Figure 1.
The two intertwined rings corresponding to different type of temporal processing.
The VSA ring (in blue) corresponds to high fidelity evoked processing and the PTF ring (in red) corresponds to more spontaneous processing more independent of input action potentials timing (from [3]). Cortical regions sampled by the Allen Institute for Brain Sciences ([7]) are represented by spheres colored like their respective rings. Points in sulci are not visible.
Figure 2.
Differential distribution of gene expression: CA analysis.
a) Dimensions 1 and 2 as extracted by a CA performed on the 394 regions and the 938 genes. The dots represent the factor scores for the regions; each dot is colored in red or blue depending on the represented region localization within (respectively) PTF or VSA. The eigenvalue of Dimension 1 (λ1 = 4.59–03) represents 29% of the total variance, The eigenvalue of Dimension 2 (λ2 = 1.51–03) represents 9% of the total variance. b) The localization of the cortical regions on the brain with PTF and VSA rings colored in, respectively, dark red and dark blue. Light red dots represent regions with significant negative factor scores (BT<–2.00) whereas light blue dots represent regions with significant positive factor scores (BT>2.00).
Figure 3.
DiCA analysis: regions factor scores histogram.
We plot the histogram of the factor score values–obtained for the 394 regions by the DiCA analysis–as a function of the number of regions a priori assigned to the VSA (blue) or the PTF (red) ring.
Figure 4.
Heatmap representing the correlations between the 938 genes used in DiCA.
The correlation coefficients between genes were computed using all 394 regions. The genes are ordered according to their positions on the dimension extracted by DiCA. Red to magenta colors denote strong positive correlations whereas green denotes a strong negative correlation. The genes are clearly organized into two blocks that are related to the gene differential expression for the two rings.
Figure 5.
Bootstrap ratios for the genes for the Dimension extracted by DiCA.
A very large proportion (i.e., 66.5%) of the genes are significant with |BT|>4.00. This indicates that the expression of most genes differ significantly between regions.
Table 1.
The 161 genes coding for proteins forming ionic channels or involved in neurotransmitter release.
Figure 6.
Map of the bootstrap ratios for the 161 genes, analyzed with DiCA, grouped per family and per class of neuronal function.
In blue are represented genes with significant positive bootstrap ratios (BT>4.00) associated with the VSA ring and in red genes with significant negative bootstrap ratios (BT<–4.00) associated with the PTF ring. For each family, extreme genes are identified. These genes are the most preferentially expressed in either VSA or PTF.
Figure 7.
Scatter plot of the gene factor scores of the discriminant dimension extracted by the DiCA analyses performed on the 161 genes measured on Specimens H0352001 (horizontal) and H0352002 of ABA.
Each dot represents one of the 161 genes. The coefficient of correlation is equal to .90 (r2 = .81, p<.001).
Figure 8.
Example of cortical mapping of gene expression with extreme bootstrap ratios in PTF or VSA.
Top. Cortical mapping of the expression of the 4 SCN genes with the highest bootstrap ratios in PTF or VSA: each dot represents one of the 394 cortical regions used in the analysis. The color depends upon the a priori assignment of each region the VSA-ring (in blue) to the PTF-ring (in red). The size of a dot is proportional to the expression of the gene under consideration for the cortical region represented by this dot. Bottom. For each gene, we plot the histogram of the number of regions as a function of gene expression intensities for the VSA (blue) and PTF (red) rings.
Figure 9.
Summary of the temporal properties of proteins that most differentiate between the two rings and their correspondence with the preferred information processing modes of the rings.