LAY ABSTRACT IBN-9814387 SGER: Enrichment-induced Plasticity in Neonatal Whisker Somatosensory Cortex The importance of enrichment during early development on brain and behavioral experience-dependent plasticity is clearly documented. A theme, which appears to be emerging from studies of early development is that the emotional context of the stimuli, has an enormous impact on behavioral and brain changes, especially during early development. Thus, these emotional events can guide behavioral and neural development, which result in permanent alterations in these systems. The objective of the proposed experiment is to do assess whether the relevance or significance of stimuli can also have a strong impact on experience dependent behavioral and neural changes. The whisker system in rats offers an excellent system for studying information processing because the somatosensory cortex is a relatively well understood network of neurons and the neural pathway between the whiskers and the cortex has been thoroughly described. Furthermore, each whisker is represented by a cortical neural network called a "barrel" which is easily identifiable with histological staining. During the neonatal period, when a whisker is removed, its cortical barrel does not develop. Due to the limited sensory capabilities of neonatal rats (no visual or auditory systems) the somatosensory system represents an ideal partner to the existing literature in the olfactory system in which the circuitry is not as well understood. Using 1-8 day old rat pups, the basic experimental method is to train neonatal rats in a classical conditioning procedure using the somatosensory system and later assessing the somatosensory cortex for neural changes associated with the training. The potential impact of this proposal is that it applies a new approach to an "established" research area. The learning paradigm is considered an enrichment paradigm and it has not been integrated into the neonatal whisker system plasticity research. The inclusion of an enrichment paradigm into this area of study will add a dimension to an existing cortical model of plasticity in which a deprivation paradigm is currently used. Although deprivation is very helpful in our understanding of systems, it becomes particularly useful when it is complimented with an enrichment paradigm. This proposal will enable the development of a strong foundation for a model in the whisker system which will capitalize on a growing interest in the characteristics of stimuli (emotional, significance) which appear to be important in promoting early experience-dependent behavioral and neural changes. Given the recent progress in my lab on defining the behavioral/functional development of the vibrissal system, and the recent explosion of interest in the role of emotional/behavioral significance of early experience on brain development, now is an ideal time to bring together these two lines of research. To do so, my proposal capitalizes on the wealth of knowledge concerning normal anatomical development of the rat vibrissal system. I
