Ligand-gated ion channels mediate fast synaptic transmission in the central nervous s- tem (CNS) and at ganglionic and neuromuscular synapses. The nicotinic acetylcholine - ceptor (nAChR) is a member of the ligand-gated ion channel superfamily, which includes the 5-HT , glycine and GABA type A and C receptors. These receptors are known as Cys- 3 loop receptors, as all of them have a conserved sequence containing a pair of cysteines separated by 13 residues and linked by a disulfide bridge. nAChRs can be divided into two groups: muscle receptors, which are found at the skeletal neuromuscular junction where they mediate neuromuscular transmission, and neuronal receptors, which are found throughout the peripheral and central nervous system. Many of the early studies carried out on the subunit composition and structure of the nAChRs were performed on receptors isolated from the electric organ of Torpedo californica, as this tissue is very rich in nAChRs, and they were found to have a high degree of homology with the embryonic v- tebrate muscle type receptor. Muscle nAChRs are made up of five subunits arranged around a central pore (Fig. 1A, B). In Torpedo electric organ and vertebrate fetal muscle, the subunit composition is (a1) b1gd, and in adult muscle the g subunit is replaced by the e to give an (a1)b1ed 2 2 composition (Mishina et al. 1986).

Methamphetamine or Meth is by far one of the most dangerous drugs ever to hit the streets of America. With the ability to addict after one use, meth destroys whoever comes in contact with it. Present in every community, America has never seen a drug with the destruction power of meth. Meth will destroy lives, families, and the environment. Present in our schools and our workplaces, meth is one drug that will not go away. Learn the dangers associated with the labs, the users and the drug itself from multiple viewpoints. Meth is here now and is here to stay.