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The Food Contaminant Mycotoxin Deoxynivalenol Inhibits the Swallowing Reflex in Anaesthetized Rats.

Abysique A, Tardivel C, Troadec JD, Félix B - PLoS ONE (2015)

Bottom Line: To better understand DON effects on ingestive behaviour, we have studied its effects on rhythmic swallowing in the rat, after intravenous and central administration.Repetitive electrical stimulation of the superior laryngeal nerve or of the tractus solitarius, induces rhythmic swallowing that can be recorded using electromyographic electrodes inserted in sublingual muscles.Our data show that DON modifies swallowing and interferes with central neuronal networks dedicated to food intake regulation.

View Article: PubMed Central - PubMed

Affiliation: EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, Aix-Marseille University, Marseille, France.

ABSTRACT
Deoxynivalenol (DON), one of the most abundant mycotoxins found on cereals, is known to be implicated in acute and chronic illnesses in both humans and animals. Among the symptoms, anorexia, reduction of weight gain and decreased nutrition efficiency were described, but the mechanisms underlying these effects on feeding behavior are not yet totally understood. Swallowing is a major motor component of ingestive behavior which allows the propulsion of the alimentary bolus from the mouth to the esophagus. To better understand DON effects on ingestive behaviour, we have studied its effects on rhythmic swallowing in the rat, after intravenous and central administration. Repetitive electrical stimulation of the superior laryngeal nerve or of the tractus solitarius, induces rhythmic swallowing that can be recorded using electromyographic electrodes inserted in sublingual muscles. Here we provide the first demonstration that, after intravenous and central administration, DON strongly inhibits the swallowing reflex with a short latency and in a dose dependent manner. Moreover, using c-Fos staining, a strong neuronal activation was observed in the solitary tract nucleus which contains the central pattern generator of swallowing and in the area postrema after DON intravenous injection. Our data show that DON modifies swallowing and interferes with central neuronal networks dedicated to food intake regulation.

No MeSH data available.


Related in: MedlinePlus

Effects of DON intravenous administration on c-Fos immunoreactivity.Representative coronal sections illustrating the c-Fos labeling observed in the brainstem (A, B, C: NTS, D: RVL, E: OL) of I) control rats intravenously treated with NaCl (0.9%) and sacrificed 2h post-treatment, II) rats intravenously treated with DON (3mg/kg bw) and sacrificed 2h post-treatment. III) Quantification of the number of c-Fos immunoreactive nuclei in the brainstem observed in rats treated either with DON (3mg/kg bw) or NaCl (0.9%). *P<0.05, **P<0.01 significantly different from NaCl-treated rats. Box explanation: upper horizontal line of box, 3rd quartile; lower horizontal line of box, 1st quartile; color separation within box, median; upper horizontal bar outside box, max; lower horizontal bar outside box, min. 4V, fourth ventricle; AP, area postrema; cc, central canal; NTS-C, caudal part of the NTS; NTS-R, rostral part of the NTS; NTS-P, postremal division of the NTS; OL, inferior olive; RVL, rostroventral reticular nucleus. Scale bar: 100 μm.
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pone.0133355.g004: Effects of DON intravenous administration on c-Fos immunoreactivity.Representative coronal sections illustrating the c-Fos labeling observed in the brainstem (A, B, C: NTS, D: RVL, E: OL) of I) control rats intravenously treated with NaCl (0.9%) and sacrificed 2h post-treatment, II) rats intravenously treated with DON (3mg/kg bw) and sacrificed 2h post-treatment. III) Quantification of the number of c-Fos immunoreactive nuclei in the brainstem observed in rats treated either with DON (3mg/kg bw) or NaCl (0.9%). *P<0.05, **P<0.01 significantly different from NaCl-treated rats. Box explanation: upper horizontal line of box, 3rd quartile; lower horizontal line of box, 1st quartile; color separation within box, median; upper horizontal bar outside box, max; lower horizontal bar outside box, min. 4V, fourth ventricle; AP, area postrema; cc, central canal; NTS-C, caudal part of the NTS; NTS-R, rostral part of the NTS; NTS-P, postremal division of the NTS; OL, inferior olive; RVL, rostroventral reticular nucleus. Scale bar: 100 μm.

