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Glomeruli: dynamic portals into the olfactory brain
Author(s) -
Ennis Matthew,
Shipley Michael T.,
Hayar Abdallah
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a84
Subject(s) - olfactory bulb , neuroscience , excitatory postsynaptic potential , inhibitory postsynaptic potential , olfactory system , sniffing , axon , chemistry , electrophysiology , patch clamp , biology , central nervous system
Main olfactory bulb glomeruli are the first site of synaptic integration in the olfactory system, yet the role of glomerular neurons in odor processing is poorly understood. In the present study, patch clamp recordings in rodent olfactory bulb slices were used to investigate the properties of glomerular neurons: external tufted (ET) periglomerular (PG) and short axon (SA) cells. ET cells exhibit rhythmic, intrinsically‐generated spike bursts at theta frequencies and receive monosynaptic olfactory nerve (ON) input. ET cell spike bursts entrain to ON stimuli delivered over the range of theta frequencies. ET cells of the same, but not different glomeruli, exhibit synchronous activity mediated by chemical and electrical synapses. By contrast, PG and SA cells have low levels of spontaneous spike activity driven by bursts of excitatory synaptic input, and most do not receive direct ON input. Paired recordings revealed that ET cells provide intraglomerular excitatory monosynaptic input to PG/SA cells. Thus, ET cells are excitatory and couple ON input to local inhibitory interneurons (PG cells) and to neurons that mediate interglomerular interactions (SA cells). ET cells may function to synchronize the activity of mitral/tufted cells with ON input, and to scale the strength of intraglomerular inhibition as a function of sniffing frequency. Supported by PHS grants DC03195, DC06356, DC05676, DC007123