Effects of enriched environment in spatial learning and memory of immature rats submitted to early undernourish and seizures

Abstract

We recently reported that early undernourishment and seizures to the rat brain resulted in morphological changes and progressive learning and memory disability, which started at around 6 week later and is representative of human adolescence. The purpose of the present study was to examine whether enriched environmental can recovery this slowly progressing deficits in early undernourished and in two different models for seizures. Undernourished groups were maintained on a nutritional deprivation regimen from post-natal day 2 (P2) to P15. From P8 to P10, recurrent seizures (RS) groups were exposed to three seizures per day, while status epilepticus (SE) groups experienced status epilepticus at P16, both induced by flurothyl. Next, animals were exposed to enriched environment between P30 and P60. Beginning at P61, all groups were trained and tested in the Morris water maze (MWM). Enriched environment led to a significant benefit in learning and retention of visual-spatial memory, being able to reverse the cognitive impairment generated by undernourishment and SE.

Enhanced susceptibility to seizures modulated by high interleukin‐1β levels during early life malnutrition

“…Since stress could be a source that may exacerbate or trigger seizures (Novakova et al, 2013;Van Campen et al, 2014), our study may indicate that the production of corticosteroids during early malnutrition may contributes to the vulnerability of the brain to seizure. The increased corticosterone levels in hippocampus at P7 malnourished rats may explain the long-term retention impairments in memory and learning seen in the adulthood as we previously reported (Hemb et al, 2010;Simão et al, 2012). The data presented in this study showed no differences on corticosterone levels in serum between malnourished and nourished pups, and it thus seems possible that maternal care and time after food deprivation masked important variations in the consequences of malnutrition.…”

Enriched Environment Altered Aberrant Hippocampal Neurogenesis and Improved Long-Term Consequences After Temporal Lobe Epilepsy in Adult Rats

“…Considerable evidences had shown that EE treatment was beneficial for cognitive functions both in normal and pathological conditions (Cao et al 2008;Anastasia et al 2009;Hirata et al 2011;Simao et al 2012;Beauquis et al 2013;Doulames et al 2014;Piazza et al 2014). However, few studies addressed whether and how EE Xiaoqian Zhang and Tingting Liu contributed equally to this work.…”

Effects of undernourishment, recurrent seizures and enriched environment during early life in hippocampal morphology

“…Experimental studies suggested that enriched environment stimulates neuronal plasticity, facilitate learning and reduces cognitive impairment in animals with preliminary brain injury (Van Praag et al, 2000). We previously demonstrated that enriched environment was an effective treatment in the recovery of spatial memory in rats exposed to early undernourishment and seizures, being able to reverse the cognitive deficits generated by these disorders (Simão et al, 2012). Considering that environmental stimulation probably results in structural changes in neural cells to promote better cognitive outcome, it is reasonable to suggest that it could influence the hippocampal morphology.…”

“…The association of undernourishment and seizures, that is a common clinical situation, might augment the deleterious effects of seizures in the developing brain (Simão et al, 2012). Little attention has been given to the influence of environmental enrichment in immature rats with recurrent seizures and undernourishment in brain structures.…”