Long-lasting and transgenerational effects of an environmental enrichment on memory formation

Abstract

It has long been believed that genetically-determined, but not environmentally-acquired, phenotypes can be inherited. However, a large number of recent studies have reported that phenotypes acquired from an animal’s environment can be transmitted to the next generation. Moreover, epidemiology studies have hinted that a similar phenomenon occurs in humans. This type of inheritance does not involve gene mutations that change DNA sequence. Instead, it is thought that epigenetic changes in chromatin, such as DNA methylation and histone modification, occur. In this review, we will focus on one exciting new example of this phenomenon, transfer across generations of enhanced synaptic plasticity and memory formation induced by exposure to an “enriched” environment.

Intergenerational Health Responses to Adverse and Enriched Environments

“…Environment plays a major role in the complex etiology of most of these diseases. This review identifies a possible mechanism that complicates our view of diseases such as cardiovascular diseases but also offers a target for future actions against them (2,50,51,57). A primary methyl donor in DNA methylation is delivered via a cycle that is catalyzed by many enzymes when folate, choline, betaine, B vitamins, and other micronutrients are present in food (1).…”

“…Environmental enrichments such as cultural participation have intragenerational healthpromotive effects that parallel the deleterious effects of adverse agents in society (10). Animal research reveals similar health-promotion effects by gametic epigenetic inheritance following environmental enrichment (2,42,43). The findings on germ line intergenerational responses to adverse and enriched environments in plant and animal research now have to be used to explore the phenomenon in humans.…”

Comparison of Area 17 Cellular Composition in Laboratory and Wild-Caught Rats Including Diurnal and Nocturnal Species

“…In the visual cortex, cats reared in enriched environments have a higher proportion of orientation-selective cells [Beaulieu and Cynader, 1991] and environmentally enriched mice a higher visual acuity [Prusky et al, 2000] than mice and cats reared in impoverished environments. Thus, in addition to genetic factors that contribute to the establishment, composition and plasticity of cortical areas, the sensory environment in which an animal is reared plays a large role on the resulting cortical organization and the behavior it generates [for cortical patterning review, see Krubitzer and Kahn, 2003; for enrichment reviews, see Arai and Feig, 2010;Baroncelli et al, 2010, andDiamond, 2001]. The current study takes a novel approach to addressing these issues by directly comparing the cellular composition in two groups of species that have been reared in dramatically different environments (natural versus laboratory), and in two closely related species that have undergone genetic modifications to the visual system associated with nocturnality and diurnality, that have been reared in a similar laboratory setting.…”

Épigénétique et réponses transgénérationnelles aux impacts de l’environnement

“…Ainsi, dans la cohorte d'Overkalix 1 , une malnutrition masculine chez le père, avant l'adolescence, se traduit par un risque plus faible de mortalité cardiovasculaire deux générations plus tard [5]. De plus, des environnements enrichis qui favorisent l'activité physique et cérébrale de l'animal, peuvent aussi induire des réponses transgénération-nelles favorables, qu'il s'agisse de performances meilleures, ou d'une réponse protectrice ou compensatrice dans le cas d'un conditionnement dans des situations défavorables [7]. Enfin, il ne faut pas non plus négliger [2].…”