Ionic Mechanisms of Synaptic Excitation Synaptic transmission - PowerPoint PPT Presentation

Apr 21, 2023 •243 likes •484 views

Ionic Mechanisms of Synaptic Excitation Synaptic transmission Synaptic input 1) Communication within the nervous system 2) A site of plasticity for learning and memory 3) A site of action for disease, psychoactive drugs Whimpy axon!

Ionic Mechanisms of Synaptic Excitation � Synaptic transmission Synaptic input 1) Communication within the nervous system 2) A site of plasticity for learning and memory 3) A site of action for disease, psychoactive drugs Whimpy axon!
Crayfish NMJ as a model for human brain synapses Neuromuscular Innervation Uni-terminal Multi-terminal Uni-neuronal Poly-neuronal Excitation Only Inhibition Often no APs Mammals Arthropods See Synapse Tutorial on class web site for review
Crayfish NMJ preparation
Example Data
Map Muscle Innervation Patterns (Also better distinguish number of axons in nerve 3 ) Synaptic Integration See G-PRIME for example of- Muscle Innervation - Cross Correlation
EPSP trying to reach AP threshold Synaptic integration Axon Hillock Dendrite spatial and temporal
Space constant important Time constant important Spatial summation Temporal summation
Synaptic Inhibition Two flavors: Algebraic Summation Shunting How do they work?
Synaptic Inhibition Stimulation of inhibitory nerve blocks AP production
Presynaptic inhibition � Presynaptic inhibition � reduces transmitter � release �
Types of Chemical Synaptic Transmission direct, fast indirect, ~slow
Action Potentials can arise from subthreshold depolarizations if they are not spontaneous
Stimulate presynaptic axon
Steps in ionotropic chemical synaptic transmission
Excitation: Conductance increase (resistance decrease): Channels in membrane open Membrane potential goes towards Vrev (Equil. Pot)
Vrev = Eion Results if EPSP were due to only Na + or K +
Isyn= g ACh (V m -V rev ) (Vm-Vrev)= Driving force Depolarizing because of large Na driving force -60 mV
Conductance change due to multiple ions
Inhibition: Conductance increase (resistance decrease): Membrane potential goes towards Vrev (Equil. Pot)
Most common fast transmittters Proof of Neurotransmitter Identity?? Presence Action Release Pharmacological Congruence Synthetic/packaging machinery
Release of Transmitter Snake Neuromuscular Junction Model
EM section of NMJ Freeze-fracture of NMJ
Brain Synapse Few vesicles at each synaptic site

Download Presentation

Download Policy: The content available on the website is offered to you 'AS IS' for your personal information and use only. It cannot be commercialized, licensed, or distributed on other websites without prior consent from the author. To download a presentation, simply click this link. If you encounter any difficulties during the download process, it's possible that the publisher has removed the file from their server.

Recommend

Synaptic Learning Rules Computational Models of Neural Systems Lecture 4.1 David S. Touretzky

Synaptic Learning Rules Computational Models of Neural Systems Lecture 4.1 David S. Touretzky October, 2019 Why Study Synaptic Plasticity? Synaptic learning rules determine the information processing capabilities of neurons. Synaptic

888 views • 40 slides

1 Excitatory Inhibitory excitation inhibition 2 excitation excitation inhibition

1 Excitatory Inhibitory excitation inhibition 2 excitation excitation inhibition inhibition Synaptic strength (receptors, transporters, Metabolic changes transmitter release, etc.) (anoxia, hypoglycemia) Membrane properties Cell

264 views • 9 slides

3/10/16 Steps in transmitter March 9, 2016 What is the cause of release

3/10/16 Steps in transmitter March 9, 2016 What is the cause of release Synaptic T ransmission Refresher (cont) synaptic delay?- over 1 ms Crawdad Lab Exercises 5 & 6 Synaptic input EPSP

501 views • 5 slides

Synaptic Failure Rao Prnpuu, Oliver Hrmson Introduction The Aim: - Understanding the role of

