Brain damage in the first week of life is behaviorally and anatomically devastating for a rat. I investigated the use of pre- and/or postnatal experience as interventions that might improve the outcomes in rats with postnatal day 4 (P4) frontal cortex lesions. Prenatal maternal tactile stimulation or maternal complex housing facilitated recovery in P4 lesion animals and produced changes in brain organization. Post-lesion tactile stimulation also was found to be beneficial possibly via experience dependent changes in FGF-2 expression. Levels of FGF-2 were increased in both skin and brain after tactile stimulation and correlated with behavioral and anatomical changes. Direct post-lesion administration of FGF-2 had similar effects. These results are the first demonstration that prenatal experience can be prophylactic for postnatal brain injury and that behavioral experience can act on brain organization via enhanced trophic factor expression originating in skin. / xxi, 221 leaves : ill. ; 28 cm.

This thesis examined the role of exogenous basic fibroblast growth factor (FGF-2) in stimulating recovery after early cortical injury. Rats with medial prefrontal cortex (MFC), posterior parietal cortex (PPC), or sham lesions at postnatal day 3 (P3) received one of three variations of FGF-2 treatment: postnatal FGF-2 that was either pre-mixed or prepared daily, or prenatal FGF-2, and tested in adulthood. Behavioral tests used were: 1) the Morris Water task and, 2) the Whishaw Tray Reaching task. The level of functional recovery attained was dependent on FGF-2 preparation and the developmental period. MFC lesion rats showed good recovery but there was a differntial effect of pre and postnatal FGF-2 that appeared to be related to task. PPC rats showed greater recovery after postnatal rather than prenatal treatment. Anatomical changes were restricted to groups with relatively good functional recovery. These findings suggest a multifunctional role of FGF-2 in the injured brain. / xvi, 223 leaves : ill. ; 29 cm.

Large neocortical lesions, such as hemidecortication, are detrimental for motor and cognitive skills. This thesis investigates the effect of age at the time of lesion on functional outcome. Attempts were then made to improve the outcome by using two simple treatments, tactile stimulation and Fibroblast Growth Factor-2 (FGF-2). The functional outcome of animals was measured using a series of behavioural tests (Morris water task, skilled reaching, forelimb placing during spontaneous vertical exploration, and the sunflower seed task). A qualitative difference was noted between animals that received hemidecortication at post natal day ten (P 10) versus animals that received a hemidecortication in adulthood (postnatal day, P 90). When the tactile stimulation treatment was used on animals that received P 10 hemidecortication, cognitive and motor improvements were noted. The same was not true for injections of FGF-2. When given after P 10 hemidecortication, this treatment impaired the cognitive abilities of rats in the Morris water task. There are two main points from this project: 1) overall functional recovery is not better or worse but simply different based on the age at which the trauma occurred and 2) treatments have varied success with different types of brain injury. / x, 123 leaves ; 29 cm.

This thesis examined how pharmacological treatment and cortical injury during development affects brain plasticity. Rats were given either a low dose of perinatal fluoxetine or a mild postnatal day 7 Hypoxic‐Ischemic (HI) injury, both, or neither. The functional outcome was assessed using a series of behavioral tasks and anatomical measures. To assess how HI affects the development of motor maps, forelimb motor maps were evoked at P19. The findings indicate that fluoxetine treatment or HI injury mostly negatively affected functional outcome. The combined treatment with fluoxetine and HI injury only interacted on a limited number of measures. There was no delay in the emergence of evoked motor movements, or change in map location in the HI animals. These results suggest that the pharmacological treatment and cortical injury described in this thesis may have different mechanisms whereby plastic changes are induced and the interaction between these two mechanisms is limited. / xii, 169 leaves : ill. ; 29 cm.