Centre-surround inhibition among olfactory bulb glomeruli

• Published in: Nature (London) Vol. 426; no. 6967; pp. 623 - 629
• Main Authors: AUNGST, J. L, HEYWARD, P. M, PUCHE, A. C, KARNUP, S. V, HAYAR, A, SZABO, G, SHIPLEY, M. T
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 11.12.2003; Nature Publishing Group
• Subjects: Animals; Axons - physiology; Biological and medical sciences; Contrast Sensitivity - physiology; Electrophysiology; Fundamental and applied biological sciences. Psychology; In Vitro Techniques; Mice; Mice, Transgenic; Neurology; Neurons; Odorants; Odors; Olfactory Bulb - cytology; Olfactory Bulb - physiology; Olfactory system and olfaction. Gustatory system and gustation; Rats; Sensory perception; Smell; Smell - physiology; Vertebrates: nervous system and sense organs; Vertebrata; Mammalia; Olfactory pathway; Mouse; Rodentia; Central nervous system; Electrophysiology; Olfactory bulb; Olfactory glomerulus; Encephalon
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature02185

Centre-surround inhibition--the suppression of activity of neighbouring cells by a central group of neurons--is a fundamental mechanism that increases contrast in patterned sensory processing. The initial stage of neural processing in olfaction occurs in olfactory bulb glomeruli, but evidence for functional interactions between glomeruli is fragmentary. Here we show that the so-called 'short axon' cells, contrary to their name, send interglomerular axons over long distances to form excitatory synapses with inhibitory periglomerular neurons up to 20-30 glomeruli away. Interglomerular excitation of these periglomerular cells potently inhibits mitral cells and forms an on-centre, off-surround circuit. This interglomerular centre-surround inhibitory network, along with the well-established mitral-granule-mitral inhibitory circuit, forms a serial, two-stage inhibitory circuit that could enhance spatiotemporal responses to odours.