NEUROSCIENCE. For the article “Odor maps of aldehydes and esters revealed by functional MRI in the glomerular layer of the mouse olfactory bulb,” by Fuqiang Xu, Nian Liu, Ikuhiro Kida, Douglas L. Rothman, Fahmeed Hyder, and Gordon M. Shepherd, which appeared in issue 19, September 16, 2003, of Proc. Natl. Acad. Sci. USA (100, 11029-11034; first published September 8, 2003; 10.1073/pnas.1832864100), the authors note that Fig. 1 a and c, the third and fourth panels of Fig. 3a, and the first panel of Fig. 3b were printed incorrectly due to a printer's error. The corrected figures and their legends appear below.
Fig. 1.
Illustration of method for constructing flat maps of fMRI signal in the glomerular layer by using the software program odormapbuilder. (a) Glomerular layer outlined on the anatomical MRI image of the OB. (b) fMRI signal from a typical trial of odor stimulation (heptanal). (c) Superposition of b over a. (Scale bar = 500 μm.) (d) Dorsal-centered map. (e) Ventral-centered map. A, anterior; P, posterior; D, dorsal; M, medial; V, ventral; L, lateral.
Fig. 3.
Comparison of odor submaps defined by different activation levels. (a) The butanal odor map (C4) was divided into lower (L50) and upper (H50) halves by thresholding at the 50th intensity percentile. The H50 was then divided into three levels: I1, 84-100% (highest intensity); I2, 67-83% (medial intensity); and I3, 50-66% (low intensity). (b) Example to demonstrate the analysis of spatial correlation (SCC; see Materials and Methods) between submaps for different odors: A is the I1 submap for C4 and B is the I1 submap for C5. The SCC value is calculated from the total counts of the four different pixel categories, N[1,1], N[1,0], N[0,1], and N[0,0], represented by red, black, green, and blue, respectively. (c) A detailed analysis using SCC with data in Fig. 2a. C4/C5, the comparison between more similar butanal and pentanal maps; Cn/Cn+1, averaged values for all comparisons between the maps of aldehydes with one carbon difference (n = 4, 5, 6, and 7); C4/C8, the comparison between less similar butanal and octanal maps; Cn/Cm, averaged values for all possible comparisons between the maps of aldehydes shown in Fig. 2a (m, n = 4, 5, 6, 7, and 8; m ≠ n). I1∩I1 (black bars), I1∩I2 (red bars), I1∩I3 (green bars), and I1∩L50 (blue bars) are for comparisons of I1 submap of one odorant with the I1, I2, I3, and L50 submap of another odor map, respectively; I2∩I2 (orange bars), the comparisons between the I2 submaps of different odor maps; and I3∩I3 (indigo bars), the comparisons between the I3 submaps of different odor maps. The dotted yellow lines around SCC values of ±0.2 depict the significant correlation at P = 0.01. (d) Tests of reproducibility of activity patterns for aldehydes using the SCC calculation. Reproducibility was assessed from SCC values at three different thresholding levels: top 50% (H50∩H50), top 33% (H33∩H33), and top 16.7% (I1∩I1). The plotted values represent the averaged SCC from pentanal to octanal.