Abstract
Acetylcholine or Strychinine of various concentration were adoministrated to spinal cord of Bufo vulgaris through arteria femaralis by plastic catheter. And then recording the reflex discharges of 9 th ventral root of spinal cord, their effects upon the spinal reflex (polysynaptic arc) were examined. Initial acceralation of reflex appeared at first by application of acetylcholine, and was followed by inhibition. In case of dilute acetylcholine injection, the initial acceralation became intense and the follwing inhibition weak.
But concentrated acetylcoline caused to acceralate at first slightly, and then to intensify the following inhibition, and often the reflex discharges disappeared 60 miniutes after application of acetylcholine.
Strychinine always acceralated the polysynaptic reflex. If strychinine of sufficient dosis was applied upon the completely inhibited spinal cord with preliminary treatment of acetylcholine, reflex discharges appeared again, and the spinal cord recovered from the inhibition.
And the acceralation of reflex caused by the application of the strychinine was brought to quiescence by following administration of acetylcholine.
From above mentioned facts, it is very probable that there exists antagonistic relation between strychinine and acetylcholine concerning to the spinal reflex.
