Intracellular injection of lucifer yellow into cortical neurons in lightly fixed sections and its application to human autopsy material.

In this paper a method is described for injecting Lucifer yellow intracellularly in lightly fixed cortical slices. The resultant filling reveals detailed neuronal morphology of somata, dendrites, and their appendages offering the following advantages over currently available cell staining techniques: (1) a large number (10-30) of neurons can be filled intracellularly in a single experiment, (2) when coupled with retrograde fluorescent tracing methods, specific populations of neurons can be chosen for study, (3) good results can be obtained reliably, (4) neurons from autopsy or biopsy material can be intracellularly filled, (5) other neuronal features can be identified by combining this method with lectin or neurotransmitter immunocytochemistry, and (6) filled cells can be made electron dense, permitting specimens to be examined under the electron microscope.