Facilitation of electric forepaw stimulation-induced somatosensory activation in rats by additional acoustic stimulation: An fMRI investigation

The influence of scanner acoustic noise on somatosensory activation pattern in rat cortex was investigated by functional magnetic resonance imaging (f MRI) using the blood oxygenation level-dependent (BOLD) contrast. This was achieved by two approaches. The first approach was to compare a conventiona l, loud fMRI sequence with a new sequence, in which the noise level was red uced by about 30 dB. In the second approach, the inner ear of the animal wa s destroyed, resulting in deafness. We compared the activation patterns obt ained with both sequences before and after cochleotomy. The activated area was larger when data were sampled with background noise, and was also large r before cochleotomy than after. Thus, facilitation of somatosensory activa tion is induced by additional acoustic stimulation. Magn Reson Med 44:317-3 21, 2000. (C) 2000 Wiley-Liss, Inc.