title: The methodology for labeling the distal cerebrospinal fluid-contacting neurons in rats.
abstract: The distal cerebrospinal fluid-contacting neurons (dCSF-CNs) are one special type of neurons, whose bodies are in the parenchyma of the brain and processes extend into the ventricle, which suggested that dCSF-CNs might play the important roles in neuromodulation and neuroendocrinal regulation. Without special tracing method, the dCSF-CNs is hard to identify in parenchyma of the brain. Thus, up to present, these structure and function are seldom investigated. To explore dCSF-CNs, the cholera toxin subunit B conjugated with horseradish peroxidase (CB-HRP) as a tracer was injected into one of the rats' lateral ventricles, 48 h later following tracer injection rats were deeply anesthetized and fixed by intracardiac perfusion of 450 ml fixative at 25-30 ml/min. The brainstem were dissected out and stored in the fixative (postfix) for 4-6 h at 4 degrees C, then cryoprotected by immersion for 24-48 h in gradient sucrose (5%, 10%, 15%, 20%, and 30%) with 0.01 mol/l PBS at 4 degrees C. The brainstem segment was embedded, transverse or horizontal sections were cut with a cryostat and collected in phosphate-buffered saline (PBS). Three methodology were described to label the dCSF-CNs including tetramethylbenzidine-sodium tungstate (TMB-ST) method, CB-HRP-immunofluorescence procedures and CB-HRP-immunoelectron microscopic procedures.
authors.affiliation: Jiangsu Province Key Laboratory of Anaesthesiology, Xuzhou Medical College, Xuzhou, Jiangsu 221002, China.
authors.forename: Xianfu
authors.initials: X
authors.lastname: Lu
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Geng
authors.forename: Licai
authors.initials: L
authors.lastname: Zhang
authors.forename: Yinming
authors.initials: Y
authors.lastname: Zeng
mesh_terms: D000818:Animals; D001549:Benzamides; D001921:Brain / Q000033:anatomy & histology*; D002772:Cholera Toxin / Q000378:metabolism; D004805:Ependyma / Q000166:cytology*; D006735:Horseradish Peroxidase / Q000378:metabolism; D020547:Lateral Ventricles; D008297:Male; D009474:Neurons / Q000145:classification / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D001549:Benzamides; C031246:3,4,5-trimethoxybenzamide; D002772:Cholera Toxin; D006735:Horseradish Peroxidase