Ling Wang, Ph.D.
Assistant Project Scientist

Current Research

The aims of my research are to elucidate both the structural plasticity of individual "learning" neurons in the context of behavioral experience and the role of brain derived neurotrophic factor (BDNF) in modulating brain "structural plasticity".

Structural plasticity in the context of experience has been explored in previous studies, primarily by two methods: electron microscopy and Golgi staining. Morphological changes have been identified in motor neurons of the adult brain in the context of novel experience and training. However, it remains unknown whether these changes are unique and restricted to individual neurons that are utilized in a specific function, or occur in a generalized manner within broad functional units of the cortex. Past studies have sampled general populations of cortical neurons within cortical functional units, but have not examined structure at the level of individual neurons specifically participating in a given neural function.

This distinction has important implications for understanding the nature of higher order cortical processing. Is the locus of experience structurally represented within individual neurons, or do structural changes occur only in broader regions of cortical networks supporting ongoing activity? Can a single neuron within a functional unit of cortex undergo structural modification in the context of use, while an adjacent, non-activated neuron does not?

Hebbian theory, which states that active synapses are reinforced at the expense of inactive synapses, suggests that structural changes would be restricted to neurons undergoing experienced activation and motor map reorganization. To address whether or not this is the case, we are using retrograde tracing in combination with intracellular cell filling to study structural modifications of individual corticospinal neurons in rats undergoing skilled forelimb motor training.

Representative Lucifer Yellow (green) filled corticospinal neuron. Click to view complete figure in a new window.

BDNF, a member of neurotrophin family, is the most abundant neurotrophic factor in the brain. Deficiencies of BDNF have been shown to correlate with impairments in learning and memory. Learning and memory is believed to involve both short-term changes in electrical properties and long-term structural alterations in synapses. BDNF is involved in the regulation of synaptic strength, influences the development of patterned connections and promotes the growth and complexity of dendrites in the cerebral cortex. Using the aforementioned approaches in conjunction with other molecular and biochemical techniques, we are investigating whether BDNF is involved in training-induced plastic structural changes as well as neuronal structural changes induced by the processes of aging.


Recent Publications

Wang L, Conner J, Nagahara A and Tuszynski M. Structural plasticity of identified corticospinal neurons associated with skilled forelimb training in rats. Society for Neuroscience Abstract (2006): vol32, 161.12

Wang L, Andersson S, Warner M, and Gustafsson J. ER knockout mice reveal a role for ER in migration of cortical neurons in the developing brain. Proceedings of the National Academy of Sciences of the United States of America (2003): 100(2):703-708.

Wang L, Schuster GU, Hultenby K, Zhang Q, Andersson S, Gustafsson J. Liver X receptors in the central nervous system: from lipid homeostasis to neuronal degeneration. Proceedings of the National Academy of Sciences of the United States of America (2002): 99(21):13878-13883

Wang L, Andersson S, Warner M, Gustafsson J. Morphological abnormalities in the brains of estrogen receptor knockout mice. Proceedings of the National Academy of Sciences of the United States of America (2001): 98(5):2792-2796.