Electrode Tract Detection in the Brain
- Electrodes or injection are commonly made into the brain or spinal cord. Determining the locations is essential for the recording of brain electrical events and for injections of an experimental substance.
- The penetration into the brain or spinal cord by even the finest electrode or needle inadvertently nicks capillaries causes a small amount of blood to enter the parenchyma. The iron content of the red blood cells is soon released and remains in that location virtually permanently. Detection of the presence of the iron becomes an excellent means of revealing the tract and end points of electrodes and injection needles.In conjunction with the presence of the iron, the astrocytes in that locale are rendered in a persistent reactive state. Detection of this reactivity with staining with a GFAP antibody provides a means to cross check the iron date.
- Transcardial perfusion with fix and execution of the Perls reaction histochemical procedure (for ferric iron) ensures successful tract identification. Standard IHC methods for applying the GFAP antibody also allows for successful acquisition of data.