What is a neurotransmitter? Chemicals secreted by neurons Stimulated action potential in adjacent...
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Transcript of What is a neurotransmitter? Chemicals secreted by neurons Stimulated action potential in adjacent...
![Page 1: What is a neurotransmitter? Chemicals secreted by neurons Stimulated action potential in adjacent neurons Two types of responses: Excitatory Inhibitory.](https://reader036.fdocuments.net/reader036/viewer/2022081502/5a4d1ba57f8b9ab0599c8b65/html5/thumbnails/1.jpg)
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What is a neurotransmitter?Chemicals secreted by neurons
Stimulated action potential in adjacent neurons
Two types of responses:ExcitatoryInhibitory
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Types of ResponsesExcitatory:
Opens sodium gatesStarts a nerve
impulseInhibitory
Makes neuron more negative on inside Raises Threshold
Requires more stimulus to start a nerve impulse
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SummationEffect produced by the accumulation of
neurotransmitters from two or more neurons
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EXAMPLESNeurotransmitter
Excitatory or Inhibitory
Effect
Acetylcholine Both excitatory and inhibitory
•Involved with somatic & parasympathetic nervous systems•Stimulates skeletal muscles•Inhibits cardiac muscles
Norepinephrine (noradrealine)
Excitatory •Involved with sympathetic nervous system
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Neurotransmitter
Excitatory or Inhibitory
Effect
Glutamate Excitatory •Cerebral cortex (brain) excitatory transmissions•75% of all transmissions
GABA (Gamma aminobutyric acid)
Inhibitory •Cerebral cortex inhibitory transmissions
Dopamine Excitatory •Elevates mood•Controls skeletal muscles
Seratonin Inhibitory •Involved in alertness , sleepiness, mood, thermoregulation
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DisordersAlzheimer’s Disease
Low acetylcholine
Parkinson’s DiseaseLow dopamine
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Drugs….Which are good? Which are bad?
Prescription drugsMade to alter neurotransmitter release
Addictive drugsInterfere with neurotransmittersProduce feeling of pleasure
Release dopamine
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Prescription DrugsValium
Increases GABAResult: alleviate anxiety
ProzacEnhances serotoninResult: antidepressant
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Drug and Poison OverviewMuscle paralysis
E.g. Nerve gas, botulin toxin, some insecticides
Result: disrupts acetylcholine
StimulantsMimics norepinephrineResult: alertness,
excitement
DepressantsBlock
norepinephrine formation
Result: slows body activity, depression
HallucinogensInterferes with
serotonin
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MethamphetamineEnters synaptic vessiclesCauses dopamine releaseBlocks dopamine from reentering synaptic
knobResult:
Increased pleasure
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CocaineEnters synapseBlocks dopamine from reentering synaptic
knobResult:
Increased pleasure
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NictoineBinds to receptor
on presynaptic neuron
Causes more dopamine to be released