Phys of Taste and Olfaction Flashcards
What tastants trigger the release of serotonin?
Sour and salty
What tastants trigger the release of ATP?
Sweet, umami, and bitter
(SUB sandwiches give you energy)
What channel involved in tast evoked secretion of ATP allows influx of sodium?
TRPM5
What channel involved in taste evoked secretion of ATP is involved in ATP release?
Panx1
What GPCR is involved with the umami flavor?
mGluR4 (glutamate receptor)
Which tastant binds its GPCR with very high binding affinity?
Bitter (avoid poison)
Where are the cell bodies of afferent neurons coming from the anterior tongue located?
Geniculate ganglion
Where are the cell bodies of afferent neurons from the posterior tongue located?
Petrosal ganglion
Where are the cell bodies of afferent neurons from the epiglottis located?
Nodose ganglion
Where do the afferent neurons (1st order) coming from the taste buds terminate?
Nucleus Tractus Solitarius (gustatory area)
In the ascending taste pathway, where do the 2nd order sensory neuron cell bodies arise? Where do they terminate?
Arise from nucleus tractus solitarius
Terminate in VPM nucleus of thalamus
Where do the 3rd order neurons of the ascending taste pathway arise? Where do they terminate?
Arise from VPM and travel through posterior limb of IC
Terminate in postcentral gyrus, frontal operculum, insular cortex
What role does the orbitofrontal cortex have in the taste pathway?
Interpretation of taste, olfaction, and visual cues regarding food
Appreciation of flavor, food reward, control of feeding
What are the cortical areas making up the gustatory cortex?
Postcentral gyrus
Frontal operculum
Insula
What is the channel activated in the olfactory signaling pathway?
Cyclic Nucleotide-gated channels (CNGC)
What is activated by the G-olf GPCR pathway?
Adenylyl Cyclase III => activates CNGC
What are the 2 main ways that adaptation to odorant stimulation occurs?
- Sensitivity of CNGC to cAMP decreases => decreased cation influx => decreased depole
- Inactivation by receptor phosphorylation
What cells of the olfactory pathway release GABA?
Periglomerular cells
Granular cells
What structure of the olfactory cortex transmits information to the thalamus? What purpose does this serve?
Piriform cortex
Thalamus sends info to medial orbitofrontal cortex => integration of taste, sight, and smell, appreciation of flavor of food
What part of the olfactory cortex is involved with emotional learning and olfactory fear conditioning?
Anterior cortical amygdaloid nucleus
What part of the olfactory cortex is involved in integration of the emotional aspect elicited by odor?
Periamygdaloid cortex
What 2 structures communicate to integrate olfactory information in memory formation and recall?
Entorhinal cortex => hippocampus
Where does adult neurogenesis occur?
Olfactory bulb
Dentate gyrus of the hippocampus