Mentions: Central structures activated in response to intravenous administration of DON were identified using the immune detection of the c-Fos protein. A low basal level of c-Fos positive nuclei was observed in the brainstem of control (NaCl) rats (Fig 4I). DON-treated rats exhibited a significant increases in the number of c-Fos positive nuclei throughout the dorsal vagal complex (DVC) including the nucleus tractus solitarius (NTS) and the area postrema (AP) (Fig 4II). Counts of positive nuclei in the DVC revealed significant increases in the number of c-Fos labeled nuclei in treated animals compared with control animals. In DON-treated rats, we observed a strong c-Fos induction in four sub-regions of the DVC: rostral part, postremal division and caudal part of the NTS, and the AP (Fig 4AII, 4BII and 4CII). In DON treated rats, c-Fos expression levels varied according to the sub-division of the DVC (Fig 4III): i) in the rostral NTS, the mean number of c-Fos positive nuclei per section reached 895.95 ± 121.5 versus 272.85 ± 43.21 in control rats. ii) in the postremal NTS, the number of c-Fos positive nuclei reached 1051.2 ± 72.16 versus 240.45 ± 30.9 in control rats. iii) in the caudal NTS, the number of c-Fos positive nuclei reached 588.5 ± 125.69 versus 143.85 ± 39.8. iiii) in the AP the number of c-Fos positive nuclei reached 190.5 ± 34.86 versus 38.75 ± 14.28 in control rats. The other nuclei positively stained, ie the rostroventral reticular nucleus (RVL) and the inferior olive (OL), exhibited no increase in c-Fos signals in response to DON administration (Fig 4DII, 4EII, and 4III).


The Food Contaminant Mycotoxin Deoxynivalenol Inhibits the Swallowing Reflex in Anaesthetized Rats.

Abysique A, Tardivel C, Troadec JD, Félix B - PLoS ONE (2015)

Effects of DON intravenous administration on c-Fos immunoreactivity.Representative coronal sections illustrating the c-Fos labeling observed in the brainstem (A, B, C: NTS, D: RVL, E: OL) of I) control rats intravenously treated with NaCl (0.9%) and sacrificed 2h post-treatment, II) rats intravenously treated with DON (3mg/kg bw) and sacrificed 2h post-treatment. III) Quantification of the number of c-Fos immunoreactive nuclei in the brainstem observed in rats treated either with DON (3mg/kg bw) or NaCl (0.9%). *P<0.05, **P<0.01 significantly different from NaCl-treated rats. Box explanation: upper horizontal line of box, 3rd quartile; lower horizontal line of box, 1st quartile; color separation within box, median; upper horizontal bar outside box, max; lower horizontal bar outside box, min. 4V, fourth ventricle; AP, area postrema; cc, central canal; NTS-C, caudal part of the NTS; NTS-R, rostral part of the NTS; NTS-P, postremal division of the NTS; OL, inferior olive; RVL, rostroventral reticular nucleus. Scale bar: 100 μm.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4507856&req=5

