Svedberg_2004_Neuropharmacol_47_558

Overexpression of acetylcholinesterase (AChE) in mice causes cholinergic deficits with memory impairment. In this study, AChE overexpressing (hAChE-Tg) and control (FVB/N) mice were treated with the AChE inhibitor (AChEI) galantamine (4 mg/kg/day) for 10 days. The concentration of galantamine in plasma was 75-80 ng/ml. The inhibition of AChE was 20% in red blood cells (RBC) and 30% in brain cortical tissue. A significant increase in [(3)H]cytisine (alpha4 nicotinic receptor) binding was measured in the CA1 and CA3 area of the hippocampus of FVB/N mice following galantamine treatment. Similarly, a significant increase in [(125)I]alphabungarotoxin (alpha7 nicotinic receptor) binding was found in the frontal cortex, retrosplenial gr. cortex, motor cortex and thalamus in galantamine treated FVB/N compared to saline treated mice. No significant changes in nicotinic receptor binding sites were observed in galantamine treated hAChE-Tg mice. Significant decreases in the muscarinic receptors measured by [(3)H]AF-DX-384 (M2 muscarinic receptor) and [(3)H]pirenzepine (M1 muscarinic receptor) were observed in several brain regions of galantamine treated FVB/N and hAChE-Tg mice. This study shows regional and receptor subtype specific changes in the nicotinic receptor subtypes compared to the muscarinic receptors following galantamine treatment in FVB/N and hAChE-Tg mice.