Throughout the course we have discussed several papers that sought to answer a range of questions regarding endocrine systems and their specific agents. While focusing on the structure and function of particular endocrine systems, each paper also demonstrated how hormones facilitate behavioral and physiological traits (e.g., stress-related anxiety, learning, sex differences, learning & cognition, etc.). Several of these papers, investigated the effects of glucocorticoids in some manner on different physiological traits (e.g., immune-responses, learning, biorhythms, etc.). A common theme has been to critically evaluate each research paper and consider how the new information can shed light on our understanding from other studies, i.e., critically build our understanding of how hormone systems work, and how they interact. Choose 2 out of the 10 discussion papers, and provide the following. Suggestion: you will find it very useful to choose at least one paper from Discussion #s 7-10 in order to prepare for the next exam. Be certain to identify clearly which information corresponds to which study.
a) Specify the hormonal axis addressed in each study. Provide a sketch or flow chart for each axis (e.g., from lecture & N&C Fig 4-20, other recent axes). Be concise yet also as complete as possible. Identify all of the major steps/organizational levels (hypothalamus-pituitary-adrenal cortex), target cells/tissues (e.g., corticotrope cells within the pars distalis), their interactions (e.g., PVN release of corticotropic releasing hormone into median eminence, travels to corticotrope cells in pars distalis, triggers release of…), as well as feedback pathways. If possible, present these side-by-side to facilitate comparison. Be certain to label each interaction as inhibitory (-) or stimulatory (+), this can be accomplished with letters, or by color/stripe-coding between cells. If the base pathways are the same, alternate color/line coding can be used to differentiate the paths addressed in each study while using a single major axis diagram.
Figures should be more complete than N&C Fig 4-20; for example, in the HPGn axis which specific cells in the testes are targets for LH & FSH? For target cells at the end of the pathways what are the functions activated in those cells (e.g., receptor binding, expression and release IGF-1 in the liver,synthesis & secretion of Thyroxine by the follicular cells of the thyroid gland). The goal is to clearly define the 2 pathways and how they overlap or interact. For example, if the focus of the papers is on neural control, you can devote more of the figure to detailing interactions in the hypothalamus. If the interactions occur at the level of the pituitary and beyond, then only the minimal, essential detail is necessary at the level of the hypothalamus. Overall, try to balance detail with brevity.
b) For each paper describe the primary research question(s) that the paper sought to answer. Recall the required level of specificity and conciseness here.
c) Explain how the findings from each study shed light on how a bioregulator may interact with multiple pathways (or systems, e.g. neuro-, endo-, immuno-), by binding to a diversity of receptors, yielding multiple impacts on other systems. Specifically, how might these 2 pathways overlap or otherwise interact. In answering this section, particularly for similar pathways, consider how multiple signaling pathways can be triggered within the same target cells once activated by a particular hormone. Consider cross-talk both within cells and across cells (i.e., different axis pathways). How might multiple stressors alter the results of the 2 studies? How might the knowledge gained from one study inform the other? What are the implications for using hormonal control to address a particular clinical issue (e.g., disease, illness, behavior, etc.)?
BIOL414 Endocrinology Extra Credit I 2 Submission details:
The paper must not exceed 2, typed, double-spaced pages. Literature cited (if necessary) can be placed on a third page. Be complete, thorough, but also succinct in your answers.
Consider the brevity of research published in journals such as Science, where methods and details are condensed into footnotes, as a role model.
Use your flowchart/sketch optimally, to minimize text. E.g., consider using 1 page for your figure and one page to answer questions a & c. If you use this option, in addition to the figure, a single page of text, single spaced, using no smaller than 11-pt font for that page will be acceptable. However, your answers should also be specific, clear and concise: statements that are vague or open to wide interpretation will not merit credit.
Grading:*** The assignment will be graded approximately to the following scale, with ~half of the grade based on the figure and half on the interpretation:
0.0 points: Essentially. Sub-C level work, weak attempt, minimal, incorrect or incomplete information.
5.0 points: C to B level work, answers incomplete, missing critical components, generally adequate but possibly missing important detail, weak or mediocre analysis.
10.0 points: B to A level work, complete, clear information, thoughtful, observant, insightful analysis.
***Minus 0 – 5: You will lose points for poor grammar & writing.
The deadline for the paper is: 5 pm, May 9. You are welcome to submit your paper sooner – they will be graded in the order they are received. You are also welcome to meet with me to discuss your paper prior to its submission. Turn in either a printed copy or electronic file. If submitting an electronic file, it must use the following filename convention: BIOL414_EC1_YourLastName_YourFirstName.Late submissions, and files submitted without using this naming convention will not be accepted.