The participation of mast cells and serotonin-immunoreactive fibers in the innervation of the cerebral vessels

Interrelations between adrenergic and serotoninergic nerve fibres and mast cells located near the vascular wall were studied on total preparations of rat brain pia mater. Histochemical method with glyoxylic acid revealed the dense network of adrenergic fibres and their terminal regions with variceal endings with mast cells located next to them. Immunohistochemical methods (fluorescent and method with use of peroxidase antiperoxidase complex) with the aid of antiserum serotonin showed the content of serotonin in these cells. Distribution of serotoninergic nerve fibres resemble that of adrenergic fibres with density being significantly lower. The fibres have frequent contacts with mast cells processes. These data indicate the presence of functional connection between serotonin positive nerve fibres and the possibility of their drawings in control of blood circulation of brain.