我国科学家成功破解了神经元“沉默突触”的沉默之谜，这类突触只有突触结构没有信息传递功能。如图所示的反射弧中具有“沉默突触”。其中—○—＜表示从树突到胞体，再到轴突及末梢。下列有关说法正确的是（）
A.若③为该反射弧的神经中枢，神经中枢内一定具有“沉默突触”
B.如果神经元内不能合成神经递质或者突触后膜缺乏相应受体，可能形成“沉默突触”
C.该反射弧的信息传导途径一定是①→②→③→④→⑤
D.若图中③为“沉默突触”，则刺激①不能引起e处的电位变化，同时⑤检测不到反应
参考答案：B
解析：③处可能有沉默突触，也可能没有，A错误；沉默突触没有信息传递功能，可能是没有神经递质，也可能是没有受体不能识别递质，B正确；反射弧的信息传导途径也可能是①→②→④→⑤，C错误；若③是沉默突触，信息可从②→④，所以刺激①，能引起e处电位变化，D错误。考点：本题考查反射弧相关知识，意在考查考生能从课外材料中获取相关的生物学信息，并能运用这些信息，结合所学知识解决相关的生物学问题。
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