The anti-amnesic and neuroprotective effects of donepezil against amyloid 25-35 peptide-induced toxicity in mice involve an interaction with the 1 receptor agonist PRE-084 or the cholinesterase (ChE) inhibitors tacrine, rivastigmine and galantamine were administered either 20 min before behavioural sessions to check their anti-amnesic effects, or 20 min before A antagonist BD1047. Only PRE-084 and donepezil showed neuroprotection when administered pre i.c.v.; they blocked lipid peroxidation and learning deficits, effects inhibited by BD1047. Post i.c.v., PRE-084 and donepezil showed complete neuroprotection whereas the other ChE inhibitors showed partial effects. BD1047 blocked these effects of PRE-084, attenuated those of donepezil, but did not affect the partial effects of the other ChE inhibitors.., 2006). The apparatus consisted of an illuminated compartment with white polyvinylchloride walls (15 20 15cm high), a darkened compartment with black polyvinylchloride walls (15 20 15cm high) and a grid floor. A guillotine door separated each compartment. A 60W lamp positioned 40cm above the apparatus lit the white compartment during the experimental period. Scrambled foot shocks (0.3mA for 3s) were delivered to the grid floor using a shock generator scrambler (Lafayette Instruments, Lafayette, MA, USA). The guillotine door was initially closed during the training session. Each mouse was placed into the white compartment. After 5s, the door was raised. When the mouse entered the darkened compartment and placed all its paws on the grid floor, the door was gently closed and the scrambled foot shock was delivered for 3s. The step-through latency, that is, the latency spent to enter the dark compartment, and the number of vocalizations was recorded. The number of vocalizations did not differ between the groups, indicating that shock sensitivity was unaffected by the i.c.v. or i.p. treatments (data not shown). The retention test was carried out 24h after training.
