Liisa Tremere

Assistant Professor (Research), Brain & Cognitive Sciences

Contact Information
Education
Research Overview
Selected Publications
Research Support
Pinaud Lab Website

Contact Information

Meliora 107
Brain and Cognitive Sciences
University of Rochester
Rochester, NY 14627-0268
(585) 276-4023 (office)
(585) 442-9216 (fax)

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Education

PhD, Dalhousie University, Canada, 2000

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Research Overview

Our laboratory is interested in how heightened sensory drive competes for representation through cortical reorganization that displaces or overlays existing functional sensory cortex. In the somatosensory system, heightened use or "over-use" of a particular part of the skin will reassign neurons from neighboring representations of the body map to the region with increased touch rates. Our experiments are conducted in mice that have been subjected to a tactile over-stimulation behavioral task. We examine competition-based cortical reorganization from three perspectives:

First, we use electrophysiology to explore and characterize how the reassignment of cortical tissue alters firing patterns. We record from isolated units with multi-electrode arrays in anesthetized, awake restrained, or awake/behaving animals in order to define the extent of reorganization as a function of training time, as well as the functional specificity of re-wiring. We are particularly interested in understanding how the reorganization process respectively augments or impairs the responsiveness of neurons to new tactile input versus responsiveness to its former areas.

Second, we use pharmacological approaches to establish the degree to which reorganization plugs in new connectivity, rewires existing connectivity and/or abolishes older connections. To explore the full range of functioning pre- and post-reorganization circuitry we use microiontophoresis to locally administer pharmacological agents directed at a number of neurotransmitter systems. We are specifically interested in identifying how neuromodulators may re-weight sensory drive from different body regions in the acute state, once reorganization has been established, to reveal its new tactile responsiveness or the original developmentally-regulated identity assignment of that neuron.

Third, we use molecular biology along with electrophysiology in wild type and transgenic animals to identify biochemical and genetic mechanisms that drive and stabilize these changes. We are interested in understanding exactly which biochemical and genetic mechanisms cue the system to undergo experience-dependent changes. Earlier work by our group has shown a role for candidate plasticity genes in the cortical response to enriched sensory environments. We are interested in how the pathways that drive the expression of candidate-plasticity genes along, with their downstream targets, may initiate and/or stabilize the new firing properties of neurons in the reorganized somatosensory cortices.

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Selected Publications

BOOKS

Pinaud, R, Tremere, LA & De Weerd, P (Eds.) Plasticity in the Visual System: From Genes to Circuits. Springer-Verlag, New York (2005). ISBN: 0-387-28189-4.
Pinaud, R & Tremere, LA (Eds.) Immediate Early Genes in Sensory Processing, Cognitive Performance and Neurological Disorders. Springer-Verlag, New York (2006). ISBN: 0-387-33603-6.

SELECTED PEER-REVIEWED PUBLICATIONS

Tremere, LA & Pinaud, R (2006). Disparity for disinhibitory and excitatory effects during cortical reorganization. Int. J. Neurosci. 116: 547-564.
Tremere, LA & Pinaud, R (2005). Incongruent restoration of inhibitory transmission and general metabolic activity during reorganization of somatosensory cortex. Int. J. Neurosci. 115: 1025-1037.
Palmer, MJ, Taschenberger, H, Hull, C, Tremere, L & von Gersdorff, H (2003). Synaptic activation of presynaptic glutamate transporter currents in a ribbon-type but not in a conventional active zone nerve terminal. J. Neurosci. 23: 4831-4841.
Pinaud, R, Tremere, LA, Penner, MR, Hess, FF, Barnes, SA, Robertson, HA & Currie, RW (2002). Plasticity-driven gene expression in the rat retina. Mol. Brain Res. 98: 93-101.
Tremere, L, Hicks, TP & Rasmusson, DD (2001). Role of inhibition in cortical reorganization of the adult raccoon revealed by microiontophoretic blockade of GABA-A receptors. J. Neurophysiol. 86: 94-103.
Tremere, L, Hicks, TP & Rasmusson, DD (2001). Control of receptive field size by GABA-A receptors in reorganizing somatosensory cortex. Exp. Brain Res. 136: 447-455.
Pinaud, R, Tremere, L and Penner, MR (2000). Light-induced zif268 expression is dependent on noradrenergic input in rat visual cortex. Brain Res. 882: 251-255.

SELECTED BOOK CHAPTERS

Pinaud, R, Terleph, TA, Currie, RW & Tremere, LA (2006). Regulation of Immediate Early Genes in the Visual Cortex. In: Immediate Early Genes in Sensory Processing, Cognitive Performance and Neurological Disorders. R. Pinaud and L.A. Tremere (Eds.), Springer-Verlag, New York. Chapter 2, pp 13-33.
Pinaud, R, Filipkowski, R, Fortes, AF & Tremere, LA (2006). Immediate Early Gene Expression in the Primary Somatosensory Cortex: Focus on the Barrel Cortex. In: Immediate Early Genes in Sensory Processing, Cognitive Performance and Neurological Disorders. R. Pinaud and L.A. Tremere (Eds.), Springer-Verlag, New York. Chapter 5, pp 73-92.
Pinaud, R, Terleph, TA & Tremere, LA (2005). Neuromodulatory Transmitters in Sensory Processing and Plasticity in the Primary Visual Cortex. In: Plasticity in the Visual System: From Genes to Circuits. R. Pinaud, LA Tremere and P. De Weerd (Eds.), Springer-Verlag, New York. Chapter 7, pp 127-151.
Tremere, LA & Pinaud, R (2005). Intra-Cortical Inhibition in the Regulation of Receptive Field Properties and Neural Plasticity in the Primary Visual Cortex. In: Plasticity in the Visual System: From Genes to Circuits. R. Pinaud, LA Tremere and P. De Weerd (Eds.), Springer-Verlag, New York. Chapter 11, pp 229-243.
Tremere, LA, De Weerd, P & Pinaud, R (2005). A Unified Theoretical Framework for Plasticity in Visual Circuitry. In: Plasticity in the Visual System: From Genes to Circuits. R. Pinaud, LA Tremere and P. De Weerd (Eds.), Springer-Verlag, New York. Chapter 16, pp 347-355.
Tremere, LA, Pinaud, R & De Weerd, P (2003). Contributions of Inhibitory Mechanisms to Perceptual Completion and Cortical Reorganization. In: Filling-in: From Perceptual Completion to Cortical Reorganization. L. Pessoa and P. De Weerd (Eds.), Oxford University Press, San Francisco. Chapter 15, pp 295-322.

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Research Collaborators

Antonio Fortes, Research Associate, Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
Erich Jarvis, Associate Professor, Department of Neurobiology, Duke University Medical Center, Durham, NC, USA
Ernest Nordeen, Professor, Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA
Kathy Nordeen, Professor, Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA
Raphael Pinaud, Assistant Professor, Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA
Thomas Terleph, Assistant Professor, Department of Biology, Sacred Heart University, Fairfield, CT, USA

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