@oristarA,
oristarA wrote:
Context:
The ageing systemic milieu negatively regulates neurogenesis and cognitive function
In the central nervous system, ageing results in a precipitous decline in adult neural stem/progenitor cells and neurogenesis, with concomitant impairments in cognitive functions1. Interestingly, such impairments can be ameliorated through systemic perturbations such as exercise1. Here, using heterochronic parabiosis we show that blood-borne factors present in the systemic milieu can inhibit or promote adult neurogenesis in an age-dependent fashion in mice. Accordingly, exposing a young mouse to an old systemic environment or to plasma from old mice decreased synaptic plasticity, and impaired contextual fear conditioning and spatial learning and memory. We identify chemokines—including CCL11 (also known as eotaxin)—the plasma levels of which correlate with reduced neurogenesis in heterochronic parabionts and aged mice, and the levels of which are increased in the plasma and cerebrospinal fluid of healthy ageing humans. Lastly, increasing peripheral CCL11 chemokine levels in vivo in young mice decreased adult neurogenesis and impaired learning and memory. Together our data indicate that the decline in neurogenesis and cognitive impairments observed during ageing can be in part attributed to changes in blood-borne factors.
I would certainly skip the negative before regulates... It either negatively affects, or effects; the words being nearly synoymous, or simply regulates, which has neither a negative or positive connotation... Excuse my spelling... Just killing a few moment that might be more profitably spent elsewhere...
Milieu is a seldom used and less understood word, and the word you might be looking for is environment, or simply, aging system... There is a word I can't think of at the moment which actually means what you are saying, of a degradation of ability associated with time, but in this instance I will not blame my age, but fatigue or distraction...
I would keep looking for the right word, but do not give up on writing clear and simply statements of fact... You cannot reduce all the moves in a chess game to a single sentence except by reporting who won, and they may be true enough, but the time taken to express the situation generally and concisely is well spent... We cannot communicate the experience of life nearly as quickly as we can live them, and the fact that you may well take as granted is that communication is a slow and imperfect process that is only acceptable in the sense that it is ongoing and errors or misunderstandings can be corrected... The truly great communicators in history were simplifiers, and by this I do not mean that they always spoke the truth... I mean: they were able to phrase their ideas in such a simple and clear fashion that the common people who are most prone to action without forethought could understand them without doubt... Few of us have a dictionary between our ears... From my square head it is obvious that I do... Write for those unlike me, and you are certain to be a success...
Stumble It!
Tweet This
Bookmark on Delicious
Share on Facebook
Share on MySpace