Fig. 3.

Olfactory Detection Testing With and Without GABA(B) Antagonist. (A.) Mean (+/- S.D.) odor discrimination performance in young adult (open bar), aged learning-unimpaired (solid grey bar), and aged-learning impaired (hatched grey bar) in rats after injection with either saline (control condition) or 0.1 mg/kg CGP55845 (highest effective dose shown in Fig. 1) on discrimination problems prior to odor detection testing. The aged learning-impaired group performed significantly worse than both young and aged-unimpaired under the control condition (saline), an impairment that was once again reversed under 0.1mg/kg CGP 55845. (B.) After all rats reached criterion performance on the odor discrimination problems with saline or CGP55845, the rats were assessed for their ability to detect odors at decreasing dilutions. There were no differences between Cognitive Age Groups in their ability to detect an odorant at 1:10, 1:100, or even a 1:1000 dilution of the full strength odor.