Topological Reorganization of Odor Representations in the Olfactory Bulb
(A) Distribution of factor loadings for three of four factors extracted from MC and IN activity patterns evoked by nine stimuli in one OB (time-averaged between 0 and 768 ms; same experiment as in Figure 4A). Each factor is associated with a group of chemically related stimuli and represents a distinct chemical feature (“long-chain,” “aromatic,” and “basic”).
(B) Three-dimensional reconstructions of the three factors representing long-chain, aromatic, and basic properties. Same experiment and conventions as in Figure 4A. Distance between ticks is 50 μm. Arrows depict regions of dense activity. Orientation is as indicated: anterior to posterior (A–P), medial to lateral (M–L), and dorsal to ventral (D–V).
(C) Average focalities of factors extracted from activity patterns across glomeruli (GL), MCs (MC), and INs (IN). Glomerular activity patterns (raw Ca2+ signal; dataset 1) were time-averaged over 2.4 s; MC and IN activity patterns (TDCa signals) were averaged between 0 and 768 ms (datasets 1 and 2). Conventions as in Figure 4B. A single asterisk (*) indicates p ≤ 0.05; triple asterisks (***) indicate p < 0.001. n.s., not significant.
(D) Three-dimensional reconstructions of pattern components that are not explained by factors (Residual) for three stimuli associated with different factors. Same experiment and conventions as in (B) and Figure 4A.
(E) Average focalities of residual patterns (time-averaged between 0 and 768 ms; datasets 1 and 2). Conventions as in (C) and Figure 4B.