THE CHARACTERISTIC OF AFFERENT ACTIVITY OF AMPULLARY ELECTRORECEPTORS IN CATFISH PARASILURUS ASOTUS

The spontaneous and evoked activity of electroreceptors were electrophysiologically studied. The results are:1. The spontaneous discharge rate ranged from 15 to 85 imp/s with a modus of 50 imp/s for 126 organs of 18 animals.2. By analysis of periodic histograms and interspike interval histograms of responses to sinusoidal electrical stimulations, the frequency response characteristic was determined. The frequency response curve shows a band pass type, the band width ranged from 5Hz to 30Hz and the best frequency is around 15Hz.3. The thresholds of responses for 47 organs were measured by injection of sinusoidal current into the ampulla. The threshold values were less than 0.1nA ( 61V/cm) for 35 organs (74% ), and less than 0.01nA( 6.1V/cm)for 9 organs (19% ).