RETRACTED: Odor maps in the olfactory cortex

Abstract

In the olfactory system, environmental chemicals are deconstructed into neural signals and then reconstructed to form odor perceptions. Much has been learned about odor coding in the olfactory epithelium and bulb, but little is known about how odors are subsequently encoded in the cortex to yield diverse perceptions. Here, we report that the representation of odors by fixed glomeruli in the olfactory bulb is transformed in the cortex into highly distributed and multiplexed odor maps. In the mouse olfactory cortex, individual odorants are represented by subsets of sparsely distributed neurons. Different odorants elicit distinct, but partially overlapping, patterns that are strikingly similar among individuals. With increases in odorant concentration, the representations expand spatially and include additional cortical neurons. Structurally related odorants have highly related representations, suggesting an underlying logic to the mapping of odor identities in the cortex

Synaptic Integration of Olfactory Information in Mouse Anterior Olfactory Nucleus

“…Axon terminal fields arising from mitral cells in different glomeruli partially overlap in their central targets (Zou et al, 2001). Immediate-early gene (IEG) studies show that odorants likely to activate separate populations of mitral cells activate distinct but partially overlapping regions of the olfactory cortex (Illig and Haberly, 2003;Zou et al, 2005). Moreover, IEG activation in some olfactory cortical neurons depends on odor combinations, suggesting a requirement for simultaneous input from separate mitral cell populations (Zou and Buck, 2006).…”

Functional units in the olfactory system

“…The largest projection is to the anterior and posterior piriform cortices, which have distinct cytoarchitecture and connectivity (1). Mitral cells receiving primary input from the same odorant receptors project in a patchy pattern across the piriform cortex (13), and the cells that are activated by different odorant receptors project to different areas in the anterior piriform cortex, such that different odorants elicit different activity patterns in that structure (14). The responses to different chemical features are thereby…”

“…thought to be brought back together in the piriform cortex for the perception of odor identity (14). Wilson and Stevenson (15) have pointed out that odor perception is likely to be more complex than the simple, faithful representation of external odorants in the brain.…”

Ric-8B, um provável GEF para Galpha-olf, promove expressão funcional de receptores olfatórios

“…Assim, deve existir uma maneira lógica e organizada de mapeamento do "código" também no córtex (Zou et al, 2005).…”

“…Assim, deve existir uma maneira lógica e organizada de mapeamento do "código" também no córtex (Zou et al, 2005). Camundongos knock-out para Gαolf (Belluscio et al,1998), adenilil ciclase III (Wong et al, 2000) e o canal CNG expresso nos neurônios olfatórios (Brunet et al, 1996) Interessante notar que para todos os componentes dessa cascata de sinalização foram descritos reguladores, exceto para a proteína Gαolf.…”