Figure 7. Electrically coupled homotypic locus coeruleus (LC) subnetworks.

(A) In two electrical connections between LC neurons, comparing observed ratio (chain/non-chain pattern) vs the ratios predicted by Model 1 (random connectivity), Model 2 (cell-type-specific), and Model 3 (cell type and spatial-specific) suggests a chain-like rule dictating electrical connections. (B) In three electrical connections between LC neurons, observed ratio (chain/non-chain pattern) vs. the ratios predicted by Model 1 (random connectivity), Model 2 (cell-type-specific), and Model 3 suggests a chain-like rule dictating electrical connections. Error bars are standard deviations estimated by bootstrap method. ***p≤0.001, *p<0.05. (C) A sagittal view of the LC with predominant cell types for each subdivision (adopted from Loughlin et al., 1986) and the proposed electrically coupled homotypic subnetworks in the LC. Spindle-shaped: fusiform cell; round-shaped: multipolar cells. Each electrical connection form between cell pairs of same type and each connected pair is connected with each other like a chain within each LC subregion. A: anterior; P: posterior; V: ventral; D: dorsal.