There is another form of the forced swimming test which is a better indicator of the development of "hopelessness". Rats are sequentially exposed to regular increases in forced swimming time until the next trial will be beyond their endurance. At that point they don't swim and "give up". If an antidepressant has an effect on such hopelessness, it will extend the number of trials before the rat gives up. As far as I know, the procedure calls for rescuing the rat. I forget the name of this procedure, if there is one, but I imagine this is what Wittenborn is referring to.
Bill Scott >>> David Epstein <[email protected]> 03/04/09 12:11 AM >>> On Tue, 3 Mar 2009, Mike Palij went: >> http://tinyurl.com/b5amaz > |Don told me that potential antidepressants were > |deemed worthy of trying out on people if a rat who had ingested them > |took longer to drown than a rat normally takes to drown when placed > |in a pool with no exit. To this day, this test is still used - only now to > |save time the rats are weighted. > I am sure that there are others on the list (e.g., David Epstein) who > can lay out the phases of drug testing and what the above test is > (is it the Morris water maze? > see: http://en.wikipedia.org/wiki/Morris_water_maze ). > But such details might detract from the writing's "punch". The Morris water maze is used in rodent studies of learning and memory. It's not exactly a maze, but as the term suggests, it does have a hidden platform on which the rodents can learn to perch once they find it. A different water test, called the forced-swimming test, is used as a behavioral assay for antidepressants. The major difference is that there's no hidden platform to learn about in the forced-swimming test. There's just...swimming. HOWEVER, I've never seen any reference to a forced-swimming test in which rodents were permitted to drown (or weighted down so they would do so!). In a brief Google Scholar search, I found that all references to drowning were in the context of specifying that the rodents were RESCUED if they seemed to be about to drown: <http://scholar.google.com/scholar?q=drown++forced+swimming+antidepressant> I didn't check all 1,290 hits, but I'll be (negatively) impressed if anyone finds one in which the rodents weren't rescued. --David Epstein [email protected] --- To make changes to your subscription contact: Bill Southerly ([email protected]) --- To make changes to your subscription contact: Bill Southerly ([email protected])
