Principles of Neuroscience Lecture 21 Looking at Neuronal Function

Question 0

What was the first technology used to look at the brain?

What was the capabilities of this technology?

Answer 0

The microscope

We were able to see cells, neurons

Question 1

What is neuro informatics and give some of the fields that it combines

Answer 1

It is the integration of many sub fields of neuroscience

Neuro chemistry
Structure
Function
Morphology
Location
Electricity
Ontogeny
Homology

Question 2

What did Brodmann do?

Answer 2

He created a map of the brain, differentiating between areas with different neurons

Question 3

Describe the difference between magnifications and resolution

Answer 3

Magnification: making something bigger
Resolution: making an image clear, being able to differentiate between two dots

Question 4

What did Ernst Abbé define?

Answer 4

He defined the limit of diffraction

There is a physical law that states that there is a point past which we can not resolve an image

Question 5

What does the electron microscope allow us to do?

What are some limitations of the electron microscope?

Answer 5

The electron microscope allows us to resolve images of very small structures, ie we can see individual synapses

Limitations:
There is a size, smaller than which we cannot resolve the image
The process of preparing a tissue for the EM is such that the tissue is so far from living.

Question 6

Give a few of the new technologies that subvert the problem of the limit of diffraction

Answer 6

1. Using fluorophores
   Eg. Tag antibodies that bind to synaptic proteins fluorescently. We can now see where the synapses on a neuron are happening
2. Super resolution microscopy
   Eg. PALM & STORM
   These technologies determine the precise location of molecules is a tissue.
   We are not seeing an actual image of the molecules, but instead an indication on a map where they all are

Question 7

What is temporal resolution?
Why is it important?
Give an example of it

Answer 7

This is how good a technology is at differentiating two events that occur in quick succession

Eg. Microelectrodes in a single neuron can detect the electrical potential changes that constitute a single action potential

Question 8

Describe the function of the Patch clamp electrode tip

Answer 8

The hole is in the size range of a single protein (ion channel) on a cell membrane

The patch clamps forms a very tight seal on the area of membrane, and can detect the activity of a single ion channel

Question 9

Describe how the patch clamp electrode tip technology has given us information about ion channels

What is the structure of an ion channel?

Answer 9

With this technology we can determine the excitability, as well as structure of an individual ion channel

It is a multimer with a channel just large enough for ions to flow through

Question 10

Describe the interaction between spatial and temporal resolution

Answer 10

Different technologies have different capabilities in terms of spatial and temporal resolution

Also, the technologies have varying degrees of invasiveness