it (Win-Shwe and Fujimaki, 2011). Here we report the effect of
CoO NPs on the brain. The mice fed with CoO NPs showed
the presence of these NPs in the brain indicating its retention
in it. Since the isolated brain pieces were divested of any traces
of blood, the entry of nanoparticles into the brain indicates its
entry into the neural tissue either through leaky passages of the
blood vessel’s endothelium reaching the brain or through compromising
the blood–brain barrier. Among all the regions of
the brain tested for the presence of CoO NPs, their retention
was maximum in the cerebral cortex, cerebellum, medulla
oblongata and olfactory bulbs as these four regions are most
likely to come in contact with the nanoparticles after they cross
the blood–brain barrier and enter the brain. Therefore, the
chances of the nanoparticles retention/deposition in these
regions are high