Cirelli C, Fung S J, Liu R H, Pompeiano O, Barnes C D
Dipartimento di Fisiologia e Biochimica, Università degli Studi di Pisa, Italy.
Arch Ital Biol. 1998 Nov;136(4):257-71.
Although the whole cerebellar cortex receives cholinergic afferents, the source of origin of this projection has been clarified only for some corticocerebellar regions. Experiments were performed in kittens to investigate whether the two major cholinergic groups of the brainstem, the pedunculopontine (PPT) and laterodorsal tegmental nuclei (LDT), contribute to the cholinergic innervation of the cerebellar cortex, in particular the vermal cortex. Tegmento-cerebellar projecting neurons were identified by injecting the retrograde tracer rhodamine-labeled latex microspheres in the lobules V to VII of the cerebellar vermis. Subsequently, some of these tegmento-cerebellar neurons were demonstrated to be cholinergic by using the immunohistochemical technique for choline acetyltransferase (ChAT). Only a small portion of the ChAT-positive tegmental neurons projected to the cerebellar vermis. However, among the whole population of the retrogradely labeled tegmental neurons about one third were cholinergic. These cholinergic tegmento-cerebellar neurons were located in the PPT, LDT, and also within the locus coeruleus (LC) complex, where noradrenergic neurons predominate. Since the LC complex sends noradrenergic afferents to the cerebellar cortex, it appears that the dorsal pontine area contributes to the tegmento-cerebellar projections not only with noradrenergic but also with cholinergic afferents. The physiological significance of this cholinergic projection to the cerebellar cortex has been discussed.
虽然整个小脑皮质都接受胆碱能传入纤维，但仅对某些皮质小脑区域明确了该投射的起源部位。在幼猫身上进行了实验，以研究脑干的两个主要胆碱能神经元群，即脚桥核（PPT）和脑桥背外侧被盖核（LDT）是否参与小脑皮质，特别是小脑蚓部皮质的胆碱能神经支配。通过将逆行示踪剂罗丹明标记的乳胶微球注射到小脑蚓部的V至VII小叶中来识别被盖 - 小脑投射神经元。随后，通过使用胆碱乙酰转移酶（ChAT）的免疫组织化学技术证明这些被盖 - 小脑神经元中的一些是胆碱能的。只有一小部分ChAT阳性的被盖神经元投射到小脑蚓部。然而，在整个逆行标记的被盖神经元群体中，约三分之一是胆碱能的。这些胆碱能的被盖 - 小脑神经元位于PPT、LDT以及蓝斑（LC）复合体中，其中去甲肾上腺素能神经元占主导。由于LC复合体向小脑皮质发送去甲肾上腺素能传入纤维，看来脑桥背侧区域不仅通过去甲肾上腺素能传入纤维，还通过胆碱能传入纤维参与被盖 - 小脑投射。已经讨论了这种向小脑皮质的胆碱能投射的生理意义。
