Computation of frequency-to-spatial transform by olfactory bulb glomeruli.
A physiological simulation of 2.5% of the input and inhibitory neurons and 25% of the primary mitral/tufted cells in a single mammalian olfactory bulb glomerulus was constructed. This physiological simulation used the integrate-and-fire paradigm with realistic activation curves and synaptic delays. The dendritic integration incorporated non-linear interactive effects of individual cell excitatory and inhibitory post-synaptic potentials (PSPs) from both axodendritic and dendro-dendritic synaptic contacts. Refractory periods for granule-cell inhibition of mitral/tufted cell activity lead to relatively fixed-frequency rhythmic activity in the glomerulus, independent of the input frequency from the olfactory nerve. Though the frequency of mitral/tufted cell firing in bulb was approximately independent of input frequency, the number of cells active in the glomerulus was a roughly-linear function of input frequency to the glomerulus, indicating the mechanism's ability to function as a frequency-to-spatial encoder.
Antón
P S
PS
Center for the Neurobiology of Learning and Memory, University of California, Irvine 92717.
Lynch
G
G
Granger
R
R
D000818:Animals; D005071:Evoked Potentials; D008322:Mammals; D008433:Mathematics; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D009812:Odorants; D009830:Olfactory Bulb / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D009832:Olfactory Nerve / Q000502:physiology; D013569:Synapses / Q000502:physiology