pone.0133355.g004: Effects of DON intravenous administration on c-Fos immunoreactivity.Representative coronal sections illustrating the c-Fos labeling observed in the brainstem (A, B, C: NTS, D: RVL, E: OL) of I) control rats intravenously treated with NaCl (0.9%) and sacrificed 2h post-treatment, II) rats intravenously treated with DON (3mg/kg bw) and sacrificed 2h post-treatment. III) Quantification of the number of c-Fos immunoreactive nuclei in the brainstem observed in rats treated either with DON (3mg/kg bw) or NaCl (0.9%). *P<0.05, **P<0.01 significantly different from NaCl-treated rats. Box explanation: upper horizontal line of box, 3rd quartile; lower horizontal line of box, 1st quartile; color separation within box, median; upper horizontal bar outside box, max; lower horizontal bar outside box, min. 4V, fourth ventricle; AP, area postrema; cc, central canal; NTS-C, caudal part of the NTS; NTS-R, rostral part of the NTS; NTS-P, postremal division of the NTS; OL, inferior olive; RVL, rostroventral reticular nucleus. Scale bar: 100 μm.
Mentions: Central structures activated in response to intravenous administration of DON were identified using the immune detection of the c-Fos protein. A low basal level of c-Fos positive nuclei was observed in the brainstem of control (NaCl) rats (Fig 4I). DON-treated rats exhibited a significant increases in the number of c-Fos positive nuclei throughout the dorsal vagal complex (DVC) including the nucleus tractus solitarius (NTS) and the area postrema (AP) (Fig 4II). Counts of positive nuclei in the DVC revealed significant increases in the number of c-Fos labeled nuclei in treated animals compared with control animals. In DON-treated rats, we observed a strong c-Fos induction in four sub-regions of the DVC: rostral part, postremal division and caudal part of the NTS, and the AP (Fig 4AII, 4BII and 4CII). In DON treated rats, c-Fos expression levels varied according to the sub-division of the DVC (Fig 4III): i) in the rostral NTS, the mean number of c-Fos positive nuclei per section reached 895.95 ± 121.5 versus 272.85 ± 43.21 in control rats. ii) in the postremal NTS, the number of c-Fos positive nuclei reached 1051.2 ± 72.16 versus 240.45 ± 30.9 in control rats. iii) in the caudal NTS, the number of c-Fos positive nuclei reached 588.5 ± 125.69 versus 143.85 ± 39.8. iiii) in the AP the number of c-Fos positive nuclei reached 190.5 ± 34.86 versus 38.75 ± 14.28 in control rats. The other nuclei positively stained, ie the rostroventral reticular nucleus (RVL) and the inferior olive (OL), exhibited no increase in c-Fos signals in response to DON administration (Fig 4DII, 4EII, and 4III).

Bottom Line: To better understand DON effects on ingestive behaviour, we have studied its effects on rhythmic swallowing in the rat, after intravenous and central administration.Repetitive electrical stimulation of the superior laryngeal nerve or of the tractus solitarius, induces rhythmic swallowing that can be recorded using electromyographic electrodes inserted in sublingual muscles.Our data show that DON modifies swallowing and interferes with central neuronal networks dedicated to food intake regulation.

View Article: PubMed Central - PubMed

Affiliation: EA 4674, Laboratoire de Physiologie et Physiopathologie du Système Nerveux Somato-Moteur et Neurovégétatif, Aix-Marseille University, Marseille, France.

ABSTRACT
Deoxynivalenol (DON), one of the most abundant mycotoxins found on cereals, is known to be implicated in acute and chronic illnesses in both humans and animals. Among the symptoms, anorexia, reduction of weight gain and decreased nutrition efficiency were described, but the mechanisms underlying these effects on feeding behavior are not yet totally understood. Swallowing is a major motor component of ingestive behavior which allows the propulsion of the alimentary bolus from the mouth to the esophagus. To better understand DON effects on ingestive behaviour, we have studied its effects on rhythmic swallowing in the rat, after intravenous and central administration. Repetitive electrical stimulation of the superior laryngeal nerve or of the tractus solitarius, induces rhythmic swallowing that can be recorded using electromyographic electrodes inserted in sublingual muscles. Here we provide the first demonstration that, after intravenous and central administration, DON strongly inhibits the swallowing reflex with a short latency and in a dose dependent manner. Moreover, using c-Fos staining, a strong neuronal activation was observed in the solitary tract nucleus which contains the central pattern generator of swallowing and in the area postrema after DON intravenous injection. Our data show that DON modifies swallowing and interferes with central neuronal networks dedicated to food intake regulation.

No MeSH data available.


Related in: MedlinePlus