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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

DON microinjection within the central pattern generator of swallowing (SwCPG) inhibited rhythmic swallowing triggered by SLN or ST stimulation in a dose depend manner.Time course of the effects of various doses of DON: 570ng/kg bw (10 trials; A), 150ng/kg bw (10 trials; B), 60ng/kg bw (10 trials; C) on the number of swallows recorded over 5 minute periods (for 570ng/kg bw and 150ng/kg bw) or over 30 second periods (for 60ng/kg bw). On the right side of A and B, note a focus on the kinetics of DON effect over the first 5 min. Black bars represent the mean value of the control recorded before DON injection (C, 100%). Data are represented as means ± SEM normalized to the control value. Note time course variations according to the doses showing a significant inhibitory effect immediately after DON microinjection for 570ng/kg bw and 150ng/kg bw. At 60ng/kg bw, DON microinjection did not modify rhythmic swallowing triggered by SLN stimulation. D: Comparison of the effects of the three doses of DON during the first 25 minutes after injection. Note the powerful effect of 570ng/kg bw and 150ng/kg bw DON doses. *P<0.05, ** P<0.01, *** P<0.001, **** P<0.0001.
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pone.0133355.g006: DON microinjection within the central pattern generator of swallowing (SwCPG) inhibited rhythmic swallowing triggered by SLN or ST stimulation in a dose depend manner.Time course of the effects of various doses of DON: 570ng/kg bw (10 trials; A), 150ng/kg bw (10 trials; B), 60ng/kg bw (10 trials; C) on the number of swallows recorded over 5 minute periods (for 570ng/kg bw and 150ng/kg bw) or over 30 second periods (for 60ng/kg bw). On the right side of A and B, note a focus on the kinetics of DON effect over the first 5 min. Black bars represent the mean value of the control recorded before DON injection (C, 100%). Data are represented as means ± SEM normalized to the control value. Note time course variations according to the doses showing a significant inhibitory effect immediately after DON microinjection for 570ng/kg bw and 150ng/kg bw. At 60ng/kg bw, DON microinjection did not modify rhythmic swallowing triggered by SLN stimulation. D: Comparison of the effects of the three doses of DON during the first 25 minutes after injection. Note the powerful effect of 570ng/kg bw and 150ng/kg bw DON doses. *P<0.05, ** P<0.01, *** P<0.001, **** P<0.0001.

Mentions: The present results, obtained from 30 trials performed on 20 rats, showed that DON microinjections induced a significant dose-dependent decrease in the number of swallows recorded during SLN (or ST) stimulation. At the 570ng/kg dose (10 trials, 9 rats), DON induced immediately a significant powerful decrease of swallows and this inhibition persisted during 43.35 ± 9.71min [Figs 5A and 6A, Table 1]. The maximal effects of DON occurred after 6s and persisted during the 20 first minutes (68.4 ± 8.76% to 48.18 ± 11.5%, P < 0.0001 and P < 0.001). At the 150ng/kg dose (10 trials, 6 rats), DON immediately induced a significant powerful decrease of swallows and the inhibition persisted during 35.9 ± 4.63min [Fig 6B and Table 1]. The maximal effects occurred immediately after DON microinjections and persisted during 15 first minutes (60.8 ± 9.61% to 46.1 ± 10.3%, P < 0.001). In contrast, DON at the 60ng/kg dose (10 trials, 5 rats), failed to alter swallowing pattern characteristics, therefore this DON dose could be considered as subthreshold in our experimental conditions [Fig 6C and Table 1]. Statistical comparison of the inhibitory effects of DON doses during the first 25 minutes after injection, showed a significant dose-dependent effect (Fig 6D). DON injected within the SwCPG inhibited the rhythmic swallowing pattern, without any variation of either cardiac frequency or respiratory activity (30 trials; 20 rats) (Fig 5B).


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

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

DON microinjection within the central pattern generator of swallowing (SwCPG) inhibited rhythmic swallowing triggered by SLN or ST stimulation in a dose depend manner.Time course of the effects of various doses of DON: 570ng/kg bw (10 trials; A), 150ng/kg bw (10 trials; B), 60ng/kg bw (10 trials; C) on the number of swallows recorded over 5 minute periods (for 570ng/kg bw and 150ng/kg bw) or over 30 second periods (for 60ng/kg bw). On the right side of A and B, note a focus on the kinetics of DON effect over the first 5 min. Black bars represent the mean value of the control recorded before DON injection (C, 100%). Data are represented as means ± SEM normalized to the control value. Note time course variations according to the doses showing a significant inhibitory effect immediately after DON microinjection for 570ng/kg bw and 150ng/kg bw. At 60ng/kg bw, DON microinjection did not modify rhythmic swallowing triggered by SLN stimulation. D: Comparison of the effects of the three doses of DON during the first 25 minutes after injection. Note the powerful effect of 570ng/kg bw and 150ng/kg bw DON doses. *P<0.05, ** P<0.01, *** P<0.001, **** P<0.0001.
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pone.0133355.g006: DON microinjection within the central pattern generator of swallowing (SwCPG) inhibited rhythmic swallowing triggered by SLN or ST stimulation in a dose depend manner.Time course of the effects of various doses of DON: 570ng/kg bw (10 trials; A), 150ng/kg bw (10 trials; B), 60ng/kg bw (10 trials; C) on the number of swallows recorded over 5 minute periods (for 570ng/kg bw and 150ng/kg bw) or over 30 second periods (for 60ng/kg bw). On the right side of A and B, note a focus on the kinetics of DON effect over the first 5 min. Black bars represent the mean value of the control recorded before DON injection (C, 100%). Data are represented as means ± SEM normalized to the control value. Note time course variations according to the doses showing a significant inhibitory effect immediately after DON microinjection for 570ng/kg bw and 150ng/kg bw. At 60ng/kg bw, DON microinjection did not modify rhythmic swallowing triggered by SLN stimulation. D: Comparison of the effects of the three doses of DON during the first 25 minutes after injection. Note the powerful effect of 570ng/kg bw and 150ng/kg bw DON doses. *P<0.05, ** P<0.01, *** P<0.001, **** P<0.0001.
Mentions: The present results, obtained from 30 trials performed on 20 rats, showed that DON microinjections induced a significant dose-dependent decrease in the number of swallows recorded during SLN (or ST) stimulation. At the 570ng/kg dose (10 trials, 9 rats), DON induced immediately a significant powerful decrease of swallows and this inhibition persisted during 43.35 ± 9.71min [Figs 5A and 6A, Table 1]. The maximal effects of DON occurred after 6s and persisted during the 20 first minutes (68.4 ± 8.76% to 48.18 ± 11.5%, P < 0.0001 and P < 0.001). At the 150ng/kg dose (10 trials, 6 rats), DON immediately induced a significant powerful decrease of swallows and the inhibition persisted during 35.9 ± 4.63min [Fig 6B and Table 1]. The maximal effects occurred immediately after DON microinjections and persisted during 15 first minutes (60.8 ± 9.61% to 46.1 ± 10.3%, P < 0.001). In contrast, DON at the 60ng/kg dose (10 trials, 5 rats), failed to alter swallowing pattern characteristics, therefore this DON dose could be considered as subthreshold in our experimental conditions [Fig 6C and Table 1]. Statistical comparison of the inhibitory effects of DON doses during the first 25 minutes after injection, showed a significant dose-dependent effect (Fig 6D). DON injected within the SwCPG inhibited the rhythmic swallowing pattern, without any variation of either cardiac frequency or respiratory activity (30 trials; 20 rats) (Fig 5B).

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