PSYC 4035 : Psyc4035 Test 2
PSYCHOHARMACOLOGY 5/26/2014 4:42:00 PM
Psychopharmacology- the scientific study of the effects drugs have on mood, sensation, thinking, and behavior;
study of the use of medications in treating mental disorders.
Neurons are signals to cells
• They have long extensions off cell body called axon
• Shorter ones called dendrite
Where the axon ends is called synapse
• point of contact between two neurons; where they communicate
• Where the drug produces its effects
Neurons communicate by releasing chemical into semantic clef, called a neurotransmitter
Chemical Synapse
Synapse– specialized zone of contact between two neurons where interneuronal communication takes place
Presynaptic neuron– sending neuron
Postsynaptic neuron– receiving neuron; receptors;
Synapse clef- the space between neurons at a nerve synapse across which a nerve impulse is transmitted by a
neurotransmitter
Parts of a synapse: presynaptic element, post synaptic element, synaptic cleft
Synaptic vesicle- stores various neurotransmitters that are released at the synapse
neuro transmitters are sythesized in neurons, once that happens they are put in storage (synamptic veicle); the dots inside are
molecules of neutransmitters
Presynaptic nerves release neurotransmitters by synaptic vesicle exocytosis.
Why does neuro transmitter have to packaged (synaptic vesicle)?
In the fluid outside vehicle there are enzymes that are capable of breaking the neurotransmitter down, causing no
function; The synaptic vesicle keeps this from happening
• Necessary for it to be released
• Exocytosis- generic term for any instant where a cell dumps the contact of a storage sack to the
exterior
o Action potential triggers exocytosis
o When an action potential depolarizes the plasma membrane, channels open, and Ca2+ flows into the
nerve terminal to trigger the exocytosis of synaptic vesicles, thereby releasing their neurotransmitters
into the synaptic cleft.
• Post symmetric neurons are receptors
o When receptor is activated, it changes it shape that opens a hole in wall of the cell, and ions
go in.
• Auto receptors- The cell that releases the transmitter, it has receptors on it that can…
o Presynaptic prohibition- stimulation of auto receptor, inhibits the pre synaptic neuron from
inhibiting neurotransmitter
After a transmitter is released, there are mechanisms that remove it from synaptic clef. This removal is call
inactivation. Two ways for inactivation:
• Insamanic break down (catabolism)- Catabolism is the set of metabolic pathways that breaks down
molecules into smaller units to release energy
o What is being represented by blue horse shoe; an enzyme has affinity for molecules, and
when that happens the neurotransmitters stops the process
• Reuptake- the presynaptic neuron is drawing the neurotransmitter back; reabsorption of a
neurotransmitter by a neurotransmitter transporter of a pre-synaptic neuron after it has performed
its function
o Transporters require energy (active transport)
Drug Mechanisms of Action- what a drug does at a cellular/molecular level to change the biology of cell
Neurotransmitters are synthesized in the neuron, what is being shown
• Drugs can either block the synthesis or speed it up
• Speed it up by providing more precursor; you block it by drug binding to enzyme and prevents it from working
• There are some drugs that block the storage of neurotransmitters; if you didn't store neurotransmitters in
vehicles…it would be broken down by enzymes
Some substance called precursor is turned into neurotransmitter
*drug can alter any of these*
some drugs work with exocytosis to speed it up or slow it down
drugs can bind to receptors and either bind or activate actvity
receptors are not here for drugs
inactivation- degradation/reuptake
a drug that prevents__is going to cause an increase in metabolism of neurotransmitters. You get an over stimulation.
Membrane transporter
Small group of neurotransmitters that are responsible for drugs
Receptor-intrinsic protein is a ion channel (allows some charged particles to move from one side of membrane to
the other)
• Yellow circle is neurotransmitter molecule. When two neurotransmitters bind outside of cell, the blue
dots come into the cell
• Neurotransmitter bind to receptors, that activates another protein, when a activated it travels across
the membrane and it activates some other protein.
Neurotransmitters and their pharmacology
The first neurotransmitter discovered was Acetylcholine .Around 1920. Scientist had been arguing for decades
about brain cell communicating chemically/electrically
The monoamine neurotransmitters aka biogenic amines
• Monoamines: dopamine, epinephrine, and norepinephrine.
• Monoamines: most common group of substances
o Catecholamines=adrenaline
▪ created within the body from amino acids such as phenylalanine and tyrosin
Document Summary
Psychopharmacology- the scientific study of the effects drugs have on mood, sensation, thinking, and behavior; study of the use of medications in treating mental disorders. They have long extensions off cell body called axon. Where the axon ends is called synapse point of contact between two neurons; where they communicate: where the drug produces its effects. Neurons communicate by releasing chemical into semantic clef, called a neurotransmitter. Synapse specialized zone of contact between two neurons where interneuronal communication takes place. Synapse clef- the space between neurons at a nerve synapse across which a nerve impulse is transmitted by a neurotransmitter. Parts of a synapse: presynaptic element, post synaptic element, synaptic cleft. Synaptic vesicle- stores various neurotransmitters that are released at the synapse neuro transmitters are sythesized in neurons, once that happens they are put in storage (synamptic veicle); the dots inside are molecules of neutransmitters. Presynaptic nerves release neurotransmitters by synaptic vesicle exocytosis.
