Individual Listing

1109 BIOLOGICAL SCI
University of California
Riverside, CA 92521

Fiacco, Todd A

Assistant Professor

College of Natural and Agricultural Sciences

Cell Biology & Neuroscience


Biography

The overall research goal of the lab is to elucidate the function of astrocytes in synaptic signaling during normal physiological brain activity and also during brain pathology. Although astrocytes have been known for many years to possess numerous metabotropic receptors of the Gi, Gs, and Gq families that bind and respond to synaptically released neurotransmitter, the function of these receptors has remained unclear. Activation of astrocytic Gq GPCRs both in situ and in vivo can be visualized using indicator dyes that detect changes in intracellular Ca2+ concentration following release of Ca2+ from IP3 receptor sensitive internal stores. Visualization of astrocyte Ca2+ provides a nice readout of Gq GPCR signaling activity in the cell. Immediate research goals of the lab are to better understand fundamental properties of astrocyte Ca2+ signaling, that will provide insight into the volume of an astrocyte that is activated when astrocytic GPCRs are stimulated both “intrinsically” and following neuronal synaptic activity. Novel transgenic tools combined with modern Ca2+ imaging and electrophysiological techniques are used to measure astrocyte Ca2+ and record astrocyte currents as well as neuronal synaptic activity in the hippocampus.

Publications

Petravicz J, Fiacco TA, McCarthy KD. Loss of IP3 receptor-dependent Ca2+ increases in hippocampal astrocytes does not affect baseline CA1 pyramidal neuron synaptic activity. Journal of Neuroscience 28(19):4967-73, 2008.

Djukic B, Fiacco TA, McCarthy KD. Astrocyte signaling systems in physiology and pathology. In: Immune and Glial Regulation of Pain, edited by Joyce A. DeLeo, Linda S. Sorkin, and Linda R. Watkins, IASP Press, Seattle, pp.229-247, 2007.

Fiacco TA, Agulhon C, Taves S, Petravicz J, Casper K, Dong Xinzhong, Chen J, McCarthy KD. Selective stimulation of astrocyte calcium in situ does not affect neuronal excitatory synaptic activity. Neuron 54:611-626, 2007.

Fiacco TA, McCarthy KD. Astrocyte calcium elevations: Properties, propagation, and effects on brain signaling. Glia 54(7):676-690, 2006.

Fiacco TA, McCarthy KD. Intracellular astrocyte calcium waves in situ increase the frequency of spontaneous AMPA receptor currents in CA1 pyramidal neurons. Journal of Neuroscience 24:722-732, 2004.

Fiacco TA, Rosene DL, Galler JR, Blatt GJ. Increased density of hippocampal kainate receptors but normal density of NMDA and AMPA receptors in a rat model of prenatal protein malnutrition. Journal of Comparative Neurology 456:350-360, 2003.

Tonkiss J, Shultz P, Shumsky JS, Fiacco TA, Vincitore M, Rosene DL, and JR Galler. Chlordiazepoxide-induced spatial learning deficits: dose-dependent differences following prenatal malnutrition. Pharmacology, Biochemistry, and Behavior 65(1):105, 1999.