Changes in the neonatal gonadal hormonal environment prevent behavioral sparing and alter cortical morphogenesis after early frontal cortex lesions in male and female rats.
The effects of perinatal exposure to testicular hormones were studied in male and female rats given medial prefrontal lesions (PFC) on Postnatal Day 7. Hormonally intact rats with PFC lesions showed recovery of performance of the Morris water task but no recovery on a forelimb reaching task. Recovery was abolished in both males gonadectomized at birth and in females given testosterone at birth. Male rats with PFC lesions showed an increase in pyramidal cell spine density. This was blocked in gonadectomized animals. In contrast, female rats with PFC lesions showed an increase in dendritic arbor. This was reduced by perinatal testosterone. Interference with the gonadal hormonal environment reduced the brain's ability to compensate for the effects of early cortical lesions.
Kolb
B
B
Department of Psychology, University of Lethbridge, Alberta, Canada.
Stewart
J
J
D000818:Animals; D000831:Animals, Newborn; D001070:Appetitive Behavior / Q000187:drug effects / Q000502:physiology; D001931:Brain Mapping; D002452:Cell Count / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D003712:Dendrites / Q000187:drug effects / Q000502:physiology; D004924:Escape Reaction / Q000187:drug effects / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000187:drug effects* / Q000502:physiology; D005865:Gestational Age; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology; D009024:Morphogenesis / Q000187:drug effects* / Q000502:physiology; D009416:Nerve Regeneration / Q000187:drug effects* / Q000502:physiology; D009473:Neuronal Plasticity / Q000187:drug effects* / Q000502:physiology; D009949:Orientation / Q000187:drug effects / Q000502:physiology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology; D051381:Rats; D012733:Sex Differentiation / Q000187:drug effects*