T‐maze learning in weanling lambs

Abstract

A major advantage of sheep models in experimental studies of neurodevelopmental disorders (e.g., with prenatal neurotoxicant exposure) is that the equivalent of all three trimesters of human brain development occurs in sheep entirely in utero. However, studies of learning and memory in sheep are limited. The goal of this study was to extend the analysis of spatial learning and memory in adolescent sheep using several traditional T-maze tasks. Both 9- and 14-week-old lambs acquired a delayed non-matching to place task, but the older lambs learned the task significantly faster. In contrast, acquisition of a matching to place task was significantly more difficult. Lambs, like rodents, appear to have a predisposition toward learning “win-shift” spatial problems in a T-maze under appetitive motivation. Lambs also rapidly acquired a position habit and showed typical reversal learning curves. These findings support the use of T-maze tasks to assess behavioral outcomes in various sheep models.

Programming the brain: Common outcomes and gaps in knowledge from animal studies of IUGR

“…171 For example, if maternal undernutrition is imposed in rats only during gestation, this does not 172 impact the period of myelination, which occurs postnatally in rats, but commences prior to birth in 173 humans [ Figure 1,66]. This can be addressed by continuing maternal undernutrition postnatally 174 throughout lactation in the rat, but many studies do not do this. ( Tables 3 and 4) that persists into adulthood in small animal models ( in rats occurs at a neurodevelopmental stage similar to mid-gestation in the human [15].…”

Placental and fetal growth restriction, size at birth and neonatal growth alter cognitive function and behaviour in sheep in an age- and sex-specific manner

“…Sheep have a similar ontogeny of neurodevelopment to humans with neurogenesis, oligodendrocyte development and myelination commencing prenatally in both species [25,26]. Importantly, sheep demonstrate higher cognitive processing, including executive functions and problem solving [27,28], and learning, memory and cognitive flexibility can be tested in this species using maze tasks [28][29][30][31][32]. Impaired placentation, which reduces the supply of nutrients and oxygen reaching the fetus, is a major cause of IUGR in developed countries [33].…”