10. Chemical signalling Flashcards
What do neuromodulators do? (Signalling B&B)
- Affect the response properties of the neurone
- Do not carry a primary information
What are the 4 main types of chemical signals? (Signalling B&B)
- Dopamine
- Noradrenaline
- Serotonin
- Acetylcholine
What are the three systems associated with dopamine? (Signalling B&B)
- Nigrostriatal system
- Mesolimbic system
- Mesocortical system
What is the role of the nigrostriatal system for dopamine and what would happen if it was impaired? (Signalling B&B)
- Role in movement
- Parkingson’s/Huntington’s
What is the role of the mesolimbic system for dopamine and what would happen if it was impaired? (Signalling B&B)
- Role in reinforcement
- Addiction
What is the role of the mesocortical system for dopamine and what would happen if it was impaired? (Signalling B&B)
- Role in functions e.g. working memory
- Schizophrenia
What three ways can tyrosine hydroxylase be regulated with dopamine? (Signalling B&B)
- Feedback inhibition (down regulation)
- Presynaptic activity (up regulation)
- Prolonged activity (up regulation)
How is dopamine released? (Signalling B&B)
- Depolarisation of presynaptic membrane
- Influx of Ca2+ through gated Ca2+ channels
- Ca2+ dependent vesicles dock
- Dopamine released
What system aids noradrenaline? (Signalling B&B)
The noradrenergic system
What does the noradrenergic system act on? (Signalling B&B)
Projections from the locus coeruleus throughout the brain
If the noradrenergic system is impaired, what are the effects? (Signalling B&B)
Anxiety and depression
What system aids serotonin? (Signalling B&B)
The serotonergic system
What is the process of serotonin synthesis? (Signalling B&B)
- Storage onto vesicles
- Released through Ca2+ dependent excitosis
- Reuptake through serotonin transporters
What drugs affect dopamine levels? (Signalling B&B)
- Reserpine
- L-DOPA
What drugs affect serotonin levels? (Signalling B&B)
- Fluoxetine
- Fenfluramine
- MDMA
