Faculty » Peter W. Hickmott

The organization of local circuitry throughout the brain plays a vital role in processing incoming information and controlling the behavioral responses to this information. This sort of organization has been closely studied in the cerebral cortex., particularly in primary sensory maps or representations. These maps are regions of the cortex that respond to specific sensory stimuli in a spatially organized across the map, in response to various manipulations that affect the activity of inputs to the cortex, and also to behavioral training and other natural stimuli. These sorts of cortical reorganizations are associated with important phenomena, such as recovery of function after stroke and improvements in performance due to sensory training. Furthermore, deficits in the control of cortical plasticity may be related to neuropathies from phantom pain and sensation after amputation to epilepsy to learning disabilities.

My research focuses on the basic cellular and synaptic properties that underlie the organization and plasticity of sensory maps, specifically the primary somatosensory cortex (S1). Ongoing experiments are examining the characteristics of local cortical circuitry with respect to the border between the representations of the forepaw and lower jaw in the normal map, and also in maps where the border regions is reorganized by a peripheral denervation or other change in the activity patterns to this region of cortex. In general, the local circuitry reflects the presence or absence of this border in the properties of excitation and inhibition onto neurons that lie close to the border, and also the morphology of these neurons. Techniques used in the laboratory include: in vivo and in vitro electrophysiology using extracellular and intracellular recording; analysis of neuronal morphology using standard and confocal microscopy; immunocytochemistry; and antero- and retrograde tracing of connections in the cortex.

Selected Publications

Marik, SA Hickmott, PW. Long Lasting Enhancement of Supragranular Horizontal Connections is Altered by Representational Borders in Adult Rat Somatosensory Cortex. J. Neurosci. Submitted.

Steen, PA, Mason, MT, Lefebfvre, Y, Pham, L & Hickmott, PW. Axonal bias at a representational border in adult rat somatosensory cortex (S1). J .Comp. Neurol. In Press.

Hickmott, PW. (2005) Changes in the intrinsic properties of pyramidal neurons during reorganization of adult rat somatosensory cortex. J Neurophysiol. 94: 501-511.

Hickmott, PW & Steen, PA. (2005) Large-scale changes in dendritic structure during reorganization of adult somatosensory cortex. Nature Neurosci. 8:140-142.

Henkemeyer, M, Itkis, O, Ngo, M, Hickmott, P & Ethell, I. (2003) The EphB1 and EphB2 receptor tyrosine kinases as a team shape dendritic spines in the hippocampus. J. Cell Biol. 163:1313-1326.

Burns, SA & Hickmott, PW. (2003) Effect of Representational Borders on Intrinsic Responses in Rat Somatosensory Cortex. Brain Res. 985:108-111.

Hickmott, PW & Merzenich, MM. (2002) Local circuit properties underlying plasticity of cortical maps. J Neurophysiol. 88:1288-1301.

Hickmott, P. W., & Merzenich, M. M. (1999). Dendritic bias of neurons in rat somatosensory cortex associated with a functional boundary. Journal of Comparative Neurology, 409, 385-399.

Hickmott, P. W., & Merzenich, M. M. (1998). Single-cell correlates of a representational boundary in rat somatosensory cortex. Journal of Neuroscience, 18, 4403-4416.

Buonomano, D. V., Hickmott, P. W., & Merzenich, M. M. (1997). Context sensitive synaptic plasticity and temporal-to-spatial transformations in hippocampal slices. Proceedings of the National Academy of Science (USA), 94, 10403-10408.

Hickmott, P. W., & Constantine-Paton, M. (1997). Experimental down-regulation of the NMDA channel associated with synaptic pruning. Journal of Neurophysiology, 78, 1096-1107.