Download Molecular Neurobiology Lecture 8: Calcium Channels, Ion Pumps, and Action Potentials and more Study notes Neurobiology in PDF only on Docsity! MCDB 4777/5777 Molecular Neurobiology Lecture 8 Calcium channels, ion pumps, action potential overview and transition to synapses 3.12 Action potential conduction requires both active and passive current flow. (Part 1)
GIRK- how parasympathetic innervation slows your heart
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4.6 Topology of principal subunits of voltage-gated Na+, Ca2+, K+, and Cl– channels. (Part 3) 45 Diverse properties of K* channels. (Part 1)
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Pore loop sequence variability and selectivity The amino-acid sequences from a range of ion channels (centre) show remarkable similarity in the region of the selectivity filter. Red highlights show the conserved glycines in the 'signature' sequence TVGYG found in the potassium ion channel KcsA. Yellow highlights show amino acids that are chemically similar. As the filter sequence becomes less conserved, the channels lose their selectivity for K+ over Na+ and become more permeable to Ca2+. The structure of the nonselective cation channel NaK from Bacillus cereus has been solved by Jiang and colleagues5. Comparison of the selectivity filters of NaK and KcsA (left) provides structural clues to sodium-ion permeability. Membrane biology:ﾊ Permutations of permeabilityWilliam N. ZagottaNature 440, 427-429 (23 March 2006) Coordination of potassium ions by the selectivty filter • Top panel: A backbone diagram of the ion-selectivity filter of KcsA. P1ﾐP5 correspond to five K+- binding sites that are numbered from the outside (top). The P0 site mentioned in the main text is not shown. Each site is formed by eight oxygen atoms (red) that surround each K+ ion (green) as it passes through the channel. The P1ﾐP4 sites are formed by oxygens contributed by the channel protein. The P5 site is formed by eight immobilized water molecules. Potassium channel structuresSenyon ChoeNature Reviews Neuroscience 3, 115-121 (February 2002).
4.4 Types of voltage-gated ion channels. (Part 1)
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NEUROSCIENCE, Third Edition, Figure 4.4 (Part 1) © 2004 Sinauer Associates, Inc.
4.10 Examples of ion transporters found in cell membranes. (Part 1) 4.10 Examples of ion transporters found in cell membranes. (Part 2) 4.11 Ionic movements due to the Na+/K+ pump. (Part 2) 4.13 Molecular structure of the Na*/K* pump. (Part 2)
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NEUROSCIENCE, Third Edition, Figure 4.13 (Part 2) © 2004 Sinauer Associates, Inc,
3.12 Action potential conduction requires both active and passive current flow. (Part 1) 5.1 Electrical and chemical synapses differ fundamentally in their transmission mechanisms.
