II. Study Guide for Exam IIIA. Lecture 20—Hunger and Eating Behaviors1. Know the different hypothalamic nuclei involved in regulating hunger and satiety and which they are involved in regulating (hunger, satiety, or both)a. Lateral hypothalamus – hunger centerb. Ventromedial hypothalamus & Paraventricular nucleus – satiety centersc. Arcuate Nucleus – regulates both hunger and satiety 2. Know the neurotransmitters associated with the satiety pathway and the neurotransmitters associated with the hunger pathwaya. Neuropeptide Y – hunger and satietyb. CRH – satietyc. Orexin – hunger d. Melanocyte stimulating hormone (MSH) – satiety 3. Know the different hunger and satiety signals and what increases their levels.a. Satietyi. Cholecystokinin (CCK) – a peptide released by the stomach when it has food in it ii. Glucose – blood levels rise during absorptioniii. Insulin – released by pancreas during absorption; due to an increase in blood sugariv. Serotonin – increased by absorption of tryptophan v. Leptin – released by fat cells when they are taking up fat b. Hungeri. Ghrelin – a peptide released by the stomach when empty ii. Low glucose – low blood sugar triggers hungeriii. Endocannabinoids – their production in the hypothalamus is inhibited by leptin; inhibit CCK release and CRH neurons thus decreasing satiety and stimulate hunger4. Be able to describe the consequences of defects in leptin signaling and how this is related to human obesity.a. Defects in the leptin gene (don’t produce leptin when fat cells take in fat) and receptor have lead to obesity and increased eating (hyperphagia) in mice but no mutations have been identified in obese humans. Some have normal leptin levels while some are normal; therefore most human obesity is environmental, not genetic. 5. List and define the factors influencing what, when, and how much we eat besides the hunger and satiety circuit.a. Whati. Taster preference – genetic and learnedii. Cultural and geographicaliii. Socioeconomic factors – what foods we can affordiv. Habits and family traditionsv. Emotionsvi. Advertising and packaging b. Wheni. Memoryii. Work schedulesiii. Family traditions or routinesiv. Cultural normsv. Personal preferences and habitsvi. Food availability c. How muchi. Social influence ii. Cafeteria effect – eating one food decreases desire for it but continue eating because other foods availableiii. Appetizer effect – eating small amount of food first increases hungeriv. Cultural norms – how long means are, eating till full or till not hungryv. External/visual cues- plate/portion size6. Know the role of the mesolimbic pathway in eating behaviors and how it may be defective in obesitya. Neurons in the ventral tegmental area release dopamine onto neurons in the hippocampus, nucleus accumbens, and frontal cortex  this release is associated with reward or pleasure b. Dopamine is involved in the wanting aspects of reward or pleasure and is triggered by hungerc. In obese people dopamine receptor levels are decreased which may cause them to overeat to compensate for the lower level of pleasure the receive from eatingd. Or in obese people that binge eat, too much dopamine may be released which causes them to receive higher than normal wanting stimulation i. Goldilocks Principle of dopamine “too much or too little might lead to overeating” 7. Know the 3 additional brain regions that influence eating behaviors and how they influence them.a. Amygdala – part of the limbic system that regulates emotions; may provide input to the hypothalamus about food aversions, emotional states, stress, etc.b. Hippocampus and the medial temporal lobe – parts of the brain important for memory storage; may provide input to the hypothalamus about how recently we ate, how filling it was, how nutritious and good tasting it was, and learned cravings etc.c. Inferior frontal love – receives input from the olfactory bulb about smells and possibly from nuclei about taste that may provide input to the hypothalamus about pleasurable sensory information related to food B. Lecture 21—Sleep and Circadian Rhythm1. Be able to compare and contrast the pattern of EEG waves between wakefulness and the two different types of sleep.a. Wakefulness – small and rapid EEG wavesb. NREM – larger, slower EEG wavesc. REM – small and rapid EEG waves2. Know the EEG, EOG, and EMG patterns of wakefulness, NREM sleep, and REM sleep and be able to recognize what state of sleep/wakefulness someone is in if given a description of their EEG, EOG, and EMG patterns.a. Wakefulness – short, rapid EEG (activity in brain) waves, high EOG(eye movement) activity, high EMG (muscle activity)activityb. NREM – larger, slower EEG waves, less EMG activity, no EOG activityc. REM – short, rapid EEG waves no EMG activity, high EOG activity 3. Know the different characteristics of REM vs. NREM sleep.a. NREMi. Larger, slower EEG waves, less EMG, no EOGii. Accounts for most of sleep in adultsiii. Characterized by the most movementiv. Much less dreaming but night terrors are common b. REMi. Short, rapid EEG, no EMG, high EOGii. Muscles twitch but large movements are not commoniii. Eyes show rapid eye movementsiv. Accounts for about 2 hours of sleep in adults (amount increases as sleep increases)v. Characterized by much more dreaming 4. Know the arguments for and against the need for REM sleep.a. Fori. Nearly all mammals and many birds appear to have Rem sleepii. When deprived of REM sleep experience REM rebound – increased tendency to go into REM sleep and have more REM sleep per sleep sessionb. Againsti. Some animals, whales, seem to have very little REMii. Nearly all antidepressants suppress REM sleep partly or completely and patients are fine5. Know the different characteristics of dreaming and its hypothesized function.a. Characteristicsi. Everyone dreams (typically multiple times a night)ii. All mammals and birds do or at least have REM sleepiii. Take place in real timeiv. Sensory info is occasionally incorporated v. Often contain conflict or negative emotional statesb. Functioni. Manifestation of our subconscious wishes, desires, and fears ii. Memory pruning and consolidation iii. Rehearse responses or to develop solutions iv. Dreams are meaningless brain activity 6. Know the different proposed functions of sleep and the arguments for and against them.a. Important for consolidation of implicit and explicit memoryb. Means to solve