Serotonin Flashcards
What is serotonin involved in?
Aggression, anxiety, patience, sleep, hunger, vasocontriction, vasodilation, GI motility, etc.
Where is serotonin?
Everywhere
How many receptors are there for serotonin?
There are 14 receptors with 7 families
How is serotonin transmitted?
Either one to one or synapses onto different cellular locations
What can 5-HT be found in?
Plants and animals
When and how was serotonin isolated?
1930s and 40a to induce gut contractions
How much of serotonin is in intestine?
90%
Serotonin absorption
- has to cross blood brain barrier
- active process
- limited capacity
What does para-chlorophenlylalanine do ?
block tryptophan hydroxylase with para-chlorophenylalanine - reducing the levels of serotonin
What does reserpine do?
Depletes serotonin by targetting VMAT2
What do SSRIs do?
Block the 5-HT transporter and then causes an increase in serotonin
What does parachloroamphetamine or MDMA do?
cause the release of serotonin from the vesicles
Whats another way of manipulating serotonin?
Agonists and antagonists
How many of the 5-HT families are GPCR?
All but one
With the 5-HT1a receptor what is the g protein?
Gi/o
What does the action on the 5-HT1a cause?
reduction in cAMP and therefore cAMP dependant kinase, there is an increase in K+
What if you have more 5-HT1a receptors?
More likely to experience depression and when given fluxetine then it wont help as there isnt as much serotonin in the cleft
What G protein is used with the 5-HT2a receptor ?
Gq/11
What will the coupled receptor for 5-HT2a activate ?
Phospholipase C
What does phospholipase C do?
Cleave PIP2 into IP3 and DAG
What does IP3 do?
Release calcium from internal stores
What do calcium and DAG do together?
Activate protein kinase C
What does the overall effect of the 5-HT2a receptor have?
Depolarisarion of the neuron causing an excitatory effect
Which condition is the 5-HT2a receptor linked to?
Schizophrenia
