MOUSE :: HMDP :: Attention-related behavioral traits

K.         Hybrid Mouse Diversity Panel:  Attention-related behavioral traits

1.         Mice (D. Jentsch)
2.         Phenotyping (D. Jentsch)
3.         Brain MRI (S. Tetradis)

 

1.         Mice (D. Jentsch)

Adult male mice (2-6 mice per strain) sampled from common and recombinant inbred strains recommended for the Hybrid Mapping Diversity Panel were acquired from three sources: Jackson Labs, University of Tenn. Health Science Center (BXD strains only; R. W. Willians), and UCLA (A. L. Lusis, et al.). Subjects were habituated to the testing facility for approximately two weeks after importation, group-housed by strain in standard cages on a 14/10 light/dark schedule, initially with food and water ad libitum. Mean age at onset of training was approximately 105 days. Data from the BXD mice included in this study were published previously[1].  Three to five days prior to the onset of training, mice received restricted access to food in their home cage, sufficient to achieve a ~10-15% decline of their free-feeding weights, adjusted to a maximum of 20% decline during testing.
Procedures were consistent with the Public Health Service’s Guide for the Care and Use of Laboratory Animals and were approved by the Chancellor’s Animal Research Committee at UCLA.

 


2.         Phenotyping (D. Jentsch)

Mice were trained and tested daily in individual Med Associates (St Albans, VT) operant conditioning chambers fitted with a horizontal array of 5 nose poke apertures on one side of the box and a photocell-equipped food-delivery magazine on the other. The subjects were trained to initiate trials by nose poking into the central aperture, triggering illumination of flanking apertures. Responding in one of the two illuminated apertures was reinforced (1 food pellet; termed a correct response), while responses at the other aperture earned a time-out (all lights extinguished for 5 seconds; termed an incorrect response). The aperture reinforced during initial training was randomized across subjects and strains. All animals were tested in daily sessions that ended after: 1) one hour, 2) 126 trials, or 3) the performance criterion (16 out of 20 correctly-completed trials, computed as a moving window) was reached. Once a performance criterion was met within a session, testing on that day was stopped and the reinforcement contingencies were reversed beginning in the following session. All mice completed the initial 2-choice discrimination acquisition phase and one reversal phase.

The primary measures were trials to criterion during the 2-choice discrimination acquisition and the reversal learning phases. Additional incidental measures were also recorded, including average latency to initiate trials, average latency to make a correct response, average latency to retrieve the food reward, and anticipatory nose pokes, tracked separately during both the acquisition and reversal learning phases. Measured phenotypes were analyzed for genetic association using the Efficient Mixed Model Association algorithm, implemented online at http://mouse.cs.ucla.edu/emmaserver/.

Laughlin, R.E., et al., Genetic dissection of behavioral flexibility: reversal learning in mice. Biol Psychiatry, 2011. 69(11): p. 1109-16.

 


3.         Brain MRI (S. Tetradis)

In development.