Digit tapping model of functional activation in the rat somatosensory cortex
Journal of Neuroscience Methods(2006)
Abstract
To establish a non-invasive model for functional activation of the rat somatosensory cortex, the forepaw digits of halothane-anesthetized rats were tapped while the blood flow (laser-Doppler flow, LDF) and somatosensory evoked potential (SSEP) responses in the forelimb area of the somatosensory cortex (S1FL) were measured. The distal phalanges of the forepaw digits were lightly tapped for 10s with an aluminum bar at frequencies between 1 and 40Hz, with 0.4cm total bar displacement. The LDF signal was normalized to the baseline preceding each stimulus block and averaged. The LDF response to digit tapping in the contralateral, but not ipsilateral S1FL, commenced within 1s, peaked at 11±0.5% (S.E.M.) above baseline within 2–3s, decreased to a plateau of 5±0.3% for the duration of the stimulation, and returned to baseline within 5–10s following tapping cessation. The LDF peak and plateau were not significantly different at different tapping frequencies. In the contralateral, but not ipsilateral, S1FLs, tapping produced an SSEP with positive (P1) and negative (N1) peaks at 27±0.5 and 47±0.2ms, respectively, after onset of the tap stimulation. As the tapping frequency increased from 1 to 20Hz, the P1–N1 peak-to-peak amplitude decreased. At 30 and 40Hz, the shortened interstimulus interval entrained the individual SSEPs into a steady-state evoked response. This study demonstrates that a robust functional activation of the forelimb region of primary somatosensory cortex of halothane-anesthetized rats can be produced by non-invasively tapping the forepaw digits and quantified with LDF and SSEP.
MoreTranslated text
Key words
Cerebral blood flow,Functional hyperemia,Evoked potential,Forepaw stimulation
AI Read Science
Must-Reading Tree
Example
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined