The gustatory system
The Gustatory system is responsible for our sense of taste. Taste is very important to all, as it helps prepare the gut for food and it measures the nutrient composition. It is responsible for salivation, for gastric motility, releasing digestive enzymes, and insulin release.
The above picture summarizes the pathway of the taste system. Detection of taste starts from the taste papillae on the tongue (receptor cells). Taste buds are on the taste papillae. Taste cells, which are a part of the taste buds, detect chemicals within the taste buds. Interestingly, taste cells have a lifetime of about two weeks.
There are different types of tastes that the taste buds can detect. There is salt, sour, sweet, bitter, and umami (savory). All tastes can be detected over the whole surface of the tongue. When taste cells detect salt and sour-like tastes, they activate ion channels. When the taste cells detect sweet, bitter, or umami, they activate G-protein coupled receptors. When activation occurs, there is depolarization and release of neurotransmitters. The various neurotransmitters involved in taste are serotonin, ATP, and GABA.
The neurons coding for taste are coding for identity, concentration, and if the taste is good or bad. There is focal activation, or segregation, for different kinds of tastes. Different areas of the brain light up with different tastes.
The signals received on the taste buds are then sent to the solitary nucleus of the brainstem, which is where taste and visceral responses are integrated. The nucleus of the solitary tract then sends signals to the hypothalamus, amygdala, or the VPM of the thalamus. The hypothalamus and amygdala are responsible for our feelings of pleasure or aversiveness when eating something. Finally, the information reaches the cortex, which responds to combinations of visual, somatic sensory, olfactory, and gustatory stimuli.
Taste can effect your behavior: Certain tastes, like bitterness, can cause you to gag, pucker, salivate, or spit out.
There are different types of tastes that the taste buds can detect. There is salt, sour, sweet, bitter, and umami (savory). All tastes can be detected over the whole surface of the tongue. When taste cells detect salt and sour-like tastes, they activate ion channels. When the taste cells detect sweet, bitter, or umami, they activate G-protein coupled receptors. When activation occurs, there is depolarization and release of neurotransmitters. The various neurotransmitters involved in taste are serotonin, ATP, and GABA.
The neurons coding for taste are coding for identity, concentration, and if the taste is good or bad. There is focal activation, or segregation, for different kinds of tastes. Different areas of the brain light up with different tastes.
The signals received on the taste buds are then sent to the solitary nucleus of the brainstem, which is where taste and visceral responses are integrated. The nucleus of the solitary tract then sends signals to the hypothalamus, amygdala, or the VPM of the thalamus. The hypothalamus and amygdala are responsible for our feelings of pleasure or aversiveness when eating something. Finally, the information reaches the cortex, which responds to combinations of visual, somatic sensory, olfactory, and gustatory stimuli.
Taste can effect your behavior: Certain tastes, like bitterness, can cause you to gag, pucker, salivate, or spit out.
ready? quiz time!
1. Describe what types of receptors are activated for what kinds of tastes
2. Outline the pathway for the gustatory system.
3. What are the neurotransmitters involved in the gustatory system?
2. Outline the pathway for the gustatory system.
3. What are the neurotransmitters involved in the gustatory system?