Chemical synapse cells, known as a gap junction. At gap junctions, cells approach within about 3.5 nm of each other, rather than the 20 to 40 nm distance that separates cells at chemical synapses. As opposed to chemical synapses, the postsynaptic potential in electrical synapses is not caused by the opening of ion channels by chemical transmitters, but rather by direct electrical coupling between both neurons. Electrical synapses are faster than chemical synapses. Electrical synapses are found throughout the nervous system, including in the retina, the reticular nucleus of the thalamus, the neocortex, and in the hippocampus. While chemical synapses are found
Nanoparticles for drug delivery to the brain stabilizing the nanoparticles and preventing the nanoparticles from aggregation. Metallic nanoparticles typically cross the BBB via transcytosis. Nanoparticle delivery through the BBB can be increased by introducing peptide conjugates to improve permeability to the central nervous system. For instance, recent studies have shown an improvement in gold nanoparticle delivery efficiency by conjugating a peptide that binds to the transferrin receptors expressed in brain endothelial cells. Also, solid lipid nanoparticles (SLNs) are lipid nanoparticles with a solid interior as shown in the diagram on the right. SLNs can be made by replacing the liquid lipid oil used in the emulsion process