Neurobiology of Feeding Behavior

Question 1

This nerve conveys information to

the brain about the stretching of the stomach walls.

Answer 1

Vagus nerve (cranial nerve X)

Question 2

Part of small intestine adjoining the stomach. Major its for absorbing nutrients.

Answer 2

Duodenum

Question 3

Nerves from the duodenum inform the brain about ___.

Answer 3

Tells brain about distension, and type and amount of nutrition.

Question 4

Distension of the duodenum releases the hormone

___.

Answer 4

Cholecystokinin (CCK) is released by ___ when ___.

Question 5

CCK limits meal size by,

1. Constricting ___ between ___ and ___.
2. Stimulating ___ to send signals to the ___.

Answer 5

1. ___ the sphincter muscle between the stomach and the duodenum.
2. ___ the vagus nerve to send signals to the hypothalamus.

Question 6

CCK limiting meal size by constricting the sphincter muscle causes the following effects.

Answer 6

The stomach to hold its contents and fill more quickly than usual. Stomach distension is hastened. This is caused by ___, which is caused by ___.

Question 7

CCK limiting meal size by stimulates the vagus nerve to send signals to the hypothalamus causes ___.

Answer 7

Cells in hypothalamus release a neurotransmitter that is a shorter version of the molecule itself, is an effect of signals from the ___ stimulated by ___ (molecule).

Question 8

CCK has ___ term effects

Answer 8

Has short term effects. It limits the size of the

meal, but an animal that has eaten a smaller than usual meal compensates by overeating at the next meal.

Question 9

The pancreas releases ___, which enables glucose to enter the cells.
It also releases ___, which stimulates the liver to convert some of its stored glycogen back to glucose.

Answer 9

Insulin, released by the ___, enables ___ to ___.

Glucagon, also released from the ___, stimulates ___ to convert ___ to ___.

Question 10

This hormone signals your brain about your fat reserves. More fat cells = ____

Answer 10

Leptin signals brain about ___. ___ fat cells = more leptin

Question 11

Triggers onset of puberty

Answer 11

Additional functions of leptin other than signaling brain about fat reserve.

Question 12

In the hypothalamus.
Has one set of neurons sensitive to hunger signals
Second set sensitive to satiety signals

Answer 12

arcuate nucleus
Where is it?
It has two sets of neurons; what are their functions?

Question 13

Input to ___

ghrelin, insulin, leptin, taste input

Answer 13

Hunger sensitive cells in the arcuate nucleus receive input in the form of? (hint: One NT, two hormones, one sensory.)

Question 14

This neurotransmitter:
Stomach releases it during a period of food deprivation
Acts on the hypothalamus to increase appetite

Answer 14

Ghrelin is released by ___ during a period of ___, and acts on ___ to ___.

Question 15

Neurotransmitter CCK, a short-term signal. 
Blood glucose (a short-term signal) directly stimulates  and prompts the pancreas to release insulin, which also stimulates (intermediate-term). 
Body fat releases leptin, a long-term signal. 
Nicotine also stimulates

Answer 15

Satiety sensitive cells in the arcuate nucleus receive input in the form of?
List two short-term, one intermediate, one long-term signal

Question 16

Much of the output from the arcuate nucleus goes to the ___ of the hypothalamus

Answer 16

paraventricular nucleus (PVN) of the ___ receives much of input from ___?

Question 17

hunger cells in the arcuate nucleus ___ the paraventricular nucleus (PVN)

Answer 17

paraventricular nucleus is ___ inhibited by the ____

Question 18

paraventricular nucleus ___ the lateral

hypothalamus

Answer 18

The lateral hypothalamus is inhibited by the ___

Question 19

GABA, neuropeptide Y (NPY), agouti-related peptide (AgRP) are ___ transmitters used by ___ and ___ to inhibit ___ and ___.

Answer 19

Hunger cells and PVN use these three inhibitory transmitters to inhibit the PVN and lateral hypothalamus, respectively.

Question 20

Melanocortins and glutamate are ____ transmitters used by ___ to ___.

Answer 20

Satiety-sensitive neurons use these excitatory transmitters to stimulate the PVN.

Question 21

1. increases animals’ persistence in seeking food
2. increases activity and motivation in general
   (Also causes wakefulness (lack = narcolepsy))

Answer 21

Orexin is released by lateral hypothalamus to
1.
2.

Question 22

Three hormones that increase satiety:

One hormone that increases hunger:

Answer 22

Insulin, CCK, and leptin all ___/

Ghrelin ___.

Question 23

Three functions of ___:

controls insulin secretion, alters taste responsiveness, and facilitates feeding (ingestion and swallowing)

Answer 23

Three functions of the lateral hypothalamus.

Question 24

Stimulation of the lateral hypothalamus ___.

Damaging the lateral hypothalamus ___.

Answer 24

Stimulating it increases the drive to eat.

Damaging it causes refusal of food and water, but gradually recovers if kept alive through force-feeding.

Question 25

Lateral hypothalamus facilitates feeding by
1.
2.
3.

Answer 25

___ facilitates feeding by

1. Activity　→ improves taste
2. enhances cortical responses to food
3. increases secretions of insulin and digestive juices

Question 26

Output from the ventromedial hypothalamus (VMH) ___ feeding

Answer 26

Output from the ___ (VMH) inhibits feeding.

Question 27

Damage to VMH results in ___.
Animals with damaged VMH have stomachs that ___.
Damage to VMH causes increase in insulin production, which results in ___.

Answer 27

Damage to ___ results in animals overeating and weight gain because they eat more frequently.
Animals with damaged ___ have ___ that empty faster.
Damage to ___ causes ___ in insulin production, which results in the animal storing much of its meals as fat, but not feeding the cells that need the nutrients.

Question 28

Damage to PVN cause rats to ___.

Animals with damaged VMH eats ___.

Answer 28

Damage to ___ cause rats to eat larger than average meals.

Animals with damaged ___ eats larger meals.