Spatial Memory and Response Strategies in Rats: Age, Sex and Rearing Differences in Performance

Abstract

Rats reared in social isolation made more errors on a spatial memory task and made errors earlier in each trial than socially reared rats. The difference in performance only occurred when rats were isolated prior to 50 days of age, and it survived IOO days of subsequent social housing. IOO days of isolation after 50 days of age did not influence performance on the spatial memory task. Subsequent experiments suggest that spatial abilities may not differ between groups but that isolates are slower to learn to make a particular response and to locate a particular arm when spatial and response cues are irrelevant. In contrast to previous experiments, clear response strategies were seen in the present experiments. These were prevalent in the young (54-days-old) rats, were less common at 90 days and had completely disappeared by 180 days. Response strategies were more common in male rats and in socially reared rats.

Spatial and temporal response patterns on the eight-arm radial maze

“…High degrees of response stereotypy commonly occur when rats are tested on the radial maze: in particular, subjects choose sequences of adjacent arms [5,7,10,15,17,22,24,26]. Similar response patterning has been observed in Betta splendens [19], pigeons [2,18], mice [6,16], gerbils [25], and children [1].…”

Variations in radial maze performance under different levels of food and water deprivation

“…Subjects rapidly attain high choice accuracy, learning to collect all eight pieces of food in only eight or nine choices. Although response strategies, such as choosing adjacent arms in a clockwise order, are not necessary for accurate choice on the radial maze (Olton, Collison, & Werz, 1977;Roberts & Dale, 1981), response patterning is prevalent in radial maze research (Dale, 1982;Einon, 1980;Foreman, 1985). In the present experiment, we examined both choice accuracy and response patterns on the radial maze.…”

Hippocampal Function and Gonadal Steroids

“…Environmental conditions, such as complex or restricted (Brown, 1968;Smith, 1972),enriched or impoverished (Greenough et al, 1972), social or isolated conditions (Hymovitch,1952;Juraska et al, 1984;Seymoure et al, 1996), seem to affect spatial learning ability in a sexspecific manner. For example, male rats exhibited superior performance in learning maze tests compared with female rats if they were housed socially (Einon, 1980). But if they were housed in isolation, female rats exhibited a performance superior to that of male rats (Einon, 1980).…”