LECTURE 18 3-6-15-Pg. 147 Figure 5-6: Look at this figure for a better understanding- not an essay question on test-Types of Synapses*Axomuscular:Axon synapses with a muscle end plate (acetylcholine)*Axodendritic:Axon terminal and dendritesDendrodendritic:Dendrites send messages to other dendritesAxondendritic:Axon terminal of one neuron synapses on the dendritic spine of another (same as axodendritic)Axonextracellular:Axon terminal with no specific target. Secretes transmitter into extracellular fluidAxosomatic:Axon terminal ends on cell bodyAxosynaptic:Axon terminal ends on another axon terminalAxoaxonic:Axon terminal ends on another axonAxosecretory:Axon terminal ends on a blood vessel and secretes its transmitter directly into the blood-Types of MessagesExcitatoryType I SynapseTypically furthest from axon hillockInhibitoryType II SynapseTypically furthest from axon hillockCan act as a defense against excitatory signalsLocationsInhibiting an action potential-Identifying NeurotransmittersWe know 60, we estimate there are at least 100-120 total1000s of chemicals in the nervous systemIdentification:1. The chemical must be synthesized in the neuron or otherwise present in it (build it, store it, make it exist)2. When the neuron is active, the chemical must be released and produce response in some target3. The same response must be obtained when the chemical is experimentally placed on the target4. A mechanism must exist for removing the chemical from its site of action after its work is done-*One neurotransmitter can house many different neurotransmitters-Classes of Neurotransmitters1. Small-Molecule TransmittersQuick actingStored in terminal buttonsDerived from the digestive tractInfluenced by dietCan be influenced by drugsBind to ion channelsAcetylcholine (Ach)Histamine (H)Dopamine (DA)Norepinephrine (NE)Serotonin (5-HT)Glutamate (Glu)2. Peptide Transmitters3. Transmitter gasesPSYC 260 1st EditionLecture 18Outline of Last LectureI. Steps of Neurotransmission Outline of Current LectureI. Types of SynapsesII. Types of MessagesIII. Identifying NeurotransmittersIV. Classes of NeurotransmittersCurrent Lecture LECTURE 18 3-6-15 -Pg. 147 Figure 5-6: Look at this figure for a better understanding- not an essay question on test -Types of Synapses- *Axomuscular:o Axon synapses with a muscle end plate (acetylcholine)- *Axodendritic:o Axon terminal and dendrites- Dendrodendritic:o Dendrites send messages to other dendrites - Axondendritic:o Axon terminal of one neuron synapses on the dendritic spine of another (same as axodendritic)- Axonextracellular:o Axon terminal with no specific target. Secretes transmitter into extracellular fluid- Axosomatic:o Axon terminal ends on cell body- Axosynaptic:o Axon terminal ends on another axon terminal- Axoaxonic:o Axon terminal ends on another axon- Axosecretory:o Axon terminal ends on a blood vessel and secretes its transmitter directly into the blood -Types of Messages- Excitatoryo Type I Synapseo Typically furthest from axon hillock- Inhibitoryo Type II Synapseo Typically furthest from axon hillocko Can act as a defense against excitatory signals- Locationso Inhibiting an action potential -Identifying Neurotransmitters- We know 60, we estimate there are at least 100-120 total- 1000s of chemicals in the nervous system- Identification:o 1. The chemical must be synthesized in the neuron or otherwise present in it(build it, store it, make it exist)o 2. When the neuron is active, the chemical must be released and produce response in some target o 3. The same response must be obtained when the chemical is experimentally placed on the targeto 4. A mechanism must exist for removing the chemical from its site of action after its work is done -*One neurotransmitter can house many different neurotransmitters -Classes of Neurotransmitters- 1. Small-Molecule Transmitterso Quick actingo Stored in terminal buttonso Derived from the digestive tract Influenced by diet Can be influenced by drugso Bind to ion channels Acetylcholine (Ach) Histamine (H) Dopamine (DA) Norepinephrine (NE) Serotonin (5-HT) Glutamate (Glu)- 2. Peptide Transmitters- 3. Transmitter
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