Methods

Abstract

The first intravital microscopic observations were reported by Leeuwenhoek, the inventor of the microscope. Examination of the brain surface dates back to the 19th Century, in the publications of Ravina (1811) and Donders (1850) ⁷². The first systematic intravitalmicroscopic investigations were begun in the second decade of our century. In 1925, Heimberger ¹³³ studied the capillary bed in human skin with a simple microscope and carbon light source and gave the first important report on capillary reactions to localized trauma. Landis ¹⁸² and Forbes ¹⁰⁷, using similar instruments, first observed and described frog mesentery using a “Photomikroskopisches Okular” from Zeiss. Wolff and Fog used normal microscopes without adaptation, as phototechnical possibilities were very restricted. Quantitative evaluation had to be performed by directly observing the object because suitable light sources for photo-documentation at higher magnifications did not exist. The “bright-field-opaqueilluminator” optic, described in 1923 by Vonwiller ²⁸⁰ was not able to improve conditions for intravital, direct-light microscopy and this system was rarely used. In 1932, Heine ¹³⁴ with his dark-groundilluminator created the basis of the modern “ultropak” system. The next important step was probably the development of a high-pressure mercury lamp (Gottschewski ¹²¹).