Lecture 2

Question 1

What are the 4 steps of the ablation and replacement method?

Answer 1

• gland that is suspected source of hormone affecting behaviour is surgically removed
• effects on behaviour observed
• hormone replaced by reimplantation or injection
• determination is made whether observed consequences of removal are reversed by hormonal replacement therapy

Question 2

Describe Berthold’s experiment w roosters and his main conclusions

Answer 2

• did ablation and replacement method w testes
• discovered testes are transplantable organs
• bc testes still worked after nerves severed, must be other form of communication (likely via blood)

Question 3

Which of these elements of behavioral endocrinology research correspond to description of action vs description of consequence?
- evolution
- mechanisms
- development
- function

Answer 3

Action (how): mechanisms, development
Consequence (why): evolution, function

Question 4

The dependent variable is the (predictor/outcome)
The independent variable is the (predictor/outcome)

Answer 4

outcome measured
predictor manipulated

Question 5

What is a quasi-experimental research design?

Answer 5

• between exp and non-exp
• looks at cause and effect relationships but often lacks key elements (eg random assignment)
• lack of random ass makes it harder to establish cause/effect

Question 6

What is a correlational research design?

Answer 6

• no manipulation of variables
• look @ relationships btw variables

Question 7

What is a longitudinal research design?

Answer 7

• looks @ changes in variables over time in same group
• problems: attrition, resource intensive

Question 8

What are immunoassays?

Answer 8

• analytical technique used for quantification of a hormone based on antigen-antibody rxn

Question 9

What is an antigen?

Answer 9

• molecule that can bind to a specific antibody (can be hormone we want to study)

Question 10

What is an antibody?

Answer 10

• protein made by plasma cells in response to antigen

Question 11

What are bioassays? What example was given in class?

Answer 11

• test effects of hormone and measure biological activity on living animal
  Ex. Human chorionic gonadotropin (hCG)
• hormone produced during pregnancy (found in urine)
• inject urine into rabbits
• if hCG is present, rabbit’s ovaries enlarge and show follicular maturation
• first pregnancy test!!!

Question 12

What are radioimmunoassays (RIA)?

Answer 12

• based on principle of competitive binding of antibody to antigen (hormone) that results in change in radioactivity

Question 13

How do radioimmunoassays work?

Answer 13

• test tubes w diff concentrations of hormone (unlabeled/cold antigen AND radiolabeled/hot antigen) and antibody used to benchmark hormone concentration
• measure radioactivity generated when unlabeled antigen (hormone) binds to antibody (displaces radiolabeled antigen)
• compare radioactivity to standard to figure out concentration of hormone

Question 14

What are enzyme linked immunosorbent assays (ELISA)?

Answer 14

• capture antibody on surface
• add antigen and then labelled antibody
• add substrate
• enzyme converts substrate into colourful product that can be detected

Question 15

What are the 3 types of ELISA? What do they have in common?

Answer 15

• Direct (enzyme-linked antibody binds to protein X directly)
• Indirect (enzyme-linked antibody binds to antibody that is binded to protein)
• Sandwich (antibody binds to bottom of well, protein binds, enzyme-linked antibody binds to protein)

**last antibody binding always conjugated to enzyme

Question 16

Immunocytochemistry is applied to _____
Immunohystochemistry is applied to ____
Both use antibodies to determine _____

Answer 16

cells
tissues
location of hormone in specific cell/tissue

Question 17

What is autoradiography?

Answer 17

• captures/visualizes radioactively labeled molecules in tissue
• photographic film overlayed w adjacent stained tissue

Question 18

What are blot tests?

Answer 18

• techniques used for transferring and detecting biomolecules using specific probes
• electrophoresis separates cells by size in gel; add antibody against protein of interest; strips show up where binding occurs

Question 19

WHat is in situ hybridization?

Answer 19

• locates and visualizes specific nucleic acid sequences (eg mRNA) that code for a specific protein
• similar to PCR covid testing

Question 20

Covid PCR testing is similar to ____ and rapid antigen testing is similar to ____

Answer 20

in situ hybridization; ELISA

Question 21

What are agonists and antagonists?

Answer 21

• agonist: mimics hormones; stimulates endocrine funct.
• antagonist: hormone blocker; inhibit endocrine funct.

Question 22

How does Positron Emission Tomography (PET) work?

Answer 22

• inject radiotracers for specific molecules/hormones
• scanner detects radioactivity as compound accumulates in diff regions

Question 23

How does fMRI work?

Answer 23

• uses magnetic fields to measure blood flow
• great spatial res, bad temporal res

Question 24

What do the terms “transgenic” and “knockout” mean?

Answer 24

• transgenic: animal in which gene has been inserted, altered, or deleted
• knockout: animal in which a specific gene has been inactivated

Question 25

CRISPR/Cas9 allows ______

Answer 25

precise editing of genes WITHIN organisms!!