Effects of Environment on Enhancing Functional Plasticity following Cerebral Ischemia

Abstract

Given the brain's capacity to recover from injury, plasticity may be enhanced following cerebral ischemia through environmental manipulation. Thus, the purpose of this study was to (1) determine the effects of early exposure to an enriched environment following ischemia on functional plasticity and (2) examine the relationship between morphological and behavioral plasticity. Adult female rats (n = 38) were divided into ischemia and control groups. Each group was further randomized to either standard (SC) or enriched conditions (EC). After 4 days of environmental exposure, rats were tested for 6 days in the water maze. Control and ischemia rats exposed to EC have increased total dendritic length (P < 0.05) as well as increased number of dendritic segments in the apical (P < 0.05) region of the hippocampal area compared to those housed in SC; furthermore, increased dendritic spine density in the apical (P < 0.05) region was also seen. Behavioral testing showed that ischemia rats exposed to SC have longer swim latencies (P < 0.05) and greater directional heading errors (P < 0.05) than ischemic rats exposed to EC; the latter group performed similar to controls. It is concluded that EC may be a potentially useful therapy in the recovery of spatial memory impairments seen after ischemia.

Modulation of Ischemia-Induced NMDAR1 Activation by Environmental Enrichment Decreases Oxidative Damage

“…The next day, both common carotid arteries were occluded for 12 min while the animals were awake. This period of carotid occlusion was used because it results in damage confined to the hippocampal area (Briones et al 2000(Briones et al , 2005. The criterion used to determine transient global cerebral ischemia was the bilateral loss of righting reflex within 2 min of occlusion.…”

“…However, one therapeutic strategy that has been overlooked in cerebral ischemia and oxidative stress studies is the use of enriched environment (EE) housing. Compelling evidence exists for the influence of EE housing on enhanced neuronal growth and restructuring and recovery following central nervous system (CNS) injury (Briones et al, 2000(Briones et al, , 2004(Briones et al, , 2006aSaucier et al, 2010;Will et al 2004;Xu et al, 2009;) yet little is known about whether EE housing has protective effects against oxidative damage. Interestingly, reports show that the neural plasticity seen after EE housing is mediated by glutamate through activation of NMDAR signaling (Andin et al, 2007;Li et al, 2007;(Wood et al, 2005).…”

Is exposure to enriched environment beneficial for functional post-lesional recovery in temporal lobe epilepsy?

“…Such positive influence of enrichment likely helps animals to cope with the cognitive demand during any given task in spite of having considerable hippocampal damage. Better memory performance in rats following stroke or ischemia with enriched housing also supports the above possibility (Johansson, 1996a, b;Johansson and Ohlsson, 1996;van Rijzingen et al, 1997;Briones et al, 2000).…”

Nurse-Enhanced Computerized Cognitive Training Increases Serum Brain-Derived Neurotropic Factor Levels and Improves Working Memory in Heart Failure

“…[18][19][20][21] Forty patients with reduced LVEF (< 40%) were randomized to eight M A N U S C R I P T…”