Abstract: To investigate the effect of NGF on neurons in the dorsal root ganglion(DRG)after a injury of peripheral nerves, a unilateral transaction of the branchial plexus was done in six rabbits with the age of one month. After the transaction, 25 μg NGF was given to the stump end of the nerves before they were sutured and all animals were kept alive for one month. During this period, the rabbits were intramuscularly injected with 12.5 μg NGF every other day. The sizes of the cell bodies and nucleoli and numbers of neurons in the DRG were observed and counted under a light microscope. The ratio of the cell numbers between the injured side and uninjured side were quite close to one in the six rabbits. The nucleoli were taken as a index of calculation of cell numbers. The image analysis was used to measure the sizes of cells and nucleoli in one rabbit. The statistic analysis were used to make comparison of data from different segments and we found that there was no remarkable difference with regard to average diameter of the cells between the injured and uninjured side(P>0.05). There was noremarkable difference on the average diameter of the nucleoli between the two sides either(P>0.05).

Key words: cell number counting|NGF|dorsal root ganglion|branchial plexus transaction