Laser ablation of Dbx1 neurons in the pre-Bötzinger complex stops inspiratory rhythm and impairs output in neonatal mice.
Bottom Line: To understand the neural origins of rhythmic behavior one must characterize the central pattern generator circuit and quantify the population size needed to sustain functionality.Breathing-related interneurons of the brainstem pre-Bötzinger complex (preBötC) that putatively comprise the core respiratory rhythm generator in mammals are derived from Dbx1-expressing precursors.These results demonstrate that a single canonical interneuron class generates respiratory rhythm and contributes in a premotor capacity, whereas these functions are normally attributed to discrete populations.
Affiliation: Department of Applied Science, The College of William and Mary, Williamsburg, United States.Show MeSH
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Mentions: In the subsequent ‘detection phase’, a visible wavelength laser scanned the domain and an iterative threshold-crossing algorithm analyzed the image to then draw regions of interest (ROIs) for putative cell targets based on fluorescence brightness. Potential targets were evaluated on the basis of shape to differentiate cell bodies from auto-fluorescent debris, and to reject the fluorescence from dendrites and neuropil whose somata were detectable in adjacent focal planes (Wang et al., 2013) (Figure 1—figure supplement 2). The map of ROIs for validated cell targets was retained at each focal plane (Figure 1C—figure supplements 1B and 2, red ROIs). Potential targets that did not meet these criteria were discarded (but displayed for demonstration purposes in Figure 1C and Figure 1—figure supplements 1B and 2, blue ROIs). Target detection was repeated at 10-µm increments through the z-axis and the final three-dimensional map of targets was stored in memory (Figure 1D). Typically, we detected 26–50 Dbx1 neurons per focal plane per side (Figure 1—figure supplement 3) for a total average number of 705 targets in the preBötC (SD 119, SEM 59, range: 548 to 802, n = 8 slices).
Affiliation: Department of Applied Science, The College of William and Mary, Williamsburg, United States.