Belladonna alkaloids-induced behavioral changes and amnesia on open-field and step-through in 18-,28-, and38-day-old mice

目的：比较阿托品（Ａｔｒ），东莨菪碱（Ｓｃｏ），樟柳碱（ＡＴ３）和山莨菪碱（Ａｎｉ）对小鼠行为及记忆损伤作用．方法：行为和记忆实验用开阔和回避反应法．脑Ｍ受体用［３Ｈ］ＱＮＢ测定．结果：Ａｔｒ，Ｓｃｏ和ＡＴ３增加小鼠走动行为２６％－４２％，降低站立，修饰，排便行为５０％－１００％，并抑制开阔记忆．４个药物均能妨碍回避反应．小鼠１８日龄额叶皮层和海马［３Ｈ］ＱＮＢ结合位点数少于３８日龄７％－２３％．结论：１）莨菪类生物碱对小鼠行为和记忆障碍的作用随其日龄增加而减弱．２）Ｓｃｏ对幼年小鼠的行为及记忆障碍作用的最小有效量分别是Ａｔｒ，ＡＴ３和Ａｎｉ的１／１０，１／１００和１／１０００．

AIM: To study the agerelated changes of atropine (Atr), scopolamine (Sco), anisodine (AT3), and anisodamine (Ani) on behaviors and memories. METHODS: The behaviors and memories were measured with openfield test and stepthrough task. Mcholinergic receptors were determined by quinuclidinyl benzilate (QNB). RESULTS: During acquisition session (d 1) the 18, 28, and 38dold mice pretreated with Atr, Sco, and AT3 (002, 02, 2, or 20 mg·kg-1, ip) in openfield test showed increase in walking counts by 26 %-42 %, but decrease in rearing, grooming, and defecating counts for 50 %-92 %, 67 %-100 %, and 75 %-100 %, respectively. On recall session (d 2) the walking and rearing behaviors in the 18 and 28dold mice receiving Atr, Sco, and AT3 on d 1 were higher than those in the mice receiving saline. But a lower grooming behavior on d 2 was found in the mice receiving the drugs on d 1. On d 1 Ani 20 mg·kg-1 reduced the rearing behavior by 50 % in 18dold mice and defecation by 33 %-36 % in 18 and 28dold mice. All the 4 belladonna alkaloids increased the number of avoidanceresponse errors and decreased the retention latencies in stepthrough task. Bmax of QNB binding sites in frontal cortex and hippocampus regions in the 38dold mice increased 7 % and 23 % vs in the mice of 18 d of age, respectively. CONCLUSION: 1) The effects of the belladonna alkaloids on behaviors and memories in adult mice were weaker than those in young mice. 2) The belladonna alkaloidsinduced amnesia on passive avoidanceresponse in stepthrough was more sensitive than behavioral changes and amnesia on openfield. 3) According to the lowest effective doses which insulted the behaviors or memories in young mice, Sco was about 10, 100, and 1000 times more potent than Atr, AT3, and Ani, respectively.