Glomerulus development in the absence of a set of mitral-like neurons in the insect olfactory lobe

✍ Scribed by Oland, Lynne A. ;Tolbert, Leslie P.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 573 KB
• Volume: 36
• Category: Article
• ISSN: 0022-3034
• DOI: 10.1002/(sici)1097-4695(199807)36:1<41::aid-neu4>3.0.co;2-a

✦ Synopsis

Mitral cells are the first neurons in the mammalian olfactory bulb to synapse with olfactory receptor axons during glomerulus development, and in an invertebrate, the moth Manduca sexta, mitral-like neurons overlap very early with olfactory receptor axons as they begin to form protoglomeruli. The possibility for early interaction between receptor neurons and mitral-like neurons led us to ask whether such an interaction plays an essential role in glomerulus development. In the current study in the moth, we surgically removed a major class of these mitral-like neurons before glomeruli began to form and asked: (a) Is the formation of the array of olfactory glomeruli triggered by an interaction of the first-arriving receptor axons with the dendrites of mitral-like neurons? (b) At the level of individual glomeruli, must the mitral-like dendrites be in place either to maintain receptor axons in a glomerular arrangement, or to guide later-growing dendrites of other types into the developing glomeruli? Our results indicate that even without the participation of this group of mitral-like neurons, the array of sexually isomorphic ordinary glomeruli forms and the basic substructure of individual glomeruli develops apparently normally. We conclude that the mitral-like neurons in Manduca are not essential for the formation of ordinary olfactory glomeruli during development.