Abstract: Adult female rats were used and divided into two groups. The experimental rats were injec ted abdominally with pargiline and L-tryptophan which can promote the synthesis of 5HT, while inhibit the disintegration of it. The normal control rats were treated with nothing. The immunohistochemistry method was used to observe the distribution of 5HT nerve cells in brain and the fibres in pituitary and adrenal. It was found that the 5HT nerve cells can only be found in brainstem in the normal control group, while it can also be found in hypothalamus in the experimental group. The NE nerve cells were distributed in septal area, hypothalamus and brainstem. In pituitany intermediate lobe and neuroal lobe, can be found the fibres of 5HT and NE. Lots of 5HT and NE cell can be found in adrenal.

Key words: 5HT cell, NE cell, immunohistochemistry