Jenkins Trisha A, Latimer Mary P, Alderson Helen L, Winn Philip
School of Psychology, University of St. Andrews, Fife KY16 9JU, UK.
Neurosci Lett. 2002 Mar 29;322(1):45-8. doi: 10.1016/s0304-3940(02)00084-8.
The pedunculopontine tegmental nucleus (PPTg) contains cholinergic neurons whose principal ascending connections are with thalamic nuclei and structures associated with the striatum. It has been hypothesized that PPTg neurons are more closely associated with the substantia nigra (and therefore striatal motor systems) than with the ventral tegmental area (and therefore limbic striatal functions). In the present experiments we have examined the hypothesis that the PPTg is similarly associated with motor nuclei in the thalamus. Rats received unilateral ibotenate lesions of PPTg and were sacrificed 1, 2, 4 or 7 days later. Discrete thalamic nuclei, and samples of caudate-putamen and nucleus accumbens, were punched out and thalamic acetylcholine (ACh) and striatal ACh and dopamine (DA) content examined. Anteroventral nucleus had decreased ACh content after PPTg lesion, but a time dependent increase was found in mediodorsal nucleus; ACh concentration was unchanged in thalamic reticular nucleus or medial geniculate. No long-term lesion-dependent changes in striatal ACh or DA content were found. The effects of PPTg lesion on thalamic ACh content are consistent with the hypothesis that it has effects on motor nuclei, but also indicate that PPTg lesions have complex and dynamic effects on thalamic ACh content.
脚桥被盖核（PPTg）含有胆碱能神经元，其主要的上行连接是与丘脑核以及与纹状体相关的结构。据推测，PPTg神经元与黑质（以及因此与纹状体运动系统）的联系比与腹侧被盖区（以及因此与边缘纹状体功能）的联系更为紧密。在本实验中，我们检验了这样一种假说，即PPTg与丘脑的运动核也有类似的联系。给大鼠单侧注射鹅膏蕈氨酸损毁PPTg，并在1、2、4或7天后处死。取出离散的丘脑核以及尾状核-壳核和伏隔核的样本，检测丘脑乙酰胆碱（ACh）以及纹状体ACh和多巴胺（DA）的含量。PPTg损毁后，前腹核的ACh含量降低，但在背内侧核中发现了随时间而增加的情况；丘脑网状核或内侧膝状体中的ACh浓度未发生变化。未发现PPTg损毁对纹状体ACh或DA含量有长期的依赖性变化。PPTg损毁对丘脑ACh含量的影响与它对运动核有影响这一假说相符，但也表明PPTg损毁对丘脑ACh含量有复杂且动态的影响。
