7.13 Molecular mechanism involved in neurotransmetter release IX

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Del curso dictado por Peking University

Advanced Neurobiology I

247 calificaciones

Peking University

Advanced Neurobiology I

247 calificaciones

Hello everyone! Welcome to advanced neurobiology! Neuroscience is a wonderful branch of science on how our brain perceives the external world, how our brain thinks, how our brain responds to the outside of the world, and how during disease or aging the neuronal connections deteriorate. We’re trying to understand the molecular, cellular nature and the circuitry arrangement of how nervous system works. Through this course, you'll have a comprehensive understanding of basic neuroanatomy, electral signal transduction, movement and several diseases in the nervous system. This advanced neurobiology course is composed of 2 parts (Advanced neurobiology I and Advanced neurobiology II, and the latter will be online later). They are related to each other on the content but separate on scoring and certification, so you can choose either or both. It’s recommended that you take them sequentially and it’s great if you’ve already acquired a basic understanding of biology. Thank you for joining us!

De la lección

Neurotransmitter release

Let's learn more about the neurotransmitter release.

7.1 How does Ca2+ control neurotransmitter release I8:23

7.2 How does Ca2+ control neurotransmitter release II11:46

7.3 How does Ca2+ control neurotransmitter release III7:27

7.4 How does Ca2+ control neurotransmitter release IV10:18

7.5 Molecular mechanism involved in neurotransmetter release I7:56

7.6 Molecular mechanism involved in neurotransmetter release II7:11

7.7 Molecular mechanism involved in neurotransmetter release III5:27

7.8 Molecular mechanism involved in neurotransmetter release IV11:00

7.9 Molecular mechanism involved in neurotransmetter release V14:23

7.10 Molecular mechanism involved in neurotransmetter release VI12:35

7.11 Molecular mechanism involved in neurotransmetter release VII17:53

7.12 Molecular mechanism involved in neurotransmetter release VIII12:40

7.13 Molecular mechanism involved in neurotransmetter release IX7:59

7.14 Molecular mechanism involved in neurotransmetter release X13:25

Conoce a los instructores

Yan Zhang
Professor
School of Life Sciences, Peking University
Yulong Li
Research Fellow
School of Life Sciences, Peking University

Last time we have already discussed in detail about,

maybe the toxicology and about chemical approach to

identify the key molecular machinery, namely the snail complex, okay?

The work originally people identified synaptic writing so

the neurotoxin assay, understanding a substrate.

And then Gene Rossman, his group,

using the biochemical approach purified the NSF, and

ATPase that is critical to understand to likely transmit and reduce and

identify its membrane receptors, the so-called snap receptor, snares.

And it turns out they are the same, okay.

And we are going to discuss briefly yet

another approach which is using the genetic approach.

And one of the classical papers listed here conducted by Randy Schekman.

Still not in Berkeley.

Okay.

So in early 1980s this is a cell paper.

Identification of 23 complementation groups required for

post-translational events in the yeast secretory pathways.

So Randy is a well-established biochemist,

even though his classical work that we will discuss today is based on genetics.

Okay.

So, he and Jim Rossman, actually, also share some background.

They were out, from the Stanford biochemistry department.

So Jim Rossman has served, in the past as a chairman,

for the biochemistry department at Stanford.

Where Randy Shekman was a grad student, in that department.

Working with, Arthur Cumbrick.

Another great American biochemist,

who also got his Nobel prize by identification of DNA polymers.

Okay, so, both Randy and Gene Rossman that we discussed last time,

they have the history, all been associated with Stanford biochemistry department.

If I'm aware they use this biochemical approaches to understand.

Where this paper that Randy and

his technicians and students, they designed a very

screening acid.

Okay?

So again, as a biochemist,

I was joking saying they have this is three essential tools.

Three essential kits in their hands to ascertain different biological processes.

Okay, one is running a jowl, right,

I was joking, the other one will be centrification, right?

If you still remember.

The third one will be, run some kind of columns, okay?

Well, in this case, what it did actually, is using the yeast genetics.

So they demonstrate that using a special centrifugation process,

they can separate the mutant yeast versus the wild type yeast.

So this is the different collection of the centrifugation

that separate the special yeast cells by their density.

Okay and here demonstrating a mutant yeast

they previously identify that has abnormal vacuum.

Okay, it turns out the yeast has vacuum and if you have this abnormal vacuum.

The yeast density is different that water, okay?

So in their acid as you can see that most of this fracking here listed

are all the well type, has a normal density.

Well there is this mutant, this has

very different ones and then can be clearly cut, separated.

Okay?

So in their case so they were thinking well if

they can conduct mutagenesis in yeast, and

then using this [INAUDIBLE] protocol,

just by centrification in a separate different

strain of yeast despite that physical density.

Then you can collect a lot of mutants.

And better than that, what it did, using the powerful yeast genetics is

they conduct a temporary geo-sensitive screening.

Meaning that only the yeast that in our now optimal temperature

if they have their difference in density, they will collapse.

In the optimal temperature, the protein even though it is mutated

can still be functional, and therefore can support the yeast to grow.

So in this way they can generate a screen that can identify

those essential gene that might be important for

survival of yeast by simply screen in a different temperature.

While maintaining them in a optimal temperature

while the protein at least is partially functional.

So, this screen, they identified many, many mutants.

So this is demonstrating that using their enrichment method.

And TS means the temperature sensitive.

So they can screen many different colonies

in which as enrichment method as you can see, that they can get.

For example, close to 200

mutants were in this without enrichment, you only got 2, okay?

So this weight, they can enrich it.

So here's a problem, after your screening identify twin,

more than a 150 mutants and

they are all temperature sensitive mutants.

The problem is how do you know whether they are hitting the same gene.

Okay.

In their title as in here

they demonstrate that using this EMS, which will somehow modify

DNA nucleic acid and introduce single point notation.

The modified DNA actually goes through the DNA replication.

You will, can mutate it.

So they identify the so-called second mutant, second with secreting, okay.

Circulatory secreting mutant, second mutant.

As you can see this say, the count is at 23 different mutants

out of this more than 150 colonies.

So how do you know?

They are belonging to those 23 groups

rather than more 150 different groups.

How did the authors know?

And if you were lead how do you know?

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