BIOL 4380 Lecture Notes - Lecture 11: Insular Cortex, Taste Bud, Lingual Papilla
• A taste bud consists of several types of cells, most important ones are called taste cells. They are
lodged in between basal cells. Basal cells just like in the case of the olfactory system, also serve
the purpose of regeneration. Some are stem cells and taste cells have to be regenerated every
couple of weeks
o The taste cells are epithelial cells, with apical and basal sides. On the apical sides we
have microvilli. The space between the microvilli is called taste pore. In olfactory system
these are called olfactory cilia, here they are cili but functioally they’re ery siilar.
The taste cells form synapses with gustatory afferent neurons that form respective
cranial nerve.
o There’s a differee etee the 3 types of papillae. The proportio of differet types:
the most is vallate (50%), the other 2 papillae are 25% each. Each papilla has many taste
buds (except for fungiform).
o Read about humans called supertasters: individuals who can taste things much better:
something to do with the number of taste buds.
o The arrangements of the papillae has something to do with the order of sensing
different tastants.
o Sweet/umami tastes are sensed by fungiforms, at the tip of your tongue. Salty is
experienced more uniformly, bitter in the back, and sour on the sides. Major perceptual
categories of taste.
o FMRI image: in the insular cortex which lights up, the specific regions of the insular
cortex are different for different tastes.
o ORNs are forming synapses and they are believed to be exclusively glutamatergic.
o Mehais of sesory trasdutio: taste ells do’t form glutamatergic synapses. They
make ATP, GABA or serotonin synapses.
o Depending on what taste receptor protein is expressed, a particular cell will be
responding to either of the 5 tastes.
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