Associate Professor, Biological Sciences Carnegie Mellon University Phone: (412) 268-1198 Email: barth@cmu.edu

Ph.D., University of California

Research Interests

A defining characteristic of the neocortex is its ability to exhibit experience-dependent plasticity. Indeed, the phenomenal expansion of this brain area in mammals and especially primates is likely related to the neocortex's ability to encode information. The mechanisms by which this is accomplished, however, remain obscure. Although experience-dependent plasticity can be induced in both young and adult animals, it appears that the processes of developmental and adult plasticity may be quite dissimilar.

We are interested in identifying the molecules and pathways involved in developmental and adult plasticity using both in vivo manipulations to induce changes in synaptic strength, as well as whole-cell electrophysiological recordings. One ongoing project examines the changes in long-term potentiation and long-term depression that occur at a particular synapse, the thalamocortical synapse, that occur during development. Using a variety of genetic and pharmacological manipulations, we are narrowing into some crucial differences between neonatal and adult plasticity at this site.

Another project attempts to combine systems-level, behavioral plasticity with an understanding of the neocortical circuits involved in these events. For example, after an animal experiences certain types of sensory stimulation, neocortical neuronal responses are enhanced and gene transcription is activated in a small group of cells. We would like to be able to precisely identify the cells that are responsible for this enhancement. This subset of neurons may have some defining characteristics in terms of gene expression, electrophysiological properties, and anatomical projections. We are making some transgenic mice that will allow us to image, in a slice preparation, these activated cells, and more fully characterize their properties.

Recent Publications

• Clem RL, Barth AL:  Ongoing in vivo experience triggers synaptic metaplasticity in the neocortex.  Science 319: 101-104, 2008.
• Barth AL:  Visualizing circuits and systems using transgenic reporters of neural activity.  Curr Opin Neurobiol 17(5): 567-71, 2007.
• Glazewski S, Benedetti BL, Barth AL:  Ipsilateral sensory deprivation enhances cortical plasticity.  J Neurosci 27(14): 3910-20, 2007.
• Pfenning AR, Schwartz R, Barth AL:  A comparative genomics approach to identifying the plasticity transcriptome.  BMC Neurosci 8: 20, 2007.
• Clem RL, Barth AL: Pathway-specific trafficking of native AMPARs by in vivo experience.  Neuron 49(5): 663-70, 2006.
• Barth AL, Gerkin RC, Dean KL:  Alteration of neuronal firing properties in a fosGFP transgenic mouse.  J Neurosci 24: 6466-6475, 2004.