Synaptic Failure Rao Prnpuu, Oliver Hrmson Introduction The Aim: - Understanding the role of synaptic failure (SF) in the brain Two parts: - Overview of previous studies, both computational and biological - Creating a model and running

516 views • 26 slides

Synaptic Scholars Senior Presentations April 28, 2014 Crane Room, Paige Hall The Institute for

Synaptic Scholars Senior Presentations April 28, 2014 Crane Room, Paige Hall The Institute for Global Leaderships SYNAPTIC SCHOLARS PROGRAM The Synaptic Scholars program is a leadership program, meant to provide a forum for students to

621 views • 12 slides

Synaptic Plasticity and the NMDA Receptor Computational Models of Neural Systems Lecture 4.2

Synaptic Plasticity and the NMDA Receptor Computational Models of Neural Systems Lecture 4.2 David S. Touretzky October, 2019 Synaptic Plasticity Is A Major Research Area Long Term Potentiation (LTP) Reversal of LTP Long Term

710 views • 42 slides

Inferring Synaptic Update Rules in a Neural Simulator Honours Thesis Ryan Fayyazi April 2020

Inferring Synaptic Update Rules in a Neural Simulator Honours Thesis Ryan Fayyazi April 2020 HMM for static neural circuit Synaptic Weight Matrix Membrane Potential Intracellular [Ca 2+ ] Calcium Fluorescence euroscience Background

409 views • 27 slides

Emergent Intelligence via Synaptic Tuning Keith L. Downing The Norwegian University of Science

Emergent Intelligence via Synaptic Tuning Keith L. Downing The Norwegian University of Science and Technology (NTNU) Trondheim, Norway keithd@idi.ntnu.no January 19, 2015 Keith L. Downing Emergent Intelligence via Synaptic Tuning Donald Hebb

416 views • 20 slides

Synaptic noise and its consequences University of London, UK) on the integrative properties of

(Courtesy of Alex Thomson, Synaptic noise and its consequences University of London, UK) on the integrative properties of cortical neurons Le bruit synaptique et ses consquences sur les proprits intgratives des neurones corticaux Alain

731 views • 61 slides

Huntingtons Disease 1) signal transmission between NS components

3/8/16 March 7, 2016 Synaptic T ransmission Refresher (cont) Crawdad Lab Exercise 8 Synaptic transmission Huntingtons Disease 1) signal transmission between NS components and effectors 2) A

241 views • 7 slides

Neurobiology of Stress, Depression, and Antidepressants: Remodeling Synaptic Connections

Neurobiology of Stress, Depression, and Antidepressants: Remodeling Synaptic Connections Ronald S. Duman, PhD Department of Psychiatry Yale University School of Medicine Mood Disorders Depression affects ~17% of the population: higher

2.64k views • 49 slides

Synaptic plasticity in a cortical microcircuit model: different scenarios Renan O. Shimoura,

Synaptic plasticity in a cortical microcircuit model: different scenarios Renan O. Shimoura, Antonio C. Roque Physics Department, FFCLRP, University of So Paulo, Ribeiro Preto, SP, Brazil Laboratrio de Sistema Neurais (SisNe)

368 views • 21 slides

Molecular Psychiatry An atypical antidepressant drug regulates synaptic plasticity Nature

4/9/2014 Molecular Psychiatry An atypical antidepressant drug regulates synaptic plasticity Nature Publishing Group Impact Factor: 14.897 (2012) 1/135 Psychiatry 7/251 Neuroscience 5/290 Biochemistry & Zhang, H.,

175 views • 4 slides

Intrinsic synaptic modulation in vertebrate brains: Depression Facilitation Mixed Dietmann et

Intrinsic synaptic modulation in vertebrate brains: Depression Facilitation Mixed Dietmann et al 2000 Sites of Possible Change for Plasticity Facilitation: Minis same size, increase in frequency Residual Ca hypothesis for facilitation:

420 views • 23 slides

Neuronal Cell Death and Synaptic Pruning driven by Spike-Timing Dependent Plasticity Javier

