Table 1. An overview of behavioral and neuromorphologcial features in the rat which are influenced by ovarian manipulations, with sex differences.* See text for details and references.
|
MEASURE | CHARACTERISTIC | SIGNIFICANT EFFECTS OF OVARIAN STEROIDS |
| Female Reproductive Behavior | ||
| Receptive (lordosis) | F more than M | Neonatal Ovx + T lowered scores more than neonatal T alone |
| Neonatal Ovx reduced scores more than postpuberal Ovx | ||
| "Proceptive (hopping, darting, ear wiggling) | F more than M | Neonatal Ovx reduced scores more than postpuberal Ovx |
| Neonatal Gdx combined with E or ovarian transplant raised scores more than
neonatal Gdx alone | ||
| Non-reproductive Behavior | ||
| Open-field activity | F higher than M | Neonatal Ovx reduced activity |
| Above restored by prepubertal low-dose E | ||
| Neonatal Ovx + T lowered scores more than neonatal T alone | ||
| Plus maze | F higher than M | Neonatal TX or pubertal Ovx decreased time in open arms; neonatal TX + Ovx
decreased time the most |
| Maze learning | F more errors than M | F errors increased after puberty |
| Neonatal low-dose E increased M errors | ||
| Active avoidance learning | F fewer errors than M | Sex difference appeared after puberty |
| Neonatal Ovx increased errors | ||
| Postpubertal Ovx decreased errors | ||
| Above reversed after 3 days of E | ||
| Performance varied across estrus cycle; high E levels | ||
| Increased errors | ||
| AMPH induced locomotion | F more active than M | Prepubertal Ovx decreases activity as compared to adult Ovx |
| Morphology | ||
| SDN-POA | F smaller than M | Neonatal TX to F reduced size, relative to control F |
| Neonatal E mRNA antisense reduced size, relative to control F | ||
| Postpubertal Gdx + E & P reduced size, relative to Gdx M | ||
| Gdx alone had no effect on M | ||
| AVPv | F larger than M | Sex difference emerged at puberty with increase in F |
| Postpubertal Gdx + E & P increased size, relative to Gdx M | ||
| Gdx alone had no effect on M | ||
| Dendritic spine density | ||
| Ventromedial hypothalamus | Varied across estrus cycle | Ovx reduced density; restored by low-dose E or E+P |
| Visual cortical pyramidal | After Day 20 M increased and F decreased | Day 30 Ovx prevented F-typical decrease in spines |
| Hippocampal pyramidal | Varied across estrus cycle | Ovx reduced density; restored by low-dose E&P |
| Dendritic branching | ||
| Parietal cortical pyramidal | TP F more arbor than F | Day 150 Ovx increased arbor in oil treated F |
| Cortical thickness | M, R>L; F no asymmetry or trend to L>R | Neonatal Ovx increased cortical thickness |
| Above reversed by E, days 40-90 | ||
| Above enhanced by P, days 40-90 |
*Exclusive of corpus callosum
F: females; M: males; Ovx: ovariectomy; Gdx: male castration; T: testosterone; E: estrogen; P: progesterone; TX: tamoxifen