Functional magnetic resonance imaging of the primary somatosensory cortex in piglets

Dartmouth–Hitchcock Medical Center, LEB, New Hampshire, United States
Journal of Neurosurgery (Impact Factor: 3.74). 05/2006; 104(4 Suppl):259-64. DOI: 10.3171/ped.2006.104.4.259
Source: PubMed


The piglet is an excellent model for the developing human brain, and has been used increasingly in various centers for studies of traumatic brain injury and other insults. Unlike rodent or primate models, however, there are few behavioral scales for the piglet, and the available ones are used to test general responsiveness rather than specific functional outcome. The differing behavioral repertoires of animals of different ages provide an additional challenge when age-dependent injury responses are compared. To overcome these experimental limitations of piglets in brain injury research, the authors developed a functional magnetic resonance (fMR) imaging paradigm that can be used to track recovery in the somatosensory cortex over time in anesthetized animals of different ages.
Fifteen fMR imaging studies in eight piglets were performed before and after scaled cortical impact injury to the primary somatosensory cortex subserving snout sensation. Specific anesthetic and imaging protocols enabled visualization of cortical activation, and comparison with somatosensory evoked potentials obtained before and after injury was obtained. A piglet brain template for group-level analysis of these data was constructed, similar to the fMR imaging techniques used in humans, to allow for group comparisons and longitudinal change analysis over time.
Loss of function in a specifically traumatized cortical region and its subsequent recovery over time can now be demonstrated visually by fMR imaging in the piglet. Besides its value in understanding intrinsic recovery mechanisms and plasticity at different ages, this functional outcome measure will enable the use of the piglet model in treatment trials specifically designed for the immature brain.

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    • "Studies have shown the activity of this area through functional magnetic resonance imaging (fMRI) (Grate et al., 2003; Duhaime et al., 2006). In addition to fMRI, sensory responses of the snout in the somatasensory cortex can be analyzed with electroencephalograph (EEG) and focal injury to the area abolishes EEG and fMRI activity when the snout is touched (Duhaime et al., 2006). These established models can be helpful for the discovery of effective treatments for head injury and the extent of cellular genesis after injury. "
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