Neuronal Cell Death and Synaptic Pruning driven by Spike-Timing Dependent Plasticity Javier Iglesias 1 , 2 and Alessandro E.P . Villa 2 ICANN 2006 Athens, 2006-09-11 1 Information Systems Department, University of Lausanne, Switzerland 2

582 views • 25 slides

In silico stochastic simulation of Ca 2+ triggered synaptic release Andrea Bracciali Enrico

In silico stochastic simulation of Ca 2+ triggered synaptic release Andrea Bracciali Enrico Cataldo Pierpaolo Degano Marcello Brunelli Dipartimento di Informatica Dipartimento di Biologia Universit` a di Pisa Universit` a di Pisa {

706 views • 31 slides

Foundations I Fall, 2016 Synaptic Transmission I Neuromuscular Junction Neuromuscular Junction

Foundations I Fall, 2016 Synaptic Transmission I Neuromuscular Junction Neuromuscular Junction junctional folds Neuromuscular Junction Transmitter Release Del Castillo and Katz (1954) m 0.9 mM Ca++ and 14 mM Mg++ Transmitter Release Fatt

780 views • 65 slides

Multimodal i-vectors to Detect and Evaluate Parkinsons Disease Nicanor Garca 1 , Juan Camilo

Multimodal i-vectors to Detect and Evaluate Parkinsons Disease Nicanor Garca 1 , Juan Camilo Vsquez-Correa 1 , 2 , Juan Rafael Orozco-Arroyave 1 , 2 , and Elmar Nth 1 , 2 1 Faculty of Engineering, University of Antioquia, Medellin,

441 views • 21 slides

QUALITATIVE GAIT ABNORMALITIES OF NEUROLOGICAL TYPE, CLINICAL CHARACTERISTICS AND DISABILITY IN

QUALITATIVE GAIT ABNORMALITIES OF NEUROLOGICAL TYPE, CLINICAL CHARACTERISTICS AND DISABILITY IN OLDER COMMUNITY-DWELLERS WITHOUT NEUROLOGICAL DISEASES Inzitari M 1,2 , Metti A 3 , Rosso AL 3 , Udina C 1,2 , Prez LM 1 , Verghese J 4 , Newman AB

934 views • 12 slides

CHEMOTHERAPY IN ELDERLY PATIENTS WITH PANCREATIC CANCER Akshjot Puri, MD Post Graduate Year 5

CHEMOTHERAPY IN ELDERLY PATIENTS WITH PANCREATIC CANCER Akshjot Puri, MD Post Graduate Year 5 MENTOR: Madappa N. Kundranda, MD. PhD. CASE A 77 yo female, good PS, presents with non-specific epigastric pain and pruritus for 2 months No other

294 views • 10 slides

Cell Membranes Function as Integrative Systems Understanding how cell membranes molecules

Dr. Mircea Leabu - Membrane Transport (lecture's slides) Cell Membranes Function as Integrative Systems Understanding how cell membranes molecules cross-talk in assuring the membrane functioning 1. Cell Membranes Allow Exchanges of

494 views • 12 slides

TRADE SECRETS Trade Secret A trade secret can be any formula,pattern,idea,process,physical

TRADE SECRETS Trade Secret A trade secret can be any formula,pattern,idea,process,physical device or a compilation of information which provides its owner a competitive advantage in the market. A trade secret is expected to be treated in such

699 views • 49 slides

Using CNNs to understand the neural basis of vision Michael J. Tarr February 2020 AI Space

Using CNNs to understand the neural basis of vision Michael J. Tarr February 2020 AI Space Humans Future? Performance Deep AI 1980s- 2000s PDP Early AI Cognitive Plausibility Biological Plausibility Different kinds of AI

954 views • 34 slides

Introduction to Machine Learning Perceptron Barnabs Pczos Contents History of Artificial

Introduction to Machine Learning Perceptron Barnabs Pczos Contents History of Artificial Neural Networks Definitions: Perceptron, Multi-Layer Perceptron Perceptron algorithm 2 Short History of Artificial Neural Networks 3

836 views • 42 slides