14755530 |
McMillan Carr V, Ring G, Youngentob SL, Schwob JE, Farbman AI: Altered epithelial density and expansion of bulbar projections of a discrete HSP70 immunoreactive subpopulation of rat olfactory receptor neurons in reconstituting olfactory epithelium following exposure to methyl bromide. J Comp Neurol. 2004 Feb 16;469(4):475-93. A previously described subpopulation of rat olfactory receptor neurons, the 2A4 (+) ORNs, is 1) distinguished by intense constitutive cytoplasmic immunoreactivity to antibodies to the 70-kD heat shock protein (HSP70); 2) occurs sparsely but consistently through ventral and lateral olfactory epithelium (OE); and 3) projects to just two to three consistently located glomeruli in each olfactory bulb (OB) (Carr et al. [1994] J Comp Neurol 348:150-160). Immunoreactivity appears not to be stress-related. To examine the persistence of these features following destruction and reconstitution of the OE, rats were subjected to methyl bromide-induced OE lesion (Schwob et al. [1995] J Comp Neurol 59:15-37; Schwob et al. [1999] J Comp Neurol 412:439-457] and their OE and OBs examined with antibodies to HSP70 6-10.5 weeks postlesion. Lesioned OE showed significantly increased 2A4 (+) ORN densities but no alteration of 2A4 (+) ORN zonal distribution. The OBs of lesioned animals showed marked expansions of 2A4 (+) ORN bulbar projections, with 2-15-fold increases in numbers of glomeruli showing 2A4 (+) axons, and projection expansions were greater in animals maintained on chronic food restriction prior to lesioning. Examination of archival 5-month post-MeBr lesion material indicates that altered projection patterns are maintained. |
7(0,0,1,2) |