ABSTRACT
Aim To observe the neuron nitric oxide synthase(nNOS) expression in the distal cerebrospinal fluid contacting neurons(CSF-CNs) of rat brain parenchyma, and investigate the role of CSF-CNs in the development of morphine dependence and withdrawal.Methods Male adult Sprague-Dawley rats, weighed 260?20 g,were experimented with A 3 ?l volume of 30% cholera toxin subunit B with horseradish peroxidase(CB-HRP) was injected into one of the rats′lateral ventricles to trace and locate the distal CSF-CNs of rat brain parenchyma 48 hours before the animals were killed. All animals were perfused and the relative tissue of rats′brain was removed.Frozen serial coronal sections (40 ?m) were cut. Then TMB-ST reaction procedure was used to stain the CB-HRP positive neurons,followed by immunohistochemistry double-labeling of the nNOS with CB-HRP positive neurons. The withdrawal symptoms were observed and scored. The numbers of the CB-HRP, and CB-HRP/nNOS positive neurons on the same segmental brain sections were counted.Results The withdrawal symptoms of the withdrawal group were significant, scores of all signs were significantly higher than those of the dependence groups and control group(P
ABSTRACT
Objective The ultrastructure of the distal CSF-contacting neurons in the dorsal raphe and the relationships with their surrounding tissues were observed and a new morphological evidence for their functional significance was offered. Methods We combined CB-HRP tracing with electron microscopic techniques and observed the ultrastructure of the distal CSF-contacting neurons in the dorsal raphe and the relationships with their surrounding tissues. Results 1.The CSF-contacting neurons have the general cytological structure of neurons; 2.CB-HRP mainly is localized in the trans face of the Golgi apparatus and lysosomes;3.There are two kinds of contrary direction synaptic relationships between the distal CSF-contacting neurons and the non-CSF-contacting neurons.Conclusions 1.There are no obvious differences between the CSF-contacting neurons and other neurons in ultrastructure;2.The Golgi apparatus and the lysosomes may exist the special function in take and transport the material from CSF;3.The CSF-contacting neurons can not only transport the material or deliver the information from the dorsal raphe to CSF,but also from CSF to the dorsal raphe.