7. Phys of Taste and Olfaction

Question 1

What tastants trigger the release of serotonin?

Answer 1

Sour and salty

Question 2

What tastants trigger the release of ATP?

Answer 2

Sweet, umami, and bitter

(SUB sandwiches give you energy)

Question 3

What channel involved in tast evoked secretion of ATP allows influx of sodium?

Answer 3

TRPM5

Question 4

What channel involved in taste evoked secretion of ATP is involved in ATP release?

Answer 4

Panx1

Question 5

What GPCR is involved with the umami flavor?

Answer 5

mGluR4 (glutamate receptor)

Question 6

Which tastant binds its GPCR with very high binding affinity?

Answer 6

Bitter (avoid poison)

Question 7

Where are the cell bodies of afferent neurons coming from the anterior tongue located?

Answer 7

Geniculate ganglion

Question 8

Where are the cell bodies of afferent neurons from the posterior tongue located?

Answer 8

Petrosal ganglion

Question 9

Where are the cell bodies of afferent neurons from the epiglottis located?

Answer 9

Nodose ganglion

Question 10

Where do the afferent neurons (1st order) coming from the taste buds terminate?

Answer 10

Nucleus Tractus Solitarius (gustatory area)

Question 11

In the ascending taste pathway, where do the 2nd order sensory neuron cell bodies arise? Where do they terminate?

Answer 11

Arise from nucleus tractus solitarius

Terminate in VPM nucleus of thalamus

Question 12

Where do the 3rd order neurons of the ascending taste pathway arise? Where do they terminate?

Answer 12

Arise from VPM and travel through posterior limb of IC

Terminate in postcentral gyrus, frontal operculum, insular cortex

Question 13

What role does the orbitofrontal cortex have in the taste pathway?

Answer 13

Interpretation of taste, olfaction, and visual cues regarding food

Appreciation of flavor, food reward, control of feeding

Question 14

What are the cortical areas making up the gustatory cortex?

Answer 14

Postcentral gyrus

Frontal operculum

Insula

Question 15

What is the channel activated in the olfactory signaling pathway?

Answer 15

Cyclic Nucleotide-gated channels (CNGC)

Question 16

What is activated by the G-olf GPCR pathway?

Answer 16

Adenylyl Cyclase III => activates CNGC

Question 17

What are the 2 main ways that adaptation to odorant stimulation occurs?

Answer 17

1. Sensitivity of CNGC to cAMP decreases => decreased cation influx => decreased depole
2. Inactivation by receptor phosphorylation

Question 18

What cells of the olfactory pathway release GABA?

Answer 18

Periglomerular cells

Granular cells

Question 19

What structure of the olfactory cortex transmits information to the thalamus? What purpose does this serve?

Answer 19

Piriform cortex

Thalamus sends info to medial orbitofrontal cortex => integration of taste, sight, and smell, appreciation of flavor of food

Question 20

What part of the olfactory cortex is involved with emotional learning and olfactory fear conditioning?

Answer 20

Anterior cortical amygdaloid nucleus

Question 21

What part of the olfactory cortex is involved in integration of the emotional aspect elicited by odor?

Answer 21

Periamygdaloid cortex

Question 22

What 2 structures communicate to integrate olfactory information in memory formation and recall?

Answer 22

Entorhinal cortex => hippocampus

Question 23

Where does adult neurogenesis occur?

Answer 23

Olfactory bulb

Dentate gyrus of the hippocampus