PSYC 375 Chapter Notes - Chapter 5: Coenzyme A, Choline Acetyltransferase, Serotonergic

• School: University of Calgary
• Department: Psychology
• Course: PSYC 375
• Professor: Simon Spanswick

Document Summary

Loewi was the first to isolate chemical messengers with his frog heart experiment. Further experimentation with frog hearts led to the discovery of epinephrine, and specifically norepinephrine, which accelerates heart rate. Chemical messengers released by a neuron onto a target to cause an excitatory or inhibitory effect are neurotransmitters. When neurotransmitters are free floating in the body, they are hormones, and because they travel to more distant targets, their effect is slower to happen. The electron microscope led to the examination of the synaptic structure. The use of the electron microscope revealed the synaptic vesicles, which contain neurotransmitters, as well as the synaptic cleft, which separates the dendrites from the axon terminal. The presynaptic membrane forms the axon terminal. The postsynaptic membrane forms the dendritic spine. In the axon terminal are specialized structures that include the mitochondria, which serve as energy suppliers; the storage granules, large compartments that hold several synaptic vesicles; and microtubules, which transport substances to the terminal.