ORIGIN OF AUDITORY FRACTAL RANDOM SIGNALS IN GUINEA-PIGS

IN guinea pigs, the constant iontophoretic release of transmitter agon ists in the synaptic cleft of inner hair cells (IHC) triggers chemical ly an irregular and bursting mode of spiking discharge, subsynapticall y recorded in the afferent dendrites. The tendency to form spike clust ers appears to be independent of the quality and quantity of the used test substances, the excitatory amino acids N-methyl-D-aspartate (NMDA ) and pha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA). The recorded spike trains show a remarkable stability of the calculate d individual box-counting dimension characterizing the bursting behavi our as a fractal random point process. The fractal kinetics seems to r eflect molecular instabilities of cochlear afferent glutamate receptor s, determining the mode of the signal transmission in the auditory per iphery.