Evidence that substance P is a neurotransmitter of baro- and chemoreceptor afferents in nucleus tractus solitarius

Gillis, Richard A.; Helke, Cinda J.; Hamilton, Betty L.; Norman, Wesley P.; Jacobowitz, David M.

doi:10.1016/0006-8993(80)90633-2

Cited by 258 publications

(73 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, we do not feel that this is the case because contralateral vagal afferents also terminate in the area of the mNTS (14,20).…”

Section: Experimental Protocolsmentioning

confidence: 84%

“…However, some vagal afferent input is present owing to crossover of vagal sensory fibers from the contralateral intact vagus nerve (Fig. 1) (4,7,14,20). Moreover, this disadvantage is far outweighed by the advantage of having gastric motility changes produced by selective NTS manipulation and not by contaminating effects of drug diffusion to the adjacent DMV producing direct stimulation of preganglionic gastric-projecting fibers.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

GABA signaling in the nucleus tractus solitarius sets the level of activity in dorsal motor nucleus of the vagus cholinergic neurons in the vagovagal circuit

Herman

Cruz²,

Sahibzada³

et al. 2009

American Journal of Physiology-Gastrointestinal and Liver Physi

View full text Add to dashboard Cite

It has been proposed that there is an "apparent monosynaptic" connection between gastric vagal afferent nerve terminals and inhibitory projection neurons in the nucleus tractus solitarius (NTS) and that two efferent parallel pathways from the dorsal motor nucleus of the vagus (DMV) influence peripheral organs associated with these reflexes (6). The purpose of our study was to verify the validity of these views as they relate to basal control of gastric motility. To test the validity of a direct connection of vagal afferent terminals (known to release L-glutamate) directly impacting second-order projection neurons, we evaluated the effect of GABA A receptor blockade in the area of the medial subnucleus of the tractus solitarius (mNTS) on gastric motility. Microinjection of bicuculline methiodide into the mNTS produced robust decreases in gastric motility (Ϫ1.6 Ϯ 0.2 mmHg, P Ͻ 0.05, n ϭ 23), which were prevented by cervical vagotomy and by pretreatment with kynurenic acid microinjected into the mNTS. Kynurenic acid per se had no effect on gastric motility. However, after GABA A receptor blockade in the mNTS, kynurenic acid produced a robust increase in gastric motility. To test for the contribution of two parallel efferent DMV pathways, we assessed the effect of either intravenous atropine methylbromide or N G -nitro-L-arginine methyl ester on baseline motility and on decreases in gastric motility induced by GABA A receptor blockade in the mNTS. Only atropine methylbromide altered baseline motility and prevented the effects of GABA A receptor blockade on gastric motility. Our data demonstrate the presence of intra-NTS GABAergic signaling between the vagal afferent nerve terminals and inhibitory projection neurons in the NTS and that the cholinergic-cholinergic excitatory pathway comprises the functionally relevant efferent arm of the vagovagal circuit. gastric; vagus; afferent; inhibition; rat THE IMPORTANCE OF THE VAGOVAGAL reflexes in the regulation of gastrointestinal (GI) function has been highlighted in a recent series of articles published under the theme "Musings on the Wanderer: What's New in Our Understanding of Vagovagal Reflexes?" (6, 37). The central nervous system component of this reflex circuit is located in the hindbrain and consists of a sensory nucleus, the nucleus tractus solitarius (NTS), and a motor nucleus, the dorsal motor nucleus of the vagus (DMV). Currently it is thought that signals from sensory receptors in the GI tract are received in the NTS and conveyed to DMV preganglionic vagal nerves (28, 36). These impulses produce functional changes in thoracic and abdominal viscera (28, 36). Critical to conveying sensory signals to vagal efferent impulses are synaptic connections between NTS and DMV neