Morphological, immunohistochemical and quantitative studies of murine brain mast cells after mating

The mast cell is one of the immune cells, and can be triggered behaviorally to increase in the CNS of the sexually active dove. In the present study, we used ICR mice to investigate the number of brain mast cells in mated (on e male with three female mice), non-mated (housed with female mice, but no mating) and control (four male mice housed together in one cage) male mice. We found that at least 40% of mated male mice had significant more mast ce lls than the maximum value seen in the controls, and that a significant cor relation existed between the distribution index of mast cells and the postc oitum date. These mast cells were especially numerous in the thalamus and v elum interpositum (VIP). Morphological observations showed that the increas ed mast cells were ultrastructurally similar to those in the controls, and displayed gonadotropin-releasing hormone (GnRH)-like immunoreactivity. Base d on the facts that the number of brain mast cells in the male mice increas ed significantly after mating and that the change in the distribution of ma st cells in the VIP and the thalamic parenchyma correlated well with time p ostcoitum, we speculate that, after mating, mast cells may migrate from the VIP to the thalamic parenchyma along the vascular tree of the brain. These results strongly suggest that mast cells are involved in the interaction a mong the immune, endocrine, and nervous systems in the mated male mouse bra in. (C) 1999 Elsevier Science B.V. All rights reserved.