We have previously shown that the continuous intracerebroventricular infusion of beta-amyloid(1-40) protein results in memory impairments in rats, associated with a reduction of choline acetyltransferase activity in the frontal cortex and hippocampus. In the present study, we examined whether the infusion of beta-amyloid(1-40) protein affected the content of ciliary neurotrophic factor (CNTF) in the rat brain. The beta-amyloid(1-40) infusion increased CNTF content in the frontal cortex, hippocampus, and the cerebellum, but decreased its content in the brain stem. These results suggest that accumulation of beta-amyloid(1-40) in the brain may affect CNTF production in vivo.