The Effect of Several Intertrial Intervals on the 1 Hz Interference Effect

Abstract

SUMMARYExperiments were conducted to evaluate the effect of two intertrial intervals of 1-Hz brain stimulation on kindling behavior induced by 60-Hz sine wave stimulation. In two experiments, the effective threshold intensity (ETI) to elicit a convulsion was determined on four separate occasions with 5 days of daily trials between determinations. On each day experimental rats were stimulated with 1-Hz current on the first and third trials for 120 seconds duration and with 60-Hz current for 30 seconds on the second trial (1-60-1 group). A second group was stimulated with 60-Hz current on each trial (60-60-60 group). A third group received no stimulation on Trials 1 and 3 and 60-Hz current on Trial 2 (X-60-X group). In Experiment I, the intertrial interval was 3 hours; a 24 hour interval was used in Experiment 2. The results were similar in both experiments. For the 1-60-1 group, there was a steady increase in the intensity required to elicit a convulsion with 60-Hz current from ETI to ETI. However, the 24 hour interval produced a lesser effect than did the 3 hour interval (or the 1 hour interval used in previous experiments). Rats in the other groups maintained relatively stable values from ETI to ETI, with a slight decline occurring. Suppression of convulsive behaviour on daily trials was present with the 1-60-1 groups, and nonexistent with the other groups.

The antiepileptogenic effect of electrical stimulation at different low frequencies is accompanied with change in adenosine receptors gene expression in rats

“…Kindling refers to the gradual electrographic and behavioral development in response to repeated application of brief intermitted and low‐intensity trains of electrical stimulation (Goddard et al., 1969). Although some investigators have focused on the efficiency of high‐frequency stimulation (Boon et al., 2007a,b; Van Roost et al., 2007), new experimental (Gaito & Gaito, 1981; Goodman et al., 2005; Mohammad‐Zadeh et al., 2007) and clinical (Yamamoto et al., 2002, 2006; Kinoshita et al., 2004) evidence shows that low‐frequency stimulation (LFS) has also inhibitory effect on seizure.…”

The effect of a 72-h intertrial interval on the 1-Hz suppression effect in rats

“…With 1• and 3-h intertrial intervals, the suppression effect was pronounced. The effect was present with a 24•h interval but was reduced greatly (Gaito & Gaito, 1981) ; these results indicate that the I-Hz suppression process is time dependent and suggest the possibility that it may dissipate completely at longer time intervals. The present experiment was conducted with a longer time interval, 72 h, to evaluate this possibility.…”

An evaluation of different methods of producing the 1-Hz suppression effect

“…With 1-and 3-h intertrial intervals, the suppression effect was pronounced. The effect was present with a 24-h interval but was reduced greatly (Gaito & Gaito, 1981). When the interval was increased to 72 h, the effect was minimal (Gaito, 1982).…”