Bio 250 Introduction to Research

Does daily limited access to a highly palatable food induce binge eating in rats?

Spring 2007

last updated 20 July 2007 at 10:49 am

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Deadlines

For papers to be presented on Tuesday, presenters must make papers available to classmates by noon on the preceeding Friday.

For papers to be presented on Thursday, presenters must make papers available by noon on the Monday, the week of the presentation.

To meet these deadlines, presenters must have their papers approved by Dr. Davis with sufficient time to either provide photocopies (if papers are not available on line) or links to on-line papers.

Assistance with Presentations

Dr. Davis expects to meet with students as they prepare their presentations. Students should schedule appointments well in advance. Those presentations scheduled for Tuesdays are problematic in that Dr. Davish has histology lab on Monday afternoon and will not be able to meet on Monday afternoon. Monday evening is too late to meet. Therefore, with sufficient advance notice, Dr. Davis can arrange to meet with presenters on Sunday night.

Selecting papers for presentation

Papers should be published in peer-reviewed scientific journals. Review papers are not appropriate.
Papers should be of a reasonable length (typically 3-12 pages.)
All three papers presented on a given day should have a common theme or topic.

Dr. Davis must approve all papers for presentation in advance! To do so, he must have at least one day to examine the candidate paper before making a decision as to its appropriateness. Take this into account together with the deadlines posted above to avoid last-minute rush decisions.

For the first round of presentations, all papers must be related in some way to the control of feeding behavior or disorders of appetite.
Potential themes may include
....role of the hypothalamus (or other brain region) in the control of feeding
....Factors that promote (or inhibit) food intake or appetite
....Sensory specific satiety in humans or animal models
....Animal models of feeding behavior
....circadian rhythms and food intake
....abnormal feeding behaviors (anorexia, bulemia, binge eating, etc.) and the underlying causes and/or treatments
These are simply ideas to get students thinking about themes or topics. Talk with Dr. Davis about the many other possibilities.

It is anticipated that for the second and third round of presentations student will be free to choose whatever topics they wish (so long as the 3 papers presented on a day have a common theme.)

Audience Participation Grades

Participation by the audience is a very important aspect of a successful journal club. Thus participation grades will be assigned by the professor based on the following criteria:

-2 Absent for the entire session (unless prior notification for an excused absence e.g. serious illness, atheletic competition, interview, etc.)
-1 Late for a session
+1 present, but no contribution to the discussion
+2 contributed to the discussion by asking, addressing, or answering a question or making a comment, etc.
+3 made one or more significant/important/insightful contribution(s) by asking, addressing, or answering a very good question or making an important point, or by participating in all three presentation by asking a question or making a comment.
+4 exemplary participation (especially important contribution to the discussion, especially insightful question or comment, multiple significant insights, etc.)

Course participation grade is calculated as the sum of all participation points awarded over all sessions and converted to a percentage (number of points earned of the total possible points.)

The instructor will update students periodically on their current participation grade.

Animal Care Duties

Animal care duties begin on Tuesday of the week you are scheduled, run through the weekend and include the following Monday. A new duty cycle begins each Tuesday with new personel. It is essential that these duties be taken seriously. The animals and the animal room are subject to unannounced inspections. If it appears that either have been neglected, a strong participation grade penalty (-10 points) will be levied against both individuals assigned to duty that week.

Each day of your animal care duty (including Saturday and Sunday) you are responsible for making sure

• each animal has a water bottle at least 3/4 full

• each rat has an abundance of rat chow (except for those animals that will be food deprived beginning at 1:30 on the Wednesday before an experiment day. Dr. Davis will leave a note as to which animals are to be food deprived.)

• the temperature in the room is within the desired range (20-21C) If not, report to Dr. Davis (phone numbers are on each animal tag.)

• bedding is suffiently clean. Bedding will be replaced every Thursday.

  • On Thursdays when we do not conduct an experiment, the Animal Care Personel will change the bedding.

  • On Thursdays when we conduct the experiments, the Early Birds will stay late after lab and put new bedding in each cage.

• the animal room is neat and clean. If the floor is dirty, sweep it. If the room appears disorderly, straighten it.

• Each day when you've completed your duties, check off and sign the Duty Sheet on the clip board in the animal room.

Early Bird Duties

Early Birds are responsible for making sure the experiments can begin on time on experimental day. As such, they will arrive early (no later than 7 am) to assist Dr. Davis is getting the cages, animals, test foods, balances, data sheets, etc. ready to go.

Early Bird Duties include

From 7 am until the experiment begins:

transferring the animals from the Environmental Chamber to Room 212 at 7 am to allow the animals to acclimate to the new room for one hour befoe the experiment begins.

Removing water from animals at 7 am.

Weigh and record the weight of each rat.

Organize the cages on the lab tables according to which experimental treatment each animal will undergo that day.

Remove the bedding from each cage and place old bedding in large black trash bags to be taken to the loading dock.

Carefully weigh, label, and record the values for the foods to be used during the experiment.

Place the labeled food containers by the rat for which it was prepared.

Make sure balances are set up, turned on, and working properly.

Make sure clipboards and data sheets are arranged appropriately.

Distribute the food containers.

Upon the completion of the experiments:

Remove all food residue from the cages.

Place clean bedding in each cage.

Make sure all animals have fresh water and rat chow.

Return all animals to the Environmental Chamber.

Wash all labware (including food cups and lids) and leave it stacked to air dry.

Store balances.

Collect data sheet(s) and give to Dr. Davis

Sweep the floor.

Wipe the table tops with disinfectant solution.

Drop trash bags with old bedding on the loading dock.

Check with Dr. Davis for any additional tasks.

 

Instructions and Data Sheets

Spreadsheet with rat body weights

The questions

Background: Rats maintained ad libitum on rat chow exhibit sensory specific satiety (SSS) after 18 hours of food deprivation by consuming RC until satiated in a first meal, refusing a second meal of rat chow, but consuming additional quantities of a more palatable food (Froot Loops, FL.)

Interesting questions:

1. How does daily access to a limited quantity of highly palatable food (FL) affect the patterns of food intake during a SSS experiment?

Possible outcomes and potential interpretations:
a. Rats with daily access to FL eat more than their "no access" counterparts.
........FL access promotes "binge eating."
........ novel foods stimulate excessive intake.
........ ?
b. Rats with daily access to FL eat less than their "no access" counterparts.
........Daily access to a highly palatable food results in "monotony"="boredom"=enhanced SSS
........?
c. Rats with daily access to FL eat the same as their "no access" counterparts.
........?

2a. What are the patterns of food intake following 18 hours of food deprivation when rats are offered a 1st meal (RC or FL) followed by a second meal (RC)? For each meal, cumulative food intake and latency to eat are measured.

2b. How does daily access to a limited quantity of highly palatable food (FL) affect the patterns of food intake in a two-course meal sequence (RC-RC, RC-FL, FL-RC)?

Template file for Research Poster (Powerpoint format)

Advice for creating a good poster