What are the 4 steps of the ablation and replacement method?
- 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
Describe Berthold’s experiment w roosters and his main conclusions
- 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)
Which of these elements of behavioral endocrinology research correspond to description of action vs description of consequence?
- evolution
- mechanisms
- development
- function
Action (how): mechanisms, development
Consequence (why): evolution, function
The dependent variable is the (predictor/outcome)
The independent variable is the (predictor/outcome)
outcome measured
predictor manipulated
What is a quasi-experimental research design?
- 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
What is a correlational research design?
- no manipulation of variables
- look @ relationships btw variables
What is a longitudinal research design?
- looks @ changes in variables over time in same group
- problems: attrition, resource intensive
What are immunoassays?
- analytical technique used for quantification of a hormone based on antigen-antibody rxn
What is an antigen?
- molecule that can bind to a specific antibody (can be hormone we want to study)
What is an antibody?
- protein made by plasma cells in response to antigen
What are bioassays? What example was given in class?
- 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!!!
What are radioimmunoassays (RIA)?
- based on principle of competitive binding of antibody to antigen (hormone) that results in change in radioactivity
How do radioimmunoassays work?
- 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
What are enzyme linked immunosorbent assays (ELISA)?
- capture antibody on surface
- add antigen and then labelled antibody
- add substrate
- enzyme converts substrate into colourful product that can be detected
What are the 3 types of ELISA? What do they have in common?
- 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
Immunocytochemistry is applied to _____
Immunohystochemistry is applied to ____
Both use antibodies to determine _____
cells
tissues
location of hormone in specific cell/tissue
What is autoradiography?
- captures/visualizes radioactively labeled molecules in tissue
- photographic film overlayed w adjacent stained tissue
What are blot tests?
- 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
WHat is in situ hybridization?
- locates and visualizes specific nucleic acid sequences (eg mRNA) that code for a specific protein
- similar to PCR covid testing
Covid PCR testing is similar to ____ and rapid antigen testing is similar to ____
in situ hybridization; ELISA
What are agonists and antagonists?
- agonist: mimics hormones; stimulates endocrine funct.
- antagonist: hormone blocker; inhibit endocrine funct.
How does Positron Emission Tomography (PET) work?
- inject radiotracers for specific molecules/hormones
- scanner detects radioactivity as compound accumulates in diff regions
How does fMRI work?
- uses magnetic fields to measure blood flow
- great spatial res, bad temporal res
What do the terms “transgenic” and “knockout” mean?
- transgenic: animal in which gene has been inserted, altered, or deleted
- knockout: animal in which a specific gene has been inactivated
