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Updated: Aug 9, 2025
Preparation of Acute Brain Slices Using an Optimized N-Methyl-D-glucamine Protective Recovery Method
Published on: February 26, 2018
In the spotlight: How the brainstem modulates information flow
Markus Kofler1, Josep Valls-Solé2, Michael Thurner1
1Department of Neurology, Hochzirl Hospital, Zirl, Austria.
Objective:
The blink reflex (BR) to supraorbital nerve (SON) stimulation is reduced by either a low-intensity prepulse stimulus to digital nerves (prepulse inhibition, PPI) or a conditioning SON stimulus (SON-1) of the same intensity as the test (SON-2) stimulus (paired-pulse paradigm). We studied how PPI affects BR excitability recovery (BRER) to paired SON stimulation.
Methods:
Electrical prepulses were applied to the index finger 100 ms before SON-1, which was followed by SON-2 at interstimulus intervals (ISI) of 100, 300, or 500 ms.
Results:
BRs to SON-1 showed PPI proportional to prepulse intensity, but this did not affect BRER at any ISI. PPI was observed on the BR to SON-2 only when additional prepulses were applied 100 ms before SON-2, regardless of the size of BRs to SON-1.
Conclusions:
In BR paired-pulse paradigms, the size of the response to SON-2 is not determined by the size of the response to SON-1. PPI does not leave any trace of inhibitory activity after it is enacted.
Significance:
Our data demonstrate that BR response size to SON-2 depends on SON-1 stimulus intensity and not SON-1 response size, an observation that calls for further physiological studies and cautions against unanimous clinical applicability of BRER curves.
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