Gustation: Taste Receptors Cells Flashcards
What is the Apical end of a taste receptor cell?
The samll membrane region that is the chemically sensitive part of a taste receptor cell.
What is microvilli?
The thin extensions of the apical ens that project into the taste pore.
What is the taste pore?
A small opening on the surface of the tongue where the taste cell is exposed to the contents of the mouth
Are taste receptor cells neurons?
Taste receptor cells are not neurons according to standard histological criteria.
Why might taste receptor cells be mistaken for neurons?
Because taste receptor cells do form synapses with the endings of the gustatory afferent axons near the bottom of the taste bud.
They also make both electrical and chemical synapses onto some of the basal cells; some basal cells synapse onto the sensory axons and these may form a simple information processing circuit of growth, death, and regeneration; the lifespan of one taste cell is about 2 weeks. This process depends on an influence of the sensory nerve, because if the nerve is cut, the taste buds will degenerate.
What is receptor potential in taste receptor cells?
When an appropriate chemical activates a taste receptor cell, it’s membrane potential changes —-> usually depolarizing
What does depolarization of a taste receptor cell membrane cause?
cause voltage-gated calcium channels to open; Ca2+ enters the cytoplasm, triggering the release of transmitter molecules
*this is basic synaptic transmission from taste cells to sensory axon
What determines what transmitter is released from a taste cell?
dependant on the taste receptor cell type.
What neurotransmitters do sour and salty taste cells release?
serotonin, released onton gustatory axons
What neurotransmitters do sweet, bitter, and umami taste cells release?
ATP (adenosine triphosphate)
Do taste receptor’s transmitter excite or inhibit the postsynaptic sensory axon?
Excites; the postsynaptic sensory asnons and casues it to fire action potentials, which communicate the taste signal into the brain stem.
Where do excited postsynaptic sensory axons communicate the taste signal?
into the brain stem
What are the other transmitters taste cells MAY use, but are functions are unknown?
Acetylcholine, GABA, and glutamate
