The Cerebral Perivascular Cells

by Doychin N. Angelov, Michael Walther (Editor), Michael Streppel (Editor)

1 Introduction.- 1.1 Antigen Presentation and Antigen Presenting Cells.- 1.2 Antigen Presentation within the CNS.- 1.3 Microglia Might Be the Cerebral Antigen Presenting Cells.- 1.4 Theories on the Antigen Presentation Site.- 1.5 Questions Still Open.- 1.6 Methodological Approach.- 2 Materials and Methods.- 2.1 Animals.- 2.2 Overview of Animal Experiments.- 2.3 Surgery.- 2.4 Number of Sprouting Neurons After Retrograde Tracing with HRP.- 2.5 Number of Surviving Neurons After Resection of the Facial Nerve.- 2.6 Neuronophagic Microglia Identified by Vital Labeling with Fluoro-Gold.- 3 Results.- 3.1 Resection of 10 mm of the Facial Nerve Causes a Slow Loss of Facial Motoneurons in the Adult Rat.- 3.1.1 Comparison of Axonal Sprouting After Transection and Resection of the Facial Nerve as Revealed by Retrograde Tracing with Horseradish Peroxidase.- 3.1.2 Comparison of Neuron Numbers in the Facial Nucleus After Transection and Resection of the Facial Nerve as Revealed by Immunocytochemistry with Anti-NSE.- 3.2 No Breakdown of the Blood - Brain Barrier or Passage of Unprimed Lymphocytes into Brain Tissue After Facial Nerve Resection.- 3.2.1 Intact Blood - Brain Barrier to HRP After Resection of the Facial Nerve.- 3.2.2 No Entry of Lymphocytes into the Brain Tissue After Resection of the Facial Nerve.- 3.2.3 No Immunopositive Cells for "Lymphocyte-Recognizing" Antibodies Observed in the Lesioned Facial Nucleus.- 3.3 Fluoro-Gold Labeling of Motoneurons, Phagocytic Microglia and Perivascular Cells.- 3.3.1 Injection of Fluoro-Gold 29 into the Whiskerpad Muscles.- 3.3.2 Intravenous Injection of Fluoro-Gold.- 3.3.3 Intracerebroventricular Injection of Fluoro-Gold.- 3.4 Time Course of Existence and Migration of Fluoro-Gold-Labeled Neuronophages.- 3.4.1 Quantitative Estimates on the Neuronofugal Migration of Phagocytic Microglia as Identified by Fluoro-Gold.- 3.4.2 Migration of FG-Labeled Neuronophages.- 3.5 Immunocytochemistry of the Fluoro-Gold-Labeled Neuronophages.- 3.5.1 Bright-Field Immunohistochemistry.- 3.5.2 Combination of Immunohistochemistry with Fluoro-Gold Labeling.- 4 Discussion.- 4.1 Oligodendrocytes and Astrocytes Are Not the APC of the Brain.- 4.2 Microglia Are Not the APC of the Brain.- 4.2.1 Phagocytic Microglia Either Return to a Resting State or Die Due to Apoptosis.- 4.2.2 No Contact Between Phagocytic Microglia and Lymphocytes Beyond the Intact Blood - Brain Barrier of the Lesioned Facial Nucleus.- 4.2.3 Phagocytic Microglia Do Not Reach the Perivascular Space of the Brain.- 4.3 The Perivascular Cells Are the APC of the Brain.- 4.3.1 Sequential Immunoquenching Reveals That ED2-Positive Perivascular Cells Can Act as Neuronophages.- 5 Summary.- References.

104 pages, Paperback

First published September 21, 1998