Fig 4. Genital cortex growth in prepubescent females is accelerated by tactile cues from males.

(A) Prepubescent animals (postnatal day [P]21) were cohoused for 9 days with either an adult, sexually experienced female (upper panel) or a sexually experienced adult male (middle panel). Whereas tactile contact was allowed in both of these groups, the third group of prepubescent rats was only exposed to olfactory (by a daily exchange of bedding between the cage compartments), visual, and auditory cues of a sexually experienced adult male (lower panel). (B) Upper panel: Outline of a somatosensory cortex (S1) map from the brain of a P30 female cohoused with a sexually experienced adult female. Genital cortex is labeled in black. Middle panel: Map from a brain of a P30 female cohoused with a sexually experienced adult male. Lower panel: Outline of a S1 map obtained from a P30 female exposed to olfactory, visual, and auditory cues but not tactile cues from a sexually experienced adult male. (C) Absolute area of genital cortex in hemispheres of P30 females cohoused with either a female (female and contact), a male (male and contact), or with a male without having tactile contact (male and no contact). Note that the size of genital cortex in the brains of animals who were cohoused in tactile contact with a male is significantly larger compared to the other 2 groups (female and contact, and male and no contact). (D) Same as (C), but the fraction of genital cortex of the entire S1 is shown. (E) Same as (C), but the absolute area of S1 is plotted. There is no difference between the 3 groups. See also S1 Data.