An argument for an olfactory thalamus.
The mammalian olfactory system is unique in that sensory receptors synapse directly into the olfactory bulb of the forebrain without the thalamic relay that is common to all other sensory pathways. We argue that the olfactory bulb has an equivalent role to the thalamus, because the two regions have very similar structures and functions. Both the thalamus and the olfactory bulb are the final stage in sensory processing before reaching target cortical regions, at which there is a massive increase in neuron and synapse numbers. Thus, both structures act as a bottleneck that is a target for various modulatory inputs, and this arrangement enables efficient control of information flow before cortical processing occurs.
Kay
Leslie M
LM
Department of Psychology, Institute for Mind & Biology, The University of Chicago, Chicago, IL 60637, USA. lkay@uchicago.edu
Sherman
S Murray
SM
D000818:Animals; D006801:Humans; D008954:Models, Biological; D009433:Neural Inhibition; D009833:Olfactory Pathways / Q000502:physiology*; D012903:Smell / Q000502:physiology; D009435:Synaptic Transmission; D013788:Thalamus / Q000502:physiology*