80 likes | 208 Views
Transmitter Release I: Welcome back from spring break!. 26 March 2012. Questions?. Housekeeping. Mid-term Evaluations (mine) Exam II: Mean = 126/150 (84%) Good job!. Criteria for new Neurotransmitters. The chemical must be produced and found within a neuron
E N D
Transmitter Release I: Welcome back from spring break! 26 March 2012
Housekeeping Mid-term Evaluations (mine) Exam II: Mean = 126/150 (84%) Good job!
Criteria for new Neurotransmitters • The chemical must be produced and found within a neuron • When a neuron is stimulated (depolarized), a neuron must releasethe chemical in a Ca2+-dependent fashion • When a chemical is released, it must act on a post-synaptic receptor present on the postsynaptic membrane • The chemical, when released, must cause a biological effect • After a chemical is released, it must be inactivated • If the chemical is applied to the post-synaptic membrane, it should have the same effect as when it is released by a neuron
Glutamate (Glu; Glutamic Acid) • Amino acid neurotransmitter • Most important excitatory neurotransmitter in the brain (not always excitatory) • Produced in neurons by metabolism • No effective way to block synthesis without disrupting other cell activities
Glutamate Receptors • Four major kinds: • AMPA • Kainate • NMDA • Metabotropic glutamate receptor (mGluR) • Ionotropic
Glutamate Receptors • AMPA • Stimulated by AMPA (a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) • Most common Glu receptor • Ionotropic; Na+ channel • Kainate • Stimulated by Kainic acid • Ionotropic; Na+ channel
Glutamate Receptors • NMDA • Activated by NMDA (n-methyl-d-aspartate) • Ionotropic; permeable to Na+ and Ca2+ • Includes six different binding sites • Four on extracellular surface • Two deep within ion channel