Lecture 7 vocab

Question 1

What is the molecular level of how we smell and taste called?

Answer 1

Identifying the odor and taste cues-characterize the neurons that relay the signal and the relevant genes/molecules

Question 2

What is the goal of immunofluorescence and immunohistochemistry(IHC)?

Answer 2

To visualize specific proteins in tissues

Question 3

What approach is taken with immunofluorescence and immunohistochemistry(IHC)?

Answer 3

With specific antibodies and stains/dye

Question 4

What steps are taken with immunofluorescence?

Answer 4

Add primary antibody, add secondary antibody conjugated to fluorophore, then shine UV light, and visualize using fluorescence

Question 5

What steps are taken with immunohistochemistry(IHC)?

Answer 5

Add primary antibody, add secondary antibody conjugated to HRP, add chromogen, HRP catalyzes reaction to produce colored precipitate, colored precipitate accumulates around location of antigen, visualize using brightfield microscopy

Question 6

What does IHC identify?

Answer 6

Different subsets of taste receptor cells, it stains for taste receptor proteins in a taste bud

Question 7

What does IHC use antibodies against?

Answer 7

ENaC and TrpM5

Question 8

In the expression analysis, what’s the goal of immunofluorescence and IHC?

Answer 8

To use sequencing to quantify gene expression(typically at RNA transcript level)

Question 9

In the expression analysis, what is the approach taken with immunofluorescence and IHC?

Answer 9

Transcriptomics(measure all transcripts)

Question 10

What are examples of transcriptomics?

Answer 10

Microarray and RNAseq

Question 11

What does RNAseq do?

Answer 11

Counts mRNA transcripts to quantify gene expression

Question 12

What does RNAseq analysis do?

Answer 12

It reveals classes of taste receptor cells expressing different genes at different levels

Question 13

What does the cellular level do?

Answer 13

It identifies the neurons that relay the signal

Question 14

What do channel blocking toxins help do?

Answer 14

They help characterize neuron types

Question 15

What is APV?

Answer 15

It blocks glutamate receptors(NMDA type specifically) and provides info about neurotransmitters used by cells of interest

Question 16

What is curare?

Answer 16

It blocks acetylcholine receptors(nAChR type specifically) and provides info about neurotransmitters used by cells of interest

Question 17

Which neurons relay the channel blocking toxin signals?

Answer 17

Calcium imaging

Question 18

What is GCaMP?

Answer 18

Its a calcium indicator

Question 19

What does calcium imaging reveal?

Answer 19

It reveals properties of taste responsive cells in brain

Question 20

What is an alternative to calcium imaging?

Answer 20

Voltage sensitive dyes

Question 21

What is voltage sensitive dye?

Answer 21

Fluorescence of dye changes to reflect changes in membrane potential directly

Question 22

Who pioneered the electrophysiology experiment that recorded the intracellular squid giant axon?

Answer 22

Hodgkin and Huxley

Question 23

What is the purpose of current-clamp electrophysiology?

Answer 23

To learn about the type of neurons and its ion channel

Question 24

What is the procedure to preforming a current-clamp electrophysiology?

Answer 24

Apply/inject a known current(to mimic the current that would be produced if the cell received input(s) from other neurons) and then measure resulting change in membrane potential

Question 25

What do different types of neurons have when it comes to spiking patterns?

Answer 25

Different spiking patterns

Question 26

What is electrophysiology: patch clamp?

Answer 26

For small cells. it is when you patch onto the outside of the cell rather than piercing cell, it enables recording from single channel(hypothetically)

Question 27

What's the goal with the circuit level?

Answer 27

To understand how signals and cells interact

Question 28

What does optogenetics allow?

Answer 28

It allows selective activation of neurons(with light)

Question 29

What is channelrhodospsin-2? What is it used for?

Answer 29

It is a light gated cation channel and its used in optogenetics

Question 30

What initiates an AP in optogentics?

Answer 30

Blue light pulses

Question 31

What can optogenetics help?

Answer 31

It can help identify neural circuits

Question 32

What does blue light case in optogenetics?

Answer 32

It causes neurons expressing channelrhodopsin2 to spike

Question 33

In what region of the brain does blue light activate neurons to express channel rhodopsin?

Answer 33

In the SFO brain region

Question 34

What are the 3 considerations you have to make in imaging techniques?

Answer 34

Temporal resolution, spatial resolution, and invasivness

Question 35

What are the 2 classes of human imaging & activity monitoring approaches?

Answer 35

Neural activity that leads to changes in blood flow being measured by functional imaging(ex. fMRI) and neural activity generating electrical signals measured by electrophysiological techniques(ex.EEG)

Question 36

What is fMRI?

Answer 36

It stands for functional magnetic resonance imaging and it measures blood oxygenation(BLOD:Blood oxygen level dependent contrast)

Question 37

What imaging technique has poor temporal resolution(6-8sec) and relatively good spatial resolution?

Answer 37

fMRI

Question 38

What is fMRI helpful for?

Answer 38

It helps us better understand how the healthy brain works and to investigate disruptions in disease states

Question 39

What does the fMRI do?

Answer 39

It compares relative differences in brain activity between two or more conditions, ie. rest vs. performing a task in the scanner

Question 40

What does electroencephalogram(EEG) do?

Answer 40

It records neural activity at the scalp

Question 41

What imaging techniques has has good temporal resolution, has poor spatial resolution due to space distorted by scalp, and is non invasive?

Answer 41

EEG

Question 42

What does the average EEG signal provide?

Answer 42

Event-related potential(ERP)

Question 43

What is ERP?

Answer 43

It can be measures of reaction time or response to a stimulus

Question 44

What is GWAS(genome-wide association study)

Answer 44

It is an observational study of a genome-wide set of genetic variants in different individuals to see if any variant is associated with a trait