NMDA reÂ·cepÂ·tor. a type of glutamate receptor that participates in excitatory neurotransmission and also binds N-methyl-d -aspartate; may be particularly involved in the cell damage observed in individuals with Huntington disease.
â Ultramafic magma is extremely low in silica, with less than 45 percent of the same, but rich in heavier elements like iron and magnesium. It can have a temperature of about 2732 Â°F. It has very low viscosity and thus, its eruptive behavior is gentle.
Asteroids are made of rock and metal and broken away pieces of planets. They are grouped into three categories: Stony, Iron-Nickel, and a mixture of the two.Most asteroids that we know about fall into the first category, and are made of Silicates. A small percentage are Iron-Nickel.The rest form the third type. I believe that they are made of rocky bits left over from the formation of the inner planets. The run-of-the-mill asteroid is just one kilometer long.hey are grouped into three categories: Stony, Iron-Nickel, and a mixture of the two. Most asteroids that we know about fall into the first category, and are made of Silicates. A small percentage are Iron-Nickel.