* Three month inhalation exposure to low-level PM2.5 induced brain toxicity in an Alzheimer's disease mouse model.
- Although numerous epidemiological studies revealed an association between ambient fine particulate matter (PM2.5) exposure and Alzheimer's disease (AD), the PM2.5-induced neuron toxicity and associated mechanisms were not fully elucidated. The present study assessed brain toxicity in 6-month-old female triple-transgenic AD (3xTg-AD) mice following subchronic exposure to PM2.5 via an inhalation system. The treated mice were whole-bodily and continuously exposed to real-world PM2.5 for 3 months, while the control mice inhaled filtered air. Changes in cognitive and motor functions were evaluated using the Morris Water Maze and rotarod tests. Magnetic resonance imaging analysis was used to record gross brain volume alterations, and tissue staining with hematoxylin and eosin, Nissl, and immunohistochemistry methods were used to monitor pathological changes in microstructures after PM2.5 exposure. The levels of AD-related hallmarks and the oxidative stress biomarker malondialdehyde (MDA) were assessed using Western blot analysis and liquid chromatography-mass spectrometry, respectively. Our results showed that subchronic exposure to environmental levels of PM2.5 induced obvious neuronal loss in the cortex of exposed mice, but without significant impairment of cognitive and motor function. Increased levels of phosphorylated-tau and MDA were also observed in olfactory bulb or hippocampus after PM2.5 exposure, but no amyloid pathology was detected, as reported in previous studies. These results revealed that a relatively lower level of PM2.5 subchronic exposure from the environmental atmosphere still induced certain neurodegenerative changes in the brains of AD mice, especially in the olfactory bulb, entorhinal cortex and hippocampus, which is consistent with the nasal entry and spreading route for PM exposure. Systemic factors may also contribute to the neuronal toxicity. The effects of PM2.5 after a more prolonged exposure period are needed to establish a more comprehensive picture of the PM2.5-mediated development of AD.
Overview of noun change
The noun change has 10 senses (first 7 from tagged texts)
1. (46) change, alteration, modification -- (an event that occurs when something passes from one
state or phase to another; "the change was intended to increase sales"; "this storm is certainly a
change for the worse"; "the neighborhood had undergone few modifications since his last visit years
ago")
2. (45) change -- (a relational difference between states; especially between states before and
after some event; "he attributed the change to their marriage")
3. (17) change -- (the action of changing something; "the change of government had no impact on the
economy"; "his change on abortion cost him the election")
4. (13) change -- (the result of alteration or modification; "there were marked changes in the
lining of the lungs"; "there had been no change in the mountains")
5. (2) change -- (the balance of money received when the amount you tender is greater than the
amount due; "I paid with a twenty and pocketed the change")
6. (1) change -- (a thing that is different; "he inspected several changes before selecting one")
7. (1) change -- (a different or fresh set of clothes; "she brought a change in her overnight bag")
8. change -- (coins of small denomination regarded collectively; "he had a pocketful of change")
9. change -- (money received in return for its equivalent in a larger denomination or a different
currency; "he got change for a twenty and used it to pay the taxi driver")
10. variety, change -- (a difference that is usually pleasant; "he goes to France for variety"; "it
is a refreshing change to meet a woman mechanic")
Overview of verb change
The verb change has 10 senses (first 8 from tagged texts)
1. (57) change, alter, modify -- (cause to change; make different; cause a transformation; "The
advent of the automobile may have altered the growth pattern of the city"; "The discussion has
changed my thinking about the issue")
2. (54) change -- (undergo a change; become different in essence; losing one's or its original
nature; "She changed completely as she grew older"; "The weather changed last night")
3. (13) change, alter, vary -- (become different in some particular way, without permanently losing
one's or its former characteristics or essence; "her mood changes in accordance with the weather";
"The supermarket's selection of vegetables varies according to the season")
4. (7) switch, shift, change -- (lay aside, abandon, or leave for another; "switch to a different
brand of beer"; "She switched psychiatrists"; "The car changed lanes")
5. (6) change -- (change clothes; put on different clothes; "Change before you go to the opera")
6. (5) change, exchange, commute, convert -- (exchange or replace with another, usually of the same
kind or category; "Could you convert my dollars into pounds?"; "He changed his name"; "convert
centimeters into inches"; "convert holdings into shares")
7. (3) exchange, change, interchange -- (give to, and receive from, one another; "Would you change
places with me?"; "We have been exchanging letters for a year")
8. (3) transfer, change -- (change from one vehicle or transportation line to another; "She changed
in Chicago on her way to the East coast")
9. deepen, change -- (become deeper in tone; "His voice began to change when he was 12 years old";
"Her voice deepened when she whispered the password")
10. change -- (remove or replace the coverings of; "Father had to learn how to change the baby";
"After each guest we changed the bed linens")
--- WordNet end ---