information:classification
Coding and perception

After binding the odorant, the receptor is activated and will send a signal to the glomeruli in the olfactory bulb. Each glomerulus receives signals from multiple receptors that detect similar odorant features. Because several receptor types are activated due to the different chemical features of the odorant, several glomeruli are activated as well. The signals from the glomeruli are transformed to a pattern of oscillations of neural activities of the mitral cells, the output neurons from the olfactory bulb. Olfactory bulb sends this pattern to the olfactory cortex. Olfactory cortex is thought to have associative memories, so that it resonates to this bulbar pattern when the odor object is recognized. The cortex sends centrifugal feedback to the bulb. This feedback could suppress bulbar responses to the recognized odor objects, causing olfactory adaptation to background odors, so that the newly arrived foreground odor objects could be singled out for better recognition. During odor search, feedback could also be used to enhance odor detection. The distributed code allows the brain to detect specific odors in mixtures of many background odors.