Class Notes (922,171)
CA (542,732)
UTSC (32,897)
BIOC32H3 (132)
Lecture 10

Lecture 10 - Synaptic Plasticity, Fatigue, & the NMJ

7 Pages
63 Views

Department
Biological Sciences
Course Code
BIOC32H3
Professor
Kenneth Welch

This preview shows pages 1-2. Sign up to view the full 7 pages of the document.
Lecture 10
Readings:
Chapter 6 Communication Along and Between Neurons Section Synaptic Plasticity P.
202 –209
Chapter 10 Muscles and Animal Movement Section Motor Control in Arthropods P. 413
414.
Neuronal Plasticity
The modification of neuronal function as a result of experience
Synapse with prior experience
What we see in synapses is the activity of multiple axons synapsing on other axon
terminals and not the postsynaptic membrane
Changes on the presynaptic side classified into two categories:
oHomosynaptic: something internal to that axon; activity in the terminal itself
causes a change in its release of transmitter
oHeterosynaptic: when a closely associated axon terminal causes changes on
an presynaptic membrane; common that what we see in synapses
involvement of multiple axons that arent synapsing at the post-synaptic
membrane but with the axon terminal itself; changes are induced by the
action of a modulator substance released from another, closely apposed axon
terminal
Lasts longer than homosynaptic modulation
The neuromuscular junction
Homosynaptic facilitation:
oWe have frog muscle fibre with motor neurons synapsing on it in the curare
bath
oCurare: blocking ACh receptors on the post-synaptic membrane; depending
on its concentration in the synapse it will block it occupy ACh sites
www.notesolution.com
oIf we didnt do this, we would have enough neurotransmitter resulting in a
twitch every time we stimulate it we want to see things in the graded sense
oIf something is happening at the graded sense you need to tone the system
down with curare to see it
oIf given enough curare, it will lower the strength of the depol and wouldnt
reach threshold = no AP
oPoisoning it to get an EPSP that doesnt reach threshold
oWhat we see in regard to the epsps, as the degree of the epsp changes we can
actually measure that with our recording electrodes
oWhen we send two stimulation pulses triggering action potentials down the
axon in quick succession: the second postsynaptic potential will begin before
the first has subsided; the first one we see is a given depolarization and in
the second one we see a depolarization greater in magnitude than the first
oIt isnt just temporal summation more than JUST temporal summation
oThis is not just a summation but MORE than just the addition of 1+2 =
FACILITATION
Synaptic facilitation:
oThe AP arrives and causes depolarization until it reaches a threshold that
allows the opening of Ca2+ and Na+ channels
oThe extent of exocytosis is related to the amount of Ca+ available in the axon
terminal
oLike an EPSP, there is a pulse and then the SECOND AP
oThe Ca concentration rises even higher than it would with just one given
isolated AP
oThe intracellular Ca concentration BUILDS on top of what is already there
oEven more robust release of neurotransmitter
oFROG: This facilitation lasts for 100-200 milliseconds period of time over
which it takes for the Ca+ concentration to disperse on the inside of the
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
Lecture 10 Readings: Chapter 6 Communication Along and Between Neurons Section Synaptic Plasticity P. 202 209 Chapter 10 Muscles and Animal Movement Section Motor Control in Arthropods P. 413 414. Neuronal Plasticity The modification of neuronal function as a result of experience Synapse with prior experience What we see in synapses is the activity of multiple axons synapsing on other axon terminals and not the postsynaptic membrane Changes on the presynaptic side classified into two categories: o Homosynaptic: something internal to that axon; activity in the terminal itself causes a change in its release of transmitter o Heterosynaptic: when a closely associated axon terminal causes changes on an presynaptic membrane; common that what we see in synapses involvement of multiple axons that arent synapsing at the post-synaptic membrane but with the axon terminal itself; changes are induced by the action of a modulator substance released from another, closely apposed axon terminal Lasts longer than homosynaptic modulation The neuromuscular junction Homosynaptic facilitation: o We have frog muscle fibre with motor neurons synapsing on it in the curare bath o Curare: blocking ACh receptors on the post-synaptic membrane; depending on its concentration in the synapse it will block it occupy ACh sites www.notesolution.com
More Less
Unlock Document


Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit