Noradrenergic and peptidergic innervation of the mouse femur bone marrow

The innervation of bone marrow from femur bones of BALB/c mice was studied by means of immunohistochemistry and fluorescence histochemistry. The immunoperoxidase method with nickel amplification was applied to visualize the topographical distribution of nerve fibers using antibodies against the general neuronal marker PGP 9.5 (neuron-specific cytoplasmic protein), catecholamine synthesizing enzyme tyrosine hydroxylase (TH) and neuropeptide Y (NPY). Glyoxylic acid-induced fluorescence was also applied to demonstrate catecholamine-containing nerves. Both staining methods revealed dense innervation by fibers seen predominantly around blood vessels but also ramifying among marrow cells. Recent findings on adrenergic and peptidergic influences on marrow physiology combined with anatomical data indicate the existence of a neural modulation of hematopoiesis.