title: Effects of neocortical ectopias and environmental enrichment on Hebb-Williams maze learning in BXSB mice.
abstract: Approximately 40-60% of BXSB mice have neocortical ectopias, a developmental anomaly characterized by migration of neurons into the neuron-sparse layer I of cortex. Previous studies have shown that ectopic BXSB mice have superior reference, but inferior working, memory on spatial tasks. Female BXSB mice were housed either in an enriched environment or in standard cages at weaning. Subsequently, these animals were tested on four of the Hebb-Williams mazes in a water-based version of this maze. Theoretically, two of the maze configurations placed greater emphasis on reference memory to find the goal, whereas the other two favored working memory. Ectopics reared in standard housing conditions were better than nonectopics on mazes that favored the use of reference memory, but poorer on mazes that favored working memory. In contrast, subjects raised in the enriched environment showed no ectopia differences. A comparison of enriched and standard housing conditions found that the enriched animals had better reference memory but poorer working memory. The latter effect may be because the enriched environment, although more stimulating, did not change in time or space; and other researchers have shown that daily replacement of stimuli in complex environments is correlated with better working memory.
authors.affiliation: Biobehavioral Sciences Graduate Degree Program, University of Connecticut, Storrs 06269-4154, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Hoplight
authors.forename: G F
authors.initials: GF
authors.lastname: Sherman
authors.forename: L A
authors.initials: LA
authors.lastname: Hyde
authors.forename: V H
authors.initials: VH
authors.lastname: Denenberg
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001927:Brain Diseases / Q000473:pathology*; D002828:Choristoma / Q000473:pathology*; D004777:Environment; D005260:Female; D018782:Maze Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology*; D051379:Mice; D011897:Random Allocation; D013003:Somatosensory Cortex / Q000473:pathology*