Neuroinflammation in the NTS is associated with changes in cardiovascular reflexes during systemic inflammation

Figures

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  Fig. 1. Schematic drawing and representative photo of a punch in the NTS (a) and AVPO (b). Central canal (cc); pyramidal tract (py); spinal trigeminal nucleus (Sp5); area postrema (AP); nucleus tractus solitarius (NTS); lateral ventricle (LV); third ventricle (3 V); anteroventral preoptic region of the hypothalamus (AVPO)

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  Fig. 2. Mean arterial pressure (MAP, a) and heart rate (HR, b) were continuously monitored throughout 180 min in conscious rats that received iv administration of saline (Sal, n = 12) or LPS [1.5 (n = 12) and 2.5 mg kg−1(n = 07)]. Note the acute hypotension and tachycardia after LPS administration. MAP (c) and HR (d) at 3 and 24 h after LPS in comparison with Sal (3 h). Magnitude of low (LF, e) and high frequency (HF, f) components of PI and LF component of SAP (g). *P < 0.05 of LPS-treated group (1.5 and 2.5 mg kg−1) compared with Sal, #P < 0.05 compared with time zero from LPS-treated group of 1.5 and 2.5 mg kg−1. No differenced P > 0.05. were observed between LPS doses tested

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  Fig. 3. Sequences of spontaneous cardiac baroreflex sensitivity of a representative animal from Sal (a) and LPS groups (b), 3 h after LPS or Sal administration. Average values of baroreflex effectiveness index (BEI), and baroreflex gain (c) after Sal (3 h) or LPS (3 and 24 h). *P < 0.05 compared with Sal

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  Fig. 4. Photomicrographs illustrating Iba-1 microglial marker immunostaining (green) and cell nuclei stained with DAPI (blue) from commissural and intermediate NTS (a, b, magnification × 2.5). High magnification from Sal (3 h), LPS (3 h), and LPS (24 h) groups (c) showing the number of microglia cells in the intermediate NTS region (magnification × 10). The inset on the upper right is showing microglial morphology in the intermediate NTS (c, magnification × 20). Central canal (CC)

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  Fig. 5. Average values of microglial number from commissural (a) and intermediate NTS (b) of each experimental group. *P < 0.05 compared with Sal (3 h)

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  Fig. 6. Average of the number of branch, end points, and branch length in the commissural (a) and intermediate NTS (b) of each experimental group. *P < 0.05 compared with Sal (3 h)

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  Fig. 7. Immunoreactivity of GFAP (red) and DAPI (blue) in coronal sections along the commissural (a) and intermediate NTS (b). High magnification from Sal (3 h), LPS (3 h), and LPS (24 h) groups (c) showing no astrocytes activation in the intermediate NTS region

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  Fig. 8. Average values of immunoreactivity intensity within commissural (a) and intermediate NTS (b) of each experimental group

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  Fig. 9. Plasma (a, c) and NTS (b, d) levels of IL-1β and IL-10 respectively from Sal (3 h), LPS (3 h), and LPS (24 h) groups. *P < 0.05 compared with Sal (3 h)

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  Fig. 10. Recordings of PAP, MAP, and HR responses to peripheral chemoreflex activation with i.v. injection of potassium cyanide (KCN, a, b) and phenylbiguanide (PBG, e, f) in one representative Sal (3 h left) and one LPS (3 h) rat (middle). Average values of changes in baseline MAP and HR at 3 and 24 h after LPS administration in response to KCN (c, d) and PBG administration (g, h). *P < 0.05 compared with Sal

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  Fig. 11. Changes in deep body temperature (Tb) in response to injection of saline (Sal) or LPS (a). AVPO levels of IL-1β (b) and IL-10 (c). *P < 0.05 compared with Sal (3 h), #P < 0.05 compared with time zero. The shaded area in gray shows the hypothermia and the blue area shows the fever

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  Fig. 12. Graphical abstract. Representative diagram with findings of the present study observed after lipopolysaccharide (LPS) administration. Interleukin (IL), nucleus tractus solitarius (NTS), and anteroventral preoptic region of the hypothalamus (AVPO)