A hypothalamo-midbrain-medullary pathway involved in the inhibition of the respiratory chemoreflex response induced by potassium cyanide in rodents

Abstract

To cite this version:Tabinda Zafar, Charly Brouillard, Laurence Lanfumey, Caroline Sévoz-Couche. A hypothalamomidbrain-medullary pathway involved in the inhibition of the respiratory chemoreflex response induced by potassium cyanide in rodents.Neuropharmacology, Elsevier, 2017Elsevier, , 10.1016Elsevier, /j.neuropharm.2017 Accepted Manuscript A hypothalamo-midbrain-medullary pathway involved in the inhibition of the respiratory chemoreflex response induced by potassium cyanide in rodents This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Rostral cuneiform nucleus and the defence reaction: Direct and indirect midbrain–medullary 5‐HT mechanisms in baroreflex inhibition

“…Previously we showed that the baroreflex inhibition induced by the dorsolateral PAG involved the activation of NTS 5‐HT 3 receptors (Bernard et al, 2008; Comet et al, 2004, 2005; Sévoz‐Couche et al, 2003). Both the microinjection of granisetron into the NTS and the use of mice lacking the 5‐HT 3 receptor prevented dorsolateral PAG‐induced inhibition of chemoreflex responses (Zafar et al, 2018). In the same manner, the cuneiform‐induced baroreflex inhibition was prevented by the blockade of NTS 5‐HT 3 receptors with granisetron and was also not observed in 5‐HT 3 receptor knockout mice.…”

“…Anaesthetized animals were placed in a stereotaxic frame with the head fixed in the flat skull position. The size of the samples was based on previous experiments (Bernard et al, 2008; Netzer et al, 2011; Zafar et al, 2018). Briefly, rostral cuneiform disinhibition was caused by left microinjection of bicuculline in rats (50 pmol per 50 nl, n = 30, n = 6 in each of 5 groups: [i] B3 muscimol, [ii] B3 8‐OH‐DPAT, [iii] B3 saline, [iv] NTS granisetron, and [v] NTS saline) and mice (25 pmol per 25 nl, n = 6 WT and n = 6 5‐HT 3 knockout animals).…”

“…Anaesthetized animals were placed in a stereotaxic frame with the head fixed in the flat skull position. The size of the samples was based on previous experiments (Bernard et al, 2008;Netzer et al, 2011;Zafar et al, 2018). Briefly, rostral cuneiform disinhibition was caused by left microinjection of bicuculline in rats…”

“…"+" indicates excitatory effect; "−" indicates inhibitory effect by the dorsolateral PAG involved the activation of NTS 5-HT 3 receptors (Bernard et al, 2008;Comet et al, 2004Comet et al, , 2005Sévoz-Couche et al, 2003). Both the microinjection of granisetron into the NTS and the use of mice lacking the 5-HT 3 receptor prevented dorsolateral PAG-induced inhibition of chemoreflex responses (Zafar et al, 2018).…”

Mapping of afferent and efferent connections of phenylethanolamine N‐methyltransferase‐expressing neurons in the nucleus tractus solitarii

“…The nucleus tractus solitarii (NTS) receives visceral sensory information and integrates these information to orchestrate autonomic functions such as blood pressure, 1 breathing 2 and gut motility. 3 The NTS not only integrates information from peripheral receptors, but also receives inputs from central nervous systems, such as brainstem, 4 hypothalamus, 5 and limbic system. 6 Meanwhile, NTS neurons extend their axons to numerous brain regions, 7 , 8 , 9 endowing the NTS with the remarkable ability to modulate multiple physiological functions.…”