Word: neurone
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Neurotransmitters cross the synaptic gaps in the brain in milliseconds, stimulate the neuron on the other side and are then metabolized quickly...
...Already researchers are rushing to develop compounds that take aim at the tau and beta-amyloid proteins. They are also re-examining existing drugs that may offer therapeutic pportunities. Some experts, for example, speculate that antioxidants such as vitamin E and anti-inflammatories such as ibuprofen could help shield neurons from chemical damage. Others have seized on tantalizing hints that the female hormone estrogen may delay the onset of Alzheimer's disease in postmenopausal women. Estrogen appears to foster the brain's health by, among other things, spurring the growth of connections that link a single neuron to many others...
Scientists consider receptors--which are specially tailored protein molecules--and the substances that bind to them to be the critical junction in the ongoing chemical processes that underlie thinking, feeling, dreaming and remembering. For an electrical signal to travel from neuron to neuron in the brain, it must cross a minuscule gap, the synapse, between them. A number of different chemical messengers known as neurotransmitters ferry the signal across the synapse and then lock on to receptors that lie on the membrane of the next nerve cell in line...
Some neurotransmitters induce other neurons to fire; others dampen neuron activity. In either case, once the chemical locks on to the receptor, it sets in motion a cascade of chemical events in the receiving cell. This ongoing dance of neurotransmitters and receptors is the intricate code that brain cells use to communicate with one another...
Many psychoactive drugs--including opiates, the Valium-type compounds and angel dust--mimic the action of neurotransmitters by binding to particular receptors and influencing the neuron's firing. Pharmacologists have acquired the tools to screen new drugs quickly, testing their affinity for particular receptors by cloning, or duplicating, the receptors and then designing molecules that bind to them. So refined are the new techniques that scientists now know of 14 different receptors for serotonin, the ubiquitous chemical messenger that plays a critical role in sleep, mood, depression and anxiety. They have also discerned five different receptor subtypes for dopamine...