk and Cyc on Tim and Per promoters, stopping production of Tim and Per
4. When activated by light, Cryptochrone in the nucleus degrades the Tim very quickly, and the DblTim degrades the Per slowly, slowly returning production of Tim and Per. |
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Term
| What is the function of DblTim in the fly circadian cycle? |
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Definition
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Term
| What is the function of Cryptochrome in the fly circadian cycle? |
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Definition
| Activated by light, destroys the Tim proteins |
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Term
| How does the circadian cycle work in mammmillian clock cells compared to a fly's clock cell? |
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Definition
Similar to drosophillia, but a few differences
clk-BMA1 promote transcription of Per and Cry (instead of Clk-Cyc promoting Per and Tim)
Per-Cry dimers form instead of Per-Tim
Casein Kinases Epsilon and delta take the role of Dbt and Sgg |
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Term
| What are the major outputs and the functions of the suprachiasmatic nucleus? |
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Definition
Mainly to subparaventricular zone, sleep
Basal Forebrain, Thalamus -> memory, rewards
Paraventricular nucleus -> autonomic regulation
Preoptic, anterior hypothalamus areas -> thermoregulation, reproductive function
Posterior hypothalamus areas -> sleep-wake cycle, prolactin, growth hormone. |
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