Friday, 4-8-DSA-Smell and Taste (Karius)

Question 1

__ receptors are located on the cilia that protrude into the mucus layer.

Answer 1

odorant

Question 2

Odorant receptors are ___ receptors that create cAMP to open a cyclic-nucleotide gated ion channel.

Answer 2

GPCR

-G protein is a Gs protein, but specific to olfactory receptors

Question 3

If an odorant persists for more than a few minutes, the sensitivity of the channel to the cAMP is reduced, decreasing __ entry. A smaller generator potential results, reducing the probability of an AP in the axon

Answer 3

Na and Ca

Question 4

How do odorants produce a characteristic odor?

Answer 4

each odorant activates different combinations of odorant receptors to produce its characteristic odor

Question 5

Describe the binding of odorants by odorant receptors at higher concentrations:

Answer 5

ODORANT CONCENTRATION CHANGES PERCEIVED SMELL
-At higher concentrations, the odorant starts to bind to receptors with a lower affinity for the odorant in addition to the receptors with a higher affinity

Question 6

This type of odorant receptor seems to produce physiologic/endocrine responses to pheromones

Answer 6

TAARs

Trace Amine-Associated Receptors

Question 7

List the 5 layers of the olfactory bulb:

Answer 7

• Olfactory n. layer
• Glomerular layer
• External plexiform layer
• mitral cell layer
• granule cell layer

Question 8

What cell types are found in the glomerular layer of the olfactory bulb?

Answer 8

Periglomerular cells

Question 9

What cell types are found in the external plexiform layer?

Answer 9

Tufted cells

Question 10

What cell types are found in the mitral cell layer?

What cell types are found in the granular cell layer?

Answer 10

mitral cells

Granule cells

Question 11

Within the olfactory bulb there are glomeruli where the axon terminals synapse using ___ as a NT

Answer 11

EAA

Question 12

What are the 3 post-synaptic neurons found in the glomeruli where axon terminals from olfactory neurons synapse? Which ones go to the olfactory cortex and which will remain in the olfactory bulb?

Answer 12

• mitral cells-go to olfactory cortex
• tufted cells-go to olfactory cortex
• periglomerular cells-remain in olfactory bulb

Question 13

The __ cells release GABA at their synaptic contacts with other glomeruli and inhibit the activity from these glomeruli. This means that the odorant producing the strongest stimulation will suppress the input from other glomeruli that weren’t as strongly activated and improve the signal specificity in the brain

Answer 13

periglomerular

Question 14

The __ cells release GABA at their synaptic contacts but they synapse with the mitral and tufted cells. It is believed that they also work to increase the specificity of the message going to the olfactory cortex

Answer 14

granular

Question 15

The first possible synapse in the olfactory cortex is in the __. These synapses relay the information to the contralateral side and axons may also continue on the ipsilateral side

Answer 15

anterior olfactory nucleus

Question 16

In addition to the anterior olfactory nucleus, the olfactory cortex also contains these cortices:

Answer 16

• piriform cortex

- lateral entorhinal cortex

Question 17

This output from the olfactory cortex projects to the hippocampus, which is important in memory formation. Olfactory input facilitates both memory info and recall

Answer 17

entorhinal cortex

Question 18

This output from the olfactory cortex projects to the lateral hypothalamus, which is important in control of appetite. Olfactory inputs can influence appetite

Answer 18

piriform cortex

Question 19

The __ cortex can project to the medial orbitofrontal cortex (VIA THE THALAMUS) to provide info that will be used to ID the flavors of foods, among other things

Answer 19

piriform

Question 20

The ___ can send input BACK TO the olfactory epithelium/bulb to modify the receptor responses to odorants

Answer 20

olfactory cortex

Question 21

Sour tastes are produced when the H ion enters the taste bud via ___

Answer 21

H+ channel

Question 22

Salty tastes are produced when Na or Ca enter the taste bud via __

Answer 22

Na or Ca channel

Question 23

The umami (savory) taste receptor is a __ receptor and activated by the AA ___

Answer 23

• metabotropic glutamate

- glutamate

Question 24

Taste buds for sweet and bitter flavors use a __ system to depolarize the cell but are not directly related to the metabotropic receptors that detect the umami sensation

Answer 24

2nd messenger

Question 25

Gustatory inputs travel a straight-forward path to the brain. There are synapses in the: ___

Answer 25

• NTS
• Thalamus
• Gustatory cortex (includes anterior insular cortex)

Question 26

After gustatory inputs synapse on the thalamus, the axons from the thalamus then go to __

Answer 26

cortex AND to the lateral hypothalamus

-input has significant impact on appetite

Question 27

The __ seems to be strongly involved in identifying the basic taste and innate responses such as attraction to sweet tastes or aversion to bitter tastes

Answer 27

gustatory cortex

Question 28

Perception of flavor requires:

Answer 28

1) gustatory input from the gustatory cortex
2) olfactory input from the olfactory cortex (especially the piriform cortex)
3) somatosensory information from the mouth

Question 29

Neurons from the gustatory cortex, olfactory cortex, and somatosensory info from the mouth send axons to the __ cortex to produce the sensation of flavor and appreciation of food

Answer 29

lateral posterior orbitofrontal