Neurotransmitters%20and%20 psychopharmacology1
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Transcript of Neurotransmitters%20and%20 psychopharmacology1
Action Potentials (AP) release neurotransmitters (NTs) in the synapse
Body must be able to produce the chemical (endogenous)
Must be produced by the neuron When a neuron is stimulated, a chemical
is releasedChemical must act upon a receptor
to produce an effect
Major excitatory NT
Excess of glutamate can lead to hyperexcitation seizure
NMDA Receptor
AMPA and Kainate Receptor
Major inhibitory NT
Deficit in GABA may lead to lack of inhibition seizure (hyperexcitability or excitotoxicity)
GABA
Open chloride channels
Produces more profound sedative effects
Anti-convulsant
GABAA Receptor Agonist
Benzodiazepene agonist
Cerebellum has a lot of GABAa receptors
Rats have been tested using the rotorod test
Dopamine agonist leads to increase in pleasure, addiction, aggression
Dorsal vs. Ventral Pathways
D1 vs. D2 Receptors D1- Postsynaptic D2- Autoreceptor
Binds DA transporter and blocks DA reuptake, which increases synaptic DA
Produces motor activation, reward, motivational, hedonic effects
Sensitization
Causes DA transporter to release DA, blocks reuptake
Non-selective, so causes release of DA, NE, and 5HT
Used for ADHD
Found in locus coeruleus (LC)
Involved in attention and arousal, sympathetic nervous system activation
α2 vs. β receptors α2- Autoreceptor β- Blocks NE
Found in the raphe nucleus of midbrain
Deficit of 5HT can lead to depression
REM sleep deprivation can be used to treat severe depression short term
5HT1a
Predominant autoreceptor that works through GPCR
5HT2a
Predominant postsynaptic receptor that works through GPCR
LSD (5HT2a agonist) produces sensory disturbances, hedonic and panic effects, and hallucinations
Prozac, Zoloft
Many SSRIs have bad withdrawal symptoms like severe vertigo and nausea
Many antidepressants have increased suicide at onset primarily in younger population (within 2-3 weeks of drug use)
Found in the nucleus basalis and projects to the cortex
Important for cognition and muscle contraction
Acetyl CoA + Choline
Choline + Acetate
Acetylcholine + Coenzyme A
Choline transferase
Acetylcholineesterase (ACE)
Ligand gated ion channel Found in the peripheral NS
(skeletal muscle)
Nicotinic antagonist (curare) causes muscle paralysis @ NMJ
Nicotinic agonist increases muscle tension and causes tremors
Inhibitory receptor
Muscarinic agonist produces pupil constriction, diarrhea, and increase in GI activity (activates parasympathetic activity)
Muscarinic antagonist (scopolamine) used to treat diarrhea (block parasympathetic activity)
Inhibits ACh release
Toxin is very stable
Causes paralysis of the diaphragm
Have their own GPCR, meaning that there are lots of receptors
Coexist with small molecule NT
Endorphins/enkephalins
Corticotropin Release Factor (CRF)
Secreted by neurons in hypothalamus to stimulate ACTH release from anterior pituitary
Amygdala PAG hypothalamus activates sympathetic NS
CRF antagonist is anxiolytic
CRF is elevated in most depressed individuals
Endogenous cannabinoids (anandamide and 2AG)
Cannot be packaged, synthesized and released on demand
Cannabinoid receptor CB1 CB1 agonist
Orexogenic, rewarding, affects timing behavior, analgesic
Important second messenger
Viagra