9. THE MAUTHNER CELL
333
-
msec
Fig. 41. Fatigue of the LCI. In each record (a)-( c ) two successive stimuli were
delivered to the Mauthner axon and recordings made from the Mauthner cell body.
( a ) Single pair of stimuli; the reduction in amplitude of the second spike during the
depolarizing inhibitory potential (resulting from C1- leakage, see text) is a measure of
the conductance change during the collateral inhibition. ( b ) The pair of stimuli were
repeated once a second; a few superimposed traces are shown. ( c ) Repetition rate
of stimulus pairs was increased to two per second. Note the reduction in ( b ) and
the abolition in ( c ) of the inhibitory potential and the conductance change owing
to fatigue. The horizontal trace in each set shows the resting potential recorded
without stimulation of the Mauthner axon. From Furukawa and Furshpan (1963).
sudden surface splashing, usually fail unless many seconds are allowed
to elapse between successive stimuli. Indeed, it seems that this need for
a recovery period between stimuli (delivered to the freely swimming
animal) can be reasonably correlated with the fatigue in the neural