Olfactory discrimination learning in mice lacking the fragile X mental retardation protein.

An automated training system was used to compare the behavior of knockout (KO) mice lacking the fragile X mental retardation protein with that of wild-type (WT) mice (C57Bl/6 strain) in the acquisition and retention of olfactory discriminations. KO and WT mice did not differ in the acquisition of a four-stage nose poke shaping procedure. In two separate experiments, mutant mice required substantially more training to acquire a series of novel olfactory discrimination problems than did control mice.

Impaired olfactory discrimination learning and decreased olfactory sensitivity in aged C57Bl/6 mice.

Young (4 months) and old (24 months) C57Bl/6J mice were tested in an automated simultaneous-cue, two-odor discrimination task. The mice were first pre-trained to execute trial-structured nose poke responses in a straight alley. They were then trained to criterion on a series of eight novel olfactory discrimination problems.