Gelatin embedding to preserve lesion-damaged hypothalami and intracerebroventricular grafts for vibratome slicing and immunocytochemistry.

Vibratome sectioning of paraformaldehyde-fixed brains containing a lesion and/or intracerebroventricular grafts and staining of these sections often lead to damage around the site of the lesion and loss of the implants. Various embedding procedures were compared in order to find a method to overcome this problem. The best results were obtained when fixed brain tissue was first embedded under reduced pressure in 10% gelatin at 50 degrees C, and then fixed again, in 4% paraformaldehyde. The method did not affect the immunocytochemical staining for vasopressin, vasoactive intestinal polypeptide, somatostatin, gonadotropin releasing hormone and neuropeptide Y.