Hi everyone, happy new year. Alison and Gwen thanks for reviving this question. I did continue to tinker with modifications for a rat
adaptation that I mentioned early on in this same thread a couple years
ago. I eventually had a complete redesign of the whole device (on paper,
at least) that moves away from a 3-d printed housing for the sake of
physical robustness against rats, instead mounting the electronics into
standard sized electrical junction boxes (
for example). The design would have had a steel face plate custom laser-cut by
SendCutSend*,
with a 3d printed pellet well/dispenser assembly mounted
on top of the metal box through one of the pre-punched cutouts. The aim
was for DIY assembly (since I was always enamored with Lex's original
approach of designing something any lab could build with mostly
off-the-shelf parts). I stopped when I reached the point the best next
step would be to modify the physical layout of the circuit board, and
when paused at that point, I then learned (
and this is probably the answer to your actual question...) from Claire Foldi at Monash that she and her group
have had good success using the current mouse FED3 device for rats.
Specifically, females SD rats up to ~15 weeks old, I believe she said. A few caveats: #1, the standard FED3 can
only accommodate 20mg pellets, not the 45 mg pellets more commonly used
with rats, and Claire said they do use 20mg and rats actually learn
quickly and you get a lot of behavior for the 20mg pellets because rats
are not getting quickly satiated. #2, at the start, baiting the nose
poke wells with sucrose pellets helps them learn the task. #3 very
important is to glue metal washers (
this is a good size)
on the front of the nose-poke ports to deter rats from chewing up the
plastic face (you also want the nose piece that the pellet drops into
printed in brass or other metal).
I don't
want to speak for Claire (who I think may be in this group) but I can
confirm I assembled one recently and tested it with a couple young adult
female rats (9-10 weeks old, ~200 g) successfully.
*tangentially-
just a plug from a satisfied customer. If you ever need laser cut metal
parts or very large acrylic parts I've been thrilled with SendCutSend. I
had a Barnes maze top and a few other small pieces made and the prices
and customer service are amazing. If you need a few metal parts laser
cut they can often make it for less $ than the typical retail price
you'd pay yourself just for the the materials. I don't know how they
manage that but I'm willing to believe there's magic involved.