University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

483

Pages:

1
Author:

Mariam A.

Drugs acting on dopamine system     L-Dopa: increase synaptic transmission. o Precursor to dopamine that is able to travel across the bloodbrain barrier through the AA transporters. o Clinical indications: Parkinson’s disease. Monoamine oxidase (MAO) inhibitors: increases dopamine levels in presynaptic neuron. o Selegiline is a MAO-B inhibitor. o Clinical indications: Parksinson’s disease. Dopamine D2 antagonists: o Clinical indications: schizophrenia. Cocaine: blocks reuptake of dopamine. o Extended period of pleasure. Noradrenaline  Synthesised from dopamine within vesicles.  Interacts with four receptor types in brain: o α-adrenergic and β-adrenergic. o Adrenergic receptors are metabotropic, mostly excitatory. Indolamine synthesis Serotonin  Serotonin cells are mostly located in the gut (98%) with the rest in the brain (2%). o Located in brainstem raphe nuclei and project to cortex.  Serotonin systems: o D system: originates in the dorsal raphe nucleus but does not form synapses (5-HT as a neuromodulator). o M system: originates from the median raphe nucleus and these varicosities form synapses.  There are at least 9 types of 5-HT receptors. o 5-HT1 (metabotropic): 1A, B, D, E and F. o 5-HT2 (metabotropic): 2A, B and C. o 5-HT3 (ionotropic).  Serotonin activity is terminated by reuptake.