The effects of stress on memory and the hippocampus throughout the life cycle: Implications for childhood development and aging

Abstract

Studies in animals showing hippocampal atrophy and associated memory deficits in stress and aging have implications for stress and aging in humans. Clinical studies in traumatized human populations with posttraumatic stress disorder (PTSD) have replicated studies in animals, showing reduction in volume of the hippocampus measured with magnetic resonance imaging and associated memory deficits. Trauma at different stages of development (early childhood abuse versus trauma in later life due to combat) may influence the nature of memory deficits and hippocampal atrophy. Studies in aging human subjects are consistent with animal studies, although future research is needed in this area. The similarities between biological findings related to cortisol and the hippocampus in stress and aging in both animal and human studies raises the question of whether PTSD can be seen as a form of accelerated aging. Evidence that stress affects the hippocampus and the capacity for learning has broad implications for public health policy, underlying the need for additional resources in this important area and a reexamination of our understanding of factors influencing academic achievement.

Hormonal sensitivity of preterm versus full-term infants to the effects of maternal depression

“…More recently, such effects have been interpreted in terms of biological changes as mediators of this process. Researchers concerned with developmental psychopathology have given increasing attention to the neurohormonal responses of very young children to early trauma or stress (e.g., Bremner & Narayan, 1998;Gunnar, 2000; Nelson, 2000). However, interests have expanded beyond concern with trauma to a broader consideration of early experiences that predict children's later outcomes.…”

Music training improves verbal but not visual memory: Cross-sectional and longitudinal explorations in children.

“…Recently, researchers have begun to investigate the intrinsic connections between the changes of the neuroanatomical structures that relate to experience and the consequential development of associated cognitive functions (e.g., Bremner & Narayan, 1998;Chan, Ho, & Cheung, 1998;Kolb, 1996). Chan et al proposed that the impact of early life experience on the development of cognitive functions is predictable when an association with the effect of experience on neuroanatomy is established.…”

Étude de la dissociation, du stress physiologique et de la mémoire en fonction de la présence d'un état de stress post-traumatique chez des adolescents résidant en centre jeunesse /

“…Une diminution du volume de l'hippocampe entraîne des troubles mnémoniques chez des personnes en ESPT (Bremner & Narayan, 1998 (Bremner, 1999;Starkman, Gebarski, Berent, & Schteingart, 1992). Selon plusieurs recherches effectuées auprès des personnes en ESPT, le volume de l'hippocampe peut diminuer de 3,8% à 26% (Bremner, 1999;Bremner et al, 1995;Gurvits et al, 1996;Stein, Koverola, Hanna, Torchia, & McClarty, 1997 (Botez-Marquard, 1996).…”

“…Ce résultat pourrait également expliquer l'absence de relation significative entre ces deux variables. Si les taux de cortisol des participants en ESPT ne se distinguent pas de ceux des autres, cette hormone du stress n'a probablement pas pu endommager les hippocampes (Gurvits et al, 1996;Lupien et al, 1998) et conséquemment ni affecter la mémoire (Bremner & Narayan, 1998). Comme il n'y a pas de différence significative entre les groupes en ce qui concerne le stress physiologique et la mémoire, il est peu probable qu'il y ait une relation significative entre ces deux variables.…”