Court J A, Ballard C G, Piggott M A, Johnson M, O'Brien J T, Holmes C, Cairns N, Lantos P, Perry R H, Jaros E, Perry E K
Joint MRC-University of Newcastle Centre Development in Clinical Brain Ageing, MRC Building, Newcastle General Hospital, Westgate Road, Newcastle-upon-Tyne NE4 6BE, UK.
Pharmacol Biochem Behav. 2001 Dec;70(4):571-9. doi: 10.1016/s0091-3057(01)00644-x.
Patients with dementia with Lewy bodies (DLB) commonly experience psychotic symptoms, most notably visual hallucinations. Previously, it has been shown that visual hallucinations in DLB are associated with reduced cortical choline acetyltransferase activity, a marker of cholinergic innervation, but not with predominantly postsynaptic muscarinic M1 receptor binding. In the present investigation, nicotinic acetylcholine receptor (nAChR) levels in the temporal cortex (Brodmann's areas [BA] 20 and 36) were measured in a group of 24 prospectively assessed DLB patients; comparisons were made between groups with or without visual and auditory hallucinations and delusional misidentification. Visual hallucinations and delusional misidentification were associated with lower [(125)I]alpha bungarotoxin binding in areas 36 and 20 (P<.05), but not with changes in [(3)H]epibatidine binding. There were no significant associations with auditory hallucinations. [(3)H]epibatidine, but not [(125)I]alpha bungarotoxin, binding for all DLB cases was reduced compared to controls (P<.001). Loss of cortical alpha 7 nicotinic receptors may contribute to hallucinations and delusional misidentification in DLB, with implications for treatment and understanding the mechanisms of psychotic symptoms in dementia.
路易体痴呆（DLB）患者常出现精神症状，最显著的是视幻觉。此前研究表明，DLB中的视幻觉与皮质胆碱乙酰转移酶活性降低有关，皮质胆碱乙酰转移酶活性是胆碱能神经支配的标志物，但与主要的突触后毒蕈碱M1受体结合无关。在本研究中，对一组24例经前瞻性评估的DLB患者测量了颞叶皮质（布罗德曼区[BA]20和36）中的烟碱型乙酰胆碱受体（nAChR）水平；对有或无视幻觉、听幻觉及妄想性错认的患者组进行了比较。视幻觉和妄想性错认与36区和20区较低的[（125）I]α - 银环蛇毒素结合有关（P<0.05），但与[（3）H]依博加碱结合的变化无关。听幻觉无显著相关性。与对照组相比，所有DLB病例的[（3）H]依博加碱结合减少，但[（125）I]α - 银环蛇毒素结合未减少（P<0.001）。皮质α7烟碱型受体的丧失可能导致DLB中的幻觉和妄想性错认，这对治疗及理解痴呆中精神症状的机制具有重要意义。
