Smythe J W, Bhatnagar S, Murphy D, Timothy C, Costall B
Postgraduate Studies in Neuropharmacology, Department of Pharmacology, University of Bradford, UK.
Brain Res Bull. 1998;45(1):89-93. doi: 10.1016/s0361-9230(97)00311-0.
Hippocampal cholinergic projections mediate attention to arousing stimuli as demonstrated by behavioral, electrophysiological, and endocrine studies. We recently reported that peripheral injections of the cholinergic antagonist scopolamine (SCOP) increased anxiety-like behaviour (ALB) in rats and we sought to investigate if this response might be hippocampally mediated. Adult male, Lister Hooded rats were implanted bilaterally with hippocampal cannulae 3 weeks prior to testing. On the test day, rats were injected with vehicle (VEH; artificial CSF at 3 microl), 15 or 30 microg SCOP, 20 min prior to being placed into the white chamber of the black-white box (n = 10/group). Rats were scored for latencies to exit and reenter the white chamber, total time spent in the white chamber, intercompartmental crossings, and activity. SCOP at 30 microg significantly reduced time to exit the white arena, while both doses of SCOP elevated latencies to reenter the white chamber. There were no effects of SCOP on intercompartmental crossing, time spent in the white chamber, or on activity levels. Loss of hippocampal cholinergic function impairs processing of threatening stimuli that manifests itself as increased ALB.
行为学、电生理学和内分泌学研究表明，海马胆碱能投射介导对唤起刺激的注意力。我们最近报道，外周注射胆碱能拮抗剂东莨菪碱（SCOP）会增加大鼠的焦虑样行为（ALB），我们试图研究这种反应是否可能由海马介导。成年雄性利斯特戴帽大鼠在测试前3周双侧植入海马套管。在测试当天，大鼠在被放入黑白箱的白色箱室前20分钟，注射溶剂（VEH；3微升人工脑脊液）、15或30微克SCOP（每组n = 10）。记录大鼠离开和重新进入白色箱室的潜伏期、在白色箱室中花费的总时间、隔间间穿越次数和活动情况。30微克的SCOP显著缩短了离开白色区域的时间，而两种剂量的SCOP都延长了重新进入白色箱室的潜伏期。SCOP对隔间间穿越、在白色箱室中花费的时间或活动水平没有影响。海马胆碱能功能丧失会损害对威胁性刺激的处理，表现为ALB增加。
