Mary Elizabeth Blue, Ph.D.

Dr. Blue’s lab examines the roles neurotransmitters play as trophic agents in cortical development and plasticity. This research has demonstrated that monoaminergic and glutamatergic neurotransmitter systems are both altered by and influence injury in neonatal and adult hypoxia-ischemia animal models and in specific developmental disorders such as Down syndrome, autism and Rett syndrome (both in postmortem tissue and in animal models).

Activity-dependent plasticity plays an important role in the "sculpting" of synaptic connections in the postnatal human cerebral cortex and in the "reassignment" of cortex during recovery after early brain injuries. These plasticity studies focus on mechanisms by which cerebral cortex is influenced by peripheral stimuli and by which function is reassigned from one area of brain to another after neonatal injury. To study these mechanisms the rodent whisker-to-barrel system is used as a model of cortical plasticity. Rats and mice use their whiskers to navigate in their world and a precise "map" of the rodent face and whiskers is relayed through the brain to the cerebral cortex. Specialized anatomical configurations called "barrels" structurally and functionally linked to individual whiskers. Much like the reorganization of the human cortex after amputation, peripheral injury resulting from ablation of a single whisker follicle produces atrophy of the cortical barrel connected to it, and enhanced growth of surrounding barrels. These results suggest that glutamate receptors appear to mediate activity-dependent enlargement of some barrels and retraction of others in response to whisker clipping. Other studies have shown that neurotransmitter-specific afferents to the cortex (including acetylcholine-containing axons from the nucleus basalis) influence the degree of cortical plasticity.