At present the reasons why proinflammatory environment impairs proliferation and survival more potently but leaves neuronal maturation more or less intact are not clear.
As we had previously shown that an impoverished environment impaired wound healing, we focused on wound healing as our measure of physical health.
This is because a prior study, which employed non-transplant experimental models, found that the aged host environment impaired the turnover of memory CD44hi CD8+ T cells via heightened BCL-2 expression and higher type I interferon levels [24].
Lunn and Campbell, et al. [ 2] proposed that frequent gastrointestinal infections, arising from unhygienic and unsanitary environments, impair small intestinal mucosal function, and explained up to 64% of the observed height and weight faltering of Gambian infants.
The cyclic wet-dry environments impaired the corrosion resistance of materials and caused more corrosion damage compared to acid condensation.
In both ammonium-toxic and potassium-limited environments, impaired cellular growth was observed, which can be attributed to high energetic costs of increased ammonium assimilation to synthesize and excrete amino acids.
Mice lacking the NMDAR 2A subunit gene GluRε1 (the mouse homolog of the GRIN2A gene in humans) show increased spontaneous locomotor activity in novel environments, impaired latent learning associated with selective attention [ 17] and deficits in spatial learning [ 18].
So, living in an adverse environment could impair the development of primaries levels and it would impact in the development of superior levels (Stuss 1992).
Future studies are warranted to determine the factors within the aged host environment that impair the expansion of antigen-specific, naïve CD8+ T cells.
