PSYC 110 Lecture Notes - Lecture 16: Fluoxetine, Methylphenidate, Tegmentum
27 Jun 2018
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Psychoactive drugs: change the way the brain works by altering the way neurons fire
Change behavior, movement, perception and specific cognitive functions
COCAINE: drug of rich people
David Bowie- 1974- he was on cocaine
He was fidgeting a lot, he sniffed a lot because cocaine irritates the nasal mucosa
Action potential is a change in the voltage of a neuron.
Travels the length of the axon, arrives in the terminal buttons and releases neurotransmitters in the
synapse.
Pre synaptic neuron releases the neurotransmitters which activate the receptors on the post synaptic
neuron.
Neurotransmitters are chemical molecules produced by neurons.
Sends chemical communication between neurons
Released in synapse in response to depolarization
Can turn on a neuron(excitation) and can turn it off( inhibition)
Resting potential = -70 mV, closer it gets to that charge more likely it is to fire
Excitation or inhibition depends on the combination of neurotransmitter and receptor
First figure- excitatory- acetylcholine binds with the receptors and gets closer to the threshold potential.
Second figure- inhibitory- acetylcholine pushes membrane potential away from zero, ex: positive ions
are moving out of the cell
Neurotransmitter life cycle
1. Created inside the pre synaptic neuron
2. Packaged up into synaptic vesicles. Vesicles are made up of the same stuff as a cell
membrane
3. Released: When it reaches the synapse it bind to the synaptic edge and spill the
contents into the synapse
4. Binding: randomly move and bind to postsynaptic receptors
5. Cleared from the synapse
Reuptake Inhibitors:
Cocaine affects at least one neurotransmitters in one of the above steps. All psychoactive drugs affect
one or more of the steps. Cocaine affects the last step.
Clearing neurotransmitters work by:
1. Reuptake pumps - suck up the neurotransmitter back into the axon terminal where it
can be recycled for usage in the next round (vacuum)
2. Enzymes breakdown the neurotransmitters into smaller components that arent enough
to activate the neurotransmitter receptors (hammer)
3. Passively flow out of the synapse - running man
Cocaine affects the dopamine reuptake pumps, its like clogging a vacuum. Hence the concentration of
dopamine in synapse rises. Thus cocaine acts as dopamine reuptake inhibitor. Rate of dopamine activity
on post synaptic neuron rises. Eventually there will be a desensitization of dopamine on post synaptic
neuron and this explains addiction. -> high levels of dopamine increases the feeling of pleasure and thus,
promotes addiction towards the drug
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Psychoactive drugs: change the way the brain works by altering the way neurons fire. Change behavior, movement, perception and specific cognitive functions. He was fidgeting a lot, he sniffed a lot because cocaine irritates the nasal mucosa. Action potential is a change in the voltage of a neuron. Travels the length of the axon, arrives in the terminal buttons and releases neurotransmitters in the synapse. Pre synaptic neuron releases the neurotransmitters which activate the receptors on the post synaptic neuron. Can turn on a neuron(excitation) and can turn it off( inhibition) Resting potential = -70 mv, closer it gets to that charge more likely it is to fire. Excitation or inhibition depends on the combination of neurotransmitter and receptor. First figure- excitatory- acetylcholine binds with the receptors and gets closer to the threshold potential. Second figure- inhibitory- acetylcholine pushes membrane potential away from zero, ex: positive ions are moving out of the cell.
