An attempt to measure effects of electric shock upon rat's drinking, eating and general activities over 24 hours a day

Effects of shocks, presented at a fixed time of day, on appetitive and general activity of rats

“…The brief removal of the subject from the box during the period of 1345-1400 h may have affected the pattern shown in the left panel of Figure 6. However, similar displacement was observed for eating in the previous single-rat experiment (Imada et al, 1983), in which the rat was never taken out of the apparatus at any time throughout the IO-day shock phase. (4) The results for the first 10 days of the shock phase were the same as those obtained for one rat in the previous experiment for which a more detailed frequency distribution of eating and drinking for 24 h was found (see Figure 3, Imada et al, 1983).…”

“…However, similar displacement was observed for eating in the previous single-rat experiment (Imada et al, 1983), in which the rat was never taken out of the apparatus at any time throughout the IO-day shock phase. (4) The results for the first 10 days of the shock phase were the same as those obtained for one rat in the previous experiment for which a more detailed frequency distribution of eating and drinking for 24 h was found (see Figure 3, Imada et al, 1983). (5) Although the aftereffects of shocks seem to have dissipated by the end of the 20-day shock phase, the anticipatory effect that appeared during the light phase was long lasting and was carried over into the to-day nonshock phase.…”

“…(2) Eating behavior was suppressed during both dark and light phases. To examine the effects of the 2100-h shocks on the patterns of consummatory behaviors over a wide range of time, midpoint-value analyses of the data were attempted, as in Imada et al (1983); the results are summarized in Figure 6. In this analysis, the clock time in which half of the total activity took place during a given period of time was calculated, as in the calculation of median values.…”

“…In foraging experiments, however, because of their nature, interactions of the effects of appetitive and aversive events are not of primary concern. To make all-day observation easier, Imada et al (1983) devised a box, named KGbox-24, in which rats' activities of eating, drinking, rearing, and locomotion could be measured over 24 h a day for many days, and in which electric shocks could be administered through the grid floor at any time of the day.…”

“…In the first pilot experiment with this apparatus (Imada et al, 1983), the effects of shocks, given at 2100 h (or I h after the start of the dark phase of the 12:12-h dark:light cycle), upon various activities of a rat were investigated for 10 days. The results of that experiment can be briefly summarized as follows: (1) A typical nightacti-~pattern was observed for all behavioral measures in both shock and nonshock phases.…”