New version page

CU-Boulder PSYC 2012 - bio psych lecture 6 notes

This preview shows page 1 out of 2 pages.

View Full Document
View Full Document

End of preview. Want to read all 2 pages?

Upload your study docs or become a GradeBuddy member to access this document.

View Full Document
Unformatted text preview:

1/29/15 – Lecture 6 – Synaptic Transmission- Goal: to discover how an action potential from one neuron effects another - Action Potential Propagation: domino effect of action potential down the axon of the neurono 1. Influx on Na+ from AP flows into adjacent membrane areao 2. New patch of membrane depolarizes, forms action potential, which depolarizes the next patch of membrane Opens the next section’s Na+ channel and keeps goingo 3. Pervious patch cant reform action potential because it is in the refractory period due to closing and inactivation of Na+ channels during hyper polarization Only moves in one direction, down the axon to synapse -> closed -> open -> inactivated (refractory period/ hyper polarization) -> de-inactivated -> closed -> ect- Saltatory Conductiono Myelin sheath surrounds axon except bare patches on the axon called “Nodes of Ranvier” Action potentials “jump” from node to node because myelin insulates the axon, allowing less ions to flow out the membrane Saltatory: jumping, speeds the rate of conduction and propagation down the axon- Allows for fast and complex messages being sent- Synaptic Gapo The axon of one neuron comes close to the dendrite of the new neuron but doesn’t actually touch The action potential allows for the release of special chemicals called neurotransmitters across the synaptic gap- Neurotransmitters: chemicals produced by the presynaptic neuron and released due to the action potential, finally effects the post synaptic neurono 3 Main classes of Neurotransmitters Small Molecule: amino acids (glycine, glutamate) or synthesized from them or other metabolites (dopamine, serotonin, norepinephrine)- Synthesized – in the axon- Stored – in vesicles in the axon terminal Peptide: long chains of amino acids linked together to form a peptide or protein chains- Synthesized – in the cell body- Stored – in secretory vesicles  Transmitter Gases: gases synthesized from atoms (NO and CO)- Synthesized – in the axon terminal- NOT stored, immediately diffused out of the cello Neurotransmitters Released and Synaptic Transmission 1. Action potential travels down axon into axon terminal 2. Opens voltage gated Ca2+ channels- Allows Ca2+ to flow into the cell down its concentration gradient 3. Causes fusion of neurotransmitter vesicles with the membranes or the synthesis of gas neurotransmitters 4. Fusion causes vesicles to dump neurotransmitters into the synaptic cleft/ gap- Most neurons release one main type of neurotransmitterso Neurotransmitter Systems: groups of neurons using the same neurotransmitter through out the brain and the nervous system 4 Major Neurotransmitter Systems- Dopaminergic: uses dopamine within brain to regulate reward and movement- Noradrenergic: uses norepinephrine within brain to regulate arousal and attention- Serotonergic: uses serotonin within brain to regulate mood and compulsions- Cholinergic: uses acetylcholine within brain to regulate arousal and attentiono When Neurotransmitters are released…? Neurotransmitters bind to post synaptic proteins called receptors (found on dendrites of post synaptic neurons that bind to neurotransmitters)- After binding they make changes to post synaptic cells 2 Main Types of Receptors- Ionotropic: binding of Neurotransmitters directly opens the ion channel in the receptor and allows ions to flow into the cello Ligand – gated ion channels- Metabotropic: binding of neurotransmitters doesn’t directly open an ion channel but rather indirectly opens an ion channel by activating other intracellular proteinso Opens and closes the channels near


View Full Document
Loading Unlocking...
Login

Join to view bio psych lecture 6 notes and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view bio psych lecture 6 notes and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?