Biological complexity: neuron receptors (Introduction)

by David Turell , Monday, May 02, 2016, 19:26 (3127 days ago) @ David Turell

Note the complexity of this neuron receptor just described:-http://phys.org/news/2016-05-views-nmda-receptor-action-aid.html-"NMDA receptors are embedded in the membrane of many nerve cells in the brain and are involved in the signaling between cells that is essential to basic brain functions, including learning and memory formation. Structurally, the NMDA receptor is made up of various protein segments, called domains, which together resemble a hot air balloon. The upper, balloon-like portion is comprised of the amino terminal domain (ATD); protruding from the outer surface of the cell is the ligand binding domain (LBD); and the lower, basket-like portion of the receptor, called the transmembrane domain (TMD), drops down inside the cell.-"Activation of the NMDA receptor requires binding of brain chemicals called neurotransmitters at specific sites on the LBD. This binding together with structural rearrangement of the ATD triggers the opening of the channel formed by the TMD. This molecular event causes charged atoms called ions flow into the cell. When this occurs in many channels at once, an electrical current is generated that rapidly propagates through the neuron and triggers the release of neurotransmitters. These chemical signals, in turn, bind to receptors on neighboring cells-***-"In addition to describing the NMDA receptor's balloon-like structure, Furukawa and the team of CSHL structural biologists have previously revealed many important features of NMDA receptors, including the distinctive ways in which a number of drug compounds attach to the receptor at its various binding sites. "The NMDA receptor architecture itself is quite complicated," says Furukawa, "but most recently we've been really fascinated by how each of its domains moves in a sophisticated but organized manner.'"-Comment: Be sure to look at the complex diagram. The brain is more than an electric machine. Various molecules are at work to modulated the connections and responses