Lecture 19

Question 1

Who was Wilder Penfield and what did he discover?

Answer 1

Canadian Neurosurgeon, discovered the source of some individual’s seizure activities

Question 2

What does stimulus of the lateral hypothalamus in rats stimulate?

Answer 2

Eating

Question 3

What are self-stimulation studies?

Answer 3

Given the opportunity, rats will press a lever to obtain a current to lateral hypothalamus (VTA- Nucleaus Accumbens, reward path). People will do the same.

Question 4

What is transcranial magnetic stimulation and what does it do?

Answer 4

Magnetic coil is placed over the skull to stimulate the underlying brain tissue- can either induce or disrupt behaviour. Produces a brief but strong magnetic current resulting in a temporary current in the area of the brain directly below the coil.

Question 5

What is rTMS and what does it do?

Answer 5

Repeated TMS, is being used to treat a number of disorders such as stroke and depression, and alzheimers.

Question 6

What are optogenetics?

Answer 6

Transgenic technique that combines genetics and light to control targeted cells in living tissues. Channels that respond specifically to colours of light- used to control specific brain areas.

Question 7

What are chemogenetics?

Answer 7

Transgenic technique that combines genetics and synthetic drugs to activate targeted cells in living tissue.

Question 8

What are DREADDS?

Answer 8

Designer receptor exclusively activated by designer drugs- insert resceptor that responds to biological inert substance (clozapine N-oxide) -used to inhibit or excite neurons.

Question 9

What is electroencephalography? (EEG)

Answer 9

Measures the summed graded potentials from many thousands of neurons-changes as behaviour changes. -array of patterns in cortex

Question 10

Is the EEG ever silent?

Answer 10

No, only in death

Question 11

What is EEG useful for?

Answer 11

Useful for diagnosis of brain abnormalities.

Question 12

What are event-related potentials (EEG)?

Answer 12

Brain activity in response to a discrete stimulus

Question 13

What is one of the problems with EEG and how do we solve it?

Answer 13

Signals that we are looking for are hidden amongst the rest of the brains noise. Solution? Average responses across trials, analyze positive and negative deflections in signals.

Question 14

What are some of the advantages of EEG?

Answer 14

Noninvasive, relatively easy to convince uni students to participate, low cost, great temporal resolution

Question 15

How is an EEG heatmap read?

Answer 15

More activity in hotter zones-use waveforms to build and then estimate the location

Question 16

What are some of the issues with EEG?

Answer 16

Can’t image deeper strictures, utilizes “backward solution”.

Question 17

What are single neuron studies?

Answer 17

In animals, we insert electrodes directly into the brain and record single action potentials. Electrode is either implanted next to cells (extracellular) or inside (intracellular). Animal then behaves however it wants.

Question 18

What are some basic cell responses in the brain?

Answer 18

Neurons that encode line orientation, colour, etc

Question 19

What are some more complex cell responses in the brain?

Answer 19

Hands, faces, combinations of sound

Question 20

What are place cells?

Answer 20

Neurons maximally responsive to specific locations in the world-may create a spatial map in brain (has a tuning curve for places).

Question 21

What is computerized tomography?

Answer 21

X-ray technique that produces a 3D image of the brain.

Question 22

Who split the nobel prize for their discovery of place cells?

Answer 22

John O’Keefe, May Britt Moser, Edvard V Moser.

Question 23

How do we get a functional image in an MRI?

Answer 23

Using protons! Protons normally point all over the place. MRI uses a big magnet to align all the protons in a sample, and after alignment, we knock these protons at an angle so they spin, then gradually they realign with magnetic field. Protons then echo back the radio frequency that initally tipped them over.

Question 24

Does an MRI say anything about brain function?

Answer 24

No! It is simply an anatomical image.