GABA Gating system
<p class="default">03:35 PM, November 03, 2006 
 
Benzo's are among many sleep-promoting substances that work on a molecular structure in the brain known as the GABA receptor-chloride channel complex, or simply the GABA gating system. 
When the central nervous system chemical GABA (see page 11) lands at a specific "docking site" on one of these structures, it allows the chloride channel in the middle to open temporarily and let chloride flow through it. This chloride flow keeps the cell from becoming activated and, when it happens to a lot of cells, the nervous system is quieted by this action. 
Benzodiazepines can't do anything by themselves - that is, without GABA - which is why they're considered relatively safe. They seem to make it more likely that a GABA molecule will open the chloride channel, but they can't open the chloride channel alone. Therefore, their action is limited by how much natural GABA is around. 
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