Olfaction in the environment

Olfaction is the sense of smell.  As humans we rarely get to smell chemicals in isolation.  We are always confronted by hundreds of molecules some that combine to make familiar smells.  How olfactory information is coded in the brain to allow for proper perception is still being researched and the process is not completely understood. However, what is known is that the chemical nature of the odorant is particularly important as there may be a chemotopic map in the brain; this map would show specific activation patterns for specific odorants. When an odorant is detected by receptors, the receptors in a sense break the odorant down and then the brain puts the odorant back together for identification and perception.  The odorant binds to receptors which only recognize a specific functional group, or feature, of the odorant, which is why the chemical nature of the odorant is important.

http://www.youtube.com/watch?v=F2FJKBKPpNQ