L16 Emotion And Motivation Flashcards
What is behaviour influenced by?
Internal states
What are the 4 Fs of internal state?
- Feeding
- Fighting
- Fleeting
- Mating ( I think he meant Fu**ing)
What does Perturbation mean?
It refers to a small change or deviation in the regular motion or state of a system, often caused by an external influence.
What is leptin?
Leptin is a hormone produced by adipose tissue (body fat) that reduces fat.
How does Leptin reduce body fat?
Leptin increases metabolic rate to which it decreases body fat
Less leptin = less body fat
What changes are caused by ob/ob leptin mutations?
ob/ob mutant mice lack leptin and get obese. But if you link an ob/ob mouse’s bloodstream with a normal mouse, it gets thin again
Which part of the brain is responsible for anorexigenic (loss of appetite) and orexigenic (appetite stimulating)?
Lateral hypothalamus - hunger (orexigenic)
Ventromedial nucleus - satiety (anorexigenic)
What two hormones does the lateral hypothalamus secrete in regulating appetite and feeding behaviour?
Orexin and MCH
What hormones are expressed in the Arcuate nucleus (within the hypothalamus)?
- POMC/αMSH/
CART inhibit the lateral hypothalamus - NPY/AgRP stimulates the lateral hypothalamus
Lateral hypothalamus stimulates hunger (more eating)
How does Leptin affect eating behaviours?
Leptin:
- stimulates POMC/αMSH/CART
- Inhibits NPY/AgRP
What effects does POMC/αMSH/
CART and NPY/AgRP have on the paraventricular nucleus?
POMC/αMSH/
CART stimulates paraventricular nucleus but NPY/AgRP inhibits it
Opposing effects for lateral hypothalamus
Does the paraventricular nucleus inhibit or stimulate hunger?
It inhibits hunger (gives you the feeling of being full)
Only lateral hypyothalamus promotes an appetite
How does the hormones within the Arcuate nucleus affect the ANS?
- POMC/αMSH/
CART stimulates the SNS (stimulates metabolic rate) - NPY/ AgPR stimulates PNS (inhibits metabolic rate)
How does the pituitary gland increase metabolic rate?
The paraventricular nucleus (in hypothalamus) activates the pituitary gland to which it secretes TSH/ACTH which stimulates metabolic rate
How does blood glucose promote/inhibit eating?
Blood glucose can inhibit the lateral hypothalamus and stimulate ventromedial nucleus
How does drug GLP-1 help people lose weight by reducing appetite?
Induces insulin secretion which secretes POMC/αMSH/CART which inhibts the lateral hypothalamus which can reduce that hunger
How does the digestive system affect eating behaviours?
When stomach is full - blood glucose increases, body fat increases and leptin is produced or it can inhibit Ghrelin
What does Ghrelin do?
Ghrelin stimulates NPY/AgRP which stimulates the lateral hypothalamus/inhibits paraventricular nucleus
Why do we have an odd number of inhibitory arrows in the loop?
There is an odd number of inhibitory arrows in the feedback loops because realistically we can’t keep eating therefore there must be one more inhibitory route that allows us to stop eating when we are full
When is CCK produced and what are the effects?
When stomach full = nutrients in intestines = CCK released = activates receptors on solitary nucleus (brainstem) which inhibits eating
Is the signalling produced by neuroleptics and hormones slow or fast?
They are slow
What is the difference between unconditioned stimulus and a conditioned stimulus?
Unconditioned stimulus (UCS) is a stimulus that naturally and automatically triggers a response without any learning
Condition stimulus - Previously a neutral stimulus which comes to a learnt stimulus for example bell ringing before food is presented makes dog salivate.
What happens if you stimulate the medial/ lateral part of the hypothalamus?
- Medial hypothalamus - affective aggression
- Lateral hypothalamus - predatory aggression
Difference between affective and predatory aggression
- Affective - driven by strong emotions such as anger, fear, or frustration
- Predatory - driven by desire to obtain a goal, such as food or resources
