DEVELOPMENT OF SEX-DIFFERENCES IN THE BED NUCLEUS OF THE ACCESSORY OLFACTORY TRACT IN THE RAT

In the present study, we investigate the development of sex difference s in the bed nucleus of the accessory olfactory tract (BAOT), a sexual ly dimorphic structure in which masculinization of male rats depends o n the level of postnatal estradiol. Male and female Wistar rats were s acrificed postnatally when they were 1, 3, 7, 15, 45 and 60 days old, and stereological methods were used to estimate the volume and number of neurons in the BAOT of the subjects. With respect to volume, sex di fferences were established from P15. In relation to the number of neur ons, the males acquire their adult morphological parameter by P15, whi le females show a decrease (P3), increase (from P3 to P15) and later d ecrease (from P15 to P45). Sex differences from P3 to P7 might be rela ted to greater cell death in the BAOT of the females. These results su pport the hypothesis that both male and female rats reach their adult morphological pattern within this sexually dimorphic nucleus in an act ive manner. (C) 1998 Elsevier Science B.V. All rights reserved.