Ontogeny of spatial working memory in the subterranean rodentctenomys talarum

Abstract

While several works analyzed the spatial learning and memory capacities in adults of subterranean rodents, no study was done examining the development of these cognitive processes in pups of any of those species. Therefore, the development of spatial working memory in the South American subterranean rodent Ctenomys talarum was investigated by analyzing the pups' spatial performance in a delayed alternation task. When a short delay of 1 min was interposed between runs in the Y-maze, 20-day-old pups made more errors than 40- and 60-day-old pups. When longer intervals (10 min) were elapsed between runs, younger pups made approximately twice as many errors as the ones committed by 60-day-old pups, showing the age-dependent development of spatial working memory in this species of subterranean rodent. Increased space use by C. talarum pups, caused first by the appearance of independent exploratory behavior and later by the need of leaving maternal territory and construct a new burrow system, showed some correspondence with the improvements in the pups' spatial working memory performance, suggesting for the importance of this cognitive capacity in developing pups for which spatial learning and memory constitute essential abilities for survival and fitness.

Prepubertal castration causes the age‐dependent changes in hippocampal long‐term potentiation

“…A wealth of experimental evidence has connoted that different domains of cognitive functions, in particular spatial memory are influenced by age (Albert et al, ; Balota et al, ; Erickson and Barnes, ). Spatial learning and memory might develop from childhood and become adult‐like during adolescence (Brown et al, ; Schleich, ). The age‐related changes in spatial memory are happened along with gonad maturation and may be accompanied by modification of information storage mechanisms in some brain structures in particular hippocampus.…”

Thermoregulatory development and behavior of Ctenomys talarum pups during brief repeated postnatal isolation

“…after day 10, RMR starts to decrease. C. talarum offspring reach weaning at day 45 (Zenuto et al, 2002), achieving age of dispersal after day 60 (Schleich, 2010). During this period, pups reach adult T b (Zenuto et al, 2002;Antinuchi et al, 2007; Table 1), however RMR is still relatively high (0.92 mL O 2 /gh for adults; Luna and Antinuchi, 2007), probably due to an additional energy requirement related to their growth.…”

“…At this age, weaning period starts and pups show active exploratory behavior, displaying improvements in their spatial working memory performance. At dispersal age (~70 days old), individuals of C. talarum display further enhancements in their spatial abilities (Schleich, 2010).…”

“…Although several works studied physiological and behavioral ontogenetic characteristics of C. talarum pups with permanent access to the mother and siblings (Zenuto et al, 2002;Cutrera et al, 2003;Schleich and Busch, 2004;Schleich, 2010), no studies were conducted to assess the physiological and behavioral mechanisms that pups employ to face the effect of short maternal absence. In particular, the aim of this study was to evaluate if pups of C. talarum compensate for maternal and sibling absence bouts, and if it happens, which are the mechanism involved on the acquisition of physiological thermoregulation and development of spatial learning capabilities.…”

Prenatal predatory stress in a wild species of subterranean rodent: Do ecological stressors always have a negative effect on the offspring?

“…Pups become behaviorally and physiologically independent from their mother at about 60 days after birth (Cutrera, Antinuchi, & Busch, 2003;Zenuto et al, 2002). Therefore, the weaning period starts at this age, when pups start to display active exploratory behavior (Schleich, 2010). Sexual maturation age of this species is 6 months for females and 9 months for males (Malizia & Busch, 1991).…”