logging in or signing up Ch 4: Synaptic Transmission wessellr Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 843 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: December 05, 2008 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Slide 1: How Neurons Send and Receive Signals Chapter 4 Neural Conduction and Synaptic Transmission Synaptic Transmission of Chemi-cal Signals: Structure of Synapses : Synaptic Transmission of Chemi-cal Signals: Structure of Synapses Most common Axodendritic – axons on dendrites Axosomatic – axons on cell bodies Dendrodendritic – capable of transmission in either direction Axoaxonic – may be involved in presynaptic inhibition Synthesis, Packaging, and Transport of Neurotransmitter Molecules : Synthesis, Packaging, and Transport of Neurotransmitter Molecules Neurotransmitter molecules Small Synthesized in the terminal button and packaged in synaptic vesicles Large Assembled in the cell body, packaged in vesicles, and then transported to the axon terminal Release of Neurotransmitter (NT) Molecules : Release of Neurotransmitter (NT) Molecules Exocytosis – the process of NT release The arrival of an AP at the terminal opens voltage-activated Ca2+ channels The entry of Ca2+ causes vesicles to fuse with the terminal membrane and release their contents Activation of Receptors by NT Molecules : Activation of Receptors by NT Molecules Released NT molecules produce signals in postsynaptic neurons by binding to receptors Receptors are specific for a given NT Ligand – a molecule that binds to another A NT is a ligand of its receptor Receptors : Receptors There are multiple receptor types for a given NT Ionotropic receptors – associated with ligand-activated ion channels Metabotropic receptors – associated with signal proteins and G proteins Ionotropic Receptors : Ionotropic Receptors NT binds and an associated ion channel opens or closes, causing a PSP If Na+ channels are opened, for example, an EPSP occurs If K+ channels are opened, for example, an IPSP occurs Metabotropic Receptors : Metabotropic Receptors Effects are slower, longer-lasting, more diffuse, and more varied (1) NT 1st messenger binds. (2) G protein subunit breaks away. (3) Ion channel opened/closed OR a 2nd messenger is synthesized. (3) 2nd messengers may have a wide variety of effects. Slide 9: Ionotropic and Metabotropic Receptors Reuptake, Enzymatic Degradation, and Recycling : Reuptake, Enzymatic Degradation, and Recycling As long as NT is in the synapse, it is active – activity must somehow be turned off Reuptake – scoop up and recycle NT Enzymatic degradation – a NT is broken down by enzymes You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Ch 4: Synaptic Transmission wessellr Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 843 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: December 05, 2008 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Slide 1: How Neurons Send and Receive Signals Chapter 4 Neural Conduction and Synaptic Transmission Synaptic Transmission of Chemi-cal Signals: Structure of Synapses : Synaptic Transmission of Chemi-cal Signals: Structure of Synapses Most common Axodendritic – axons on dendrites Axosomatic – axons on cell bodies Dendrodendritic – capable of transmission in either direction Axoaxonic – may be involved in presynaptic inhibition Synthesis, Packaging, and Transport of Neurotransmitter Molecules : Synthesis, Packaging, and Transport of Neurotransmitter Molecules Neurotransmitter molecules Small Synthesized in the terminal button and packaged in synaptic vesicles Large Assembled in the cell body, packaged in vesicles, and then transported to the axon terminal Release of Neurotransmitter (NT) Molecules : Release of Neurotransmitter (NT) Molecules Exocytosis – the process of NT release The arrival of an AP at the terminal opens voltage-activated Ca2+ channels The entry of Ca2+ causes vesicles to fuse with the terminal membrane and release their contents Activation of Receptors by NT Molecules : Activation of Receptors by NT Molecules Released NT molecules produce signals in postsynaptic neurons by binding to receptors Receptors are specific for a given NT Ligand – a molecule that binds to another A NT is a ligand of its receptor Receptors : Receptors There are multiple receptor types for a given NT Ionotropic receptors – associated with ligand-activated ion channels Metabotropic receptors – associated with signal proteins and G proteins Ionotropic Receptors : Ionotropic Receptors NT binds and an associated ion channel opens or closes, causing a PSP If Na+ channels are opened, for example, an EPSP occurs If K+ channels are opened, for example, an IPSP occurs Metabotropic Receptors : Metabotropic Receptors Effects are slower, longer-lasting, more diffuse, and more varied (1) NT 1st messenger binds. (2) G protein subunit breaks away. (3) Ion channel opened/closed OR a 2nd messenger is synthesized. (3) 2nd messengers may have a wide variety of effects. Slide 9: Ionotropic and Metabotropic Receptors Reuptake, Enzymatic Degradation, and Recycling : Reuptake, Enzymatic Degradation, and Recycling As long as NT is in the synapse, it is active – activity must somehow be turned off Reuptake – scoop up and recycle NT Enzymatic degradation – a NT is broken down by enzymes