Benzodiazepines – diazepam/alprazolam: bind with second site on GABA(A)
receptor – indirect agonists
Effective anxiolytics
Zolpidem and eszopiclone are related drugs
Barbiturates: bind with third binding site – indirect agonists
Alcohol and steroids bind with other sites
GABA transporters: remove GABA from the synapse
Tiagabine: GABA transporter antagonist used to increase its availability
Vigabatrin: blocks activity of GABA aminotransferase, which breaks down
GABA
Acetylcholine pathways
1. Dorsolateral pons: role in REM sleep
2. Basal forebrain: activation of cerebral cortex and facilitation of learning
3. Medial septum: control electrical rhythms of hippocampus and modulate its
functions < memory formation
ACh is composed of two precursors – choline acetyltransferase (ChAT) is required to
produce ACh from the precursors
Vesicle ACh transporter: loads and stores ACh into vesicles
Botulinum toxin prevents ACh release
Black widow spider venom: stimulates ACh release
Ionotropic ACh receptor: stimulated by nicotine – nicotinic receptor
Curare: blocks nicotinic receptors
Metabotropic ACh receptor: stimulated by muscarine – muscarinic receptor
Atropine: blocks muscarinic receptors
ACh is deactivated by acetylcholinesterase (AChE)
Neostigmine: AChE inhibitor
After being broken down, only choline is recycled
Hemicholium-3: blocks choline transporter and reduces rate of ACh production
The monoamines
Catecholamines: dopamine (DA), norepinephrine, epinephrine
Indolamine: serotonin
Ethylamine: histamine
Dopamine pathways:
(1) Nigrostriatal system: cell bodies located in substantia nigra and project axons to
the neostriatum
(2) Mesolimbic system: cell bodies located in ventral tegmental area and project
axons to several parts of the limbic system
(3) Mesocortical system: cell bodies located in ventral tegmental area and axons
project to prefrontal cortex
Degeneration of dopaminergic neurons > Parkinsons’s
Chlorpromazine: block D2 receptors, dopamine inhibition
Apomorphine: acts as an agonist and antagonist for dopamine, depending on the
dose
Dopamine transporters: responsible for removing dopamine from the synapse
Amphetamine and methamphetamine: block dopamine/norepinephrine reuptake
and cause the transporters for them to run in reverse
Ritalin/cocaine: simply block reuptake
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receptor – indirect agonists
Effective anxiolytics
Zolpidem and eszopiclone are related drugs
Barbiturates: bind with third binding site – indirect agonists
Alcohol and steroids bind with other sites
GABA transporters: remove GABA from the synapse
Tiagabine: GABA transporter antagonist used to increase its availability
Vigabatrin: blocks activity of GABA aminotransferase, which breaks down
GABA
Acetylcholine pathways
1. Dorsolateral pons: role in REM sleep
2. Basal forebrain: activation of cerebral cortex and facilitation of learning
3. Medial septum: control electrical rhythms of hippocampus and modulate its
functions < memory formation
ACh is composed of two precursors – choline acetyltransferase (ChAT) is required to
produce ACh from the precursors
Vesicle ACh transporter: loads and stores ACh into vesicles
Botulinum toxin prevents ACh release
Black widow spider venom: stimulates ACh release
Ionotropic ACh receptor: stimulated by nicotine – nicotinic receptor
Curare: blocks nicotinic receptors
Metabotropic ACh receptor: stimulated by muscarine – muscarinic receptor
Atropine: blocks muscarinic receptors
ACh is deactivated by acetylcholinesterase (AChE)
Neostigmine: AChE inhibitor
After being broken down, only choline is recycled
Hemicholium-3: blocks choline transporter and reduces rate of ACh production
The monoamines
Catecholamines: dopamine (DA), norepinephrine, epinephrine
Indolamine: serotonin
Ethylamine: histamine
Dopamine pathways:
(1) Nigrostriatal system: cell bodies located in substantia nigra and project axons to
the neostriatum
(2) Mesolimbic system: cell bodies located in ventral tegmental area and project
axons to several parts of the limbic system
(3) Mesocortical system: cell bodies located in ventral tegmental area and axons
project to prefrontal cortex
Degeneration of dopaminergic neurons > Parkinsons’s
Chlorpromazine: block D2 receptors, dopamine inhibition
Apomorphine: acts as an agonist and antagonist for dopamine, depending on the
dose
Dopamine transporters: responsible for removing dopamine from the synapse
Amphetamine and methamphetamine: block dopamine/norepinephrine reuptake
and cause the transporters for them to run in reverse
Ritalin/cocaine: simply block reuptake
19
