Progress in Brain Research
Hari Shanker Sharma, Aruna Sharma
We still lack our knowledge on the influence of nanoparticles on brain function in vivo during normal or hyperthermic conditions. Few reports indicate that when nanoparticles enter the central nervous system (CNS) they can induce neurotoxicity. On the other hand, drug delivery induced by nanoparticles in the brain improves neurorepair processes. Therefore, the inclusion of nanoparticles in body fluid compartments is likely to alter normal brain function and / or its response to additional stress, such as hyperthermia. New data from our laboratory show that metal-derived nanoparticles (eg Cu, Ag or Al, ≈50-60 nm) are able to induce brain dysfunction in normal animals and aggravate the brain pathology caused by hyperthermia of the whole body (WBH). Therefore, normal animals treated with nanoparticles (for 1 week) showed mild cognitive and cellular changes in the brain. The submission of these rats treated with nanoparticles to WBH led to profound cognitive and motor deficits, exacerbation of the breakdown of the blood-brain barrier (BBB), edema formation and brain pathology compared to naive animals. These new observations suggest that nanoparticles increase brain pathology and cognitive dysfunction in hyperthermia. The possible mechanisms of exacerbation induced by brain damage nanoparticles in WBH and its functional significance in relation to our current knowledge are discussed in this review.