Download Widely Found and Studied Neurotransmitters

Widely Found and Studied
Neurotransmitters
 Glutamate – has excitatory functions
 4 Ascending activating systems are very
important
 Cholinergic System uses acetylcholine
 Adrenergic system uses noradrenalin
 Dopaminergic system (actually 2 systems) use
dopamine
 Serotonergic system uses 5-Ht or serotonin
 GABA or gamma-amino butyric acid – has
inhibitory functions
Acetylcholine
 Activate two types of receptors:
 Nicotinic receptors– also stimulated by
nicotine and inactivated or blocked by curare
 Muscarinic receptors– stimulated by
muscurine and blocked by atropine and
scopolamine – use second messenger
Monoamines
 Dopamine – up to 6 types of receptors
 Tyrosine forms L-dopa
 L-dopa synthesized to form dopamine
 Norepinephrine – created by synthesis of
dopamine
 Epinephrine – created from Norepinephrine
 Serotonin (5-Ht) – synthesized from tryptophan
Peptides
 Many types of neuropeptides; two have
been extensively studied
 Sustance P – constriction and dilation of
blood vessels
 Opioid types –
 Endorphins
 enkephalins
How Drugs Work in the
Brain
 They work at the level of the synapse
 Agonists
 Antagonists
Possible Drug Actions at
the Synapse
 increase or decrease the synthesis or production of
neurotransmitters
 increase or decrease the ability of the cell to store the chemical in
vesicles
 increase or decrease the amount of transmitter released by
vesicles into the synapse
 it can increase the number and length of time a receptor is open
by increasing or decreasing the production of enzymes that break
down the neurotransmitter
 block or enhance the reuptake and reuse of the neurotransmitter
 Altering the actions of second messegers