Heterogeneity of parvalbumin-containing neurons in the mouse main olfactory bulb, with special reference to short-axon cells and betaIV-spectrin positive dendritic segments.
The structural features of parvalbumin-positive neurons were studied in the mouse main olfactory bulb (MOB). Parvalbumin-positive neurons were heterogeneous, including numerous medium-sized interneurons in the external plexiform layer (EPL), some few large short-axon cells and a few periglomerular cells. Their overall distribution pattern and structural features resembled those of the rat MOB. However, large short-axon cells were frequently encountered in the internal plexiform and granule cell layers, which were rare in the rat MOB. In addition a few large short-axon cells were also encountered throughout the EPL. These short-axon cells extended their axons mainly in the EPL, usually making columnar axonal fields. Most parvalbumin-positive cells except periglomerular cells were confirmed to be glutamic acid decarboxylase positive. We examined the immuno-localization of the markers for the axon initial segments (AISs), betaIV-spectrin and sodium channels, to determine whether or not heterogeneous parvalbumin-positive neurons have axons. We confirmed their localization on the AISs of the large short-axon cells and periglomerular cells. However, these markers were encountered on some patch-like segments on the dendritic processes instead of the thin axon-like processes of the medium-sized EPL interneurons. The present study revealed the diversity of parvalbumin-positive neurons in the mouse MOB and their particular structural properties hitherto unknown.
Kosaka
Toshio
T
Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan. kosaka@med.kyushu-u.ac.jp
Kosaka
Katsuko
K
D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000648:ultrastructure; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology; D021961:Cell Membrane Structures / Q000378:metabolism / Q000648:ultrastructure; D048430:Cell Shape; D003712:Dendrites / Q000378:metabolism* / Q000648:ultrastructure; D005968:Glutamate Decarboxylase / Q000378:metabolism; D019044:Image Cytometry; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009830:Olfactory Bulb / Q000166:cytology / Q000378:metabolism*; D010320:Parvalbumins / Q000096:biosynthesis*; D015222:Sodium Channels / Q000096:biosynthesis; D013049:Spectrin / Q000096:biosynthesis*
D015415:Biomarkers; D010320:Parvalbumins; D015222:Sodium Channels; C504042:betaIV spectrin, mouse; D013049:Spectrin; D005968:Glutamate Decarboxylase