Payne J N, Peace J M
Department of Biomedical Science, Sheffield University, U.K.
Exp Brain Res. 1989;75(1):169-82. doi: 10.1007/BF00248540.
The retrograde tracers true blue and diamidino yellow were injected into the caudate-putamen of adult rats which were allowed to survive for periods of 12 to 480 h after these injections. The retrograde axonal transport of these tracers was assessed by microphotometric measurement of the intensity of fluorescence in labelled neurones in the following three different sources of afferents to the caudate-putamen: the substantia nigra pars compacta; the parafascicular nucleus; and the dorsal raphe nucleus. It took respectively 12, 24 and 48 h for neurones in the substantia nigra, parafascicular nucleus and dorsal raphe nucleus to become retrogradely labelled. The average fluorescent intensity was greatest after 96-168 h but this highest value, and the subsequent decline, in fluorescence varied considerably between different tracers and different pathways. Neither axonal length nor neuronal activity correlate well with dynamics of build up and decline in fluorescence, but axonal collateralisation and diffuseness of terminals are associated with slower accumulation and more rapid removal of the tracers. Some neurones labelled with true blue retain their fluorescence better than those labelled with diamidino yellow but these differences are overshadowed by differences between different pathways in this respect.
将逆行示踪剂真蓝和双脒基黄注入成年大鼠的尾状核-壳核，注射后让大鼠存活12至480小时。通过显微光度测量尾状核-壳核以下三种不同传入源中标记神经元的荧光强度，评估这些示踪剂的逆行轴突运输：黑质致密部、束旁核和中缝背核。黑质、束旁核和中缝背核中的神经元分别需要12、24和48小时才能被逆行标记。平均荧光强度在96 - 168小时后最大，但这种荧光的最高值及其随后的下降在不同示踪剂和不同通路之间有很大差异。轴突长度和神经元活动与荧光积累和下降的动态变化均无良好相关性，但轴突侧支化和终末扩散与示踪剂积累较慢和清除较快有关。一些用真蓝标记的神经元比用双脒基黄标记的神经元保留荧光更好，但在这方面不同通路之间的差异掩盖了这些差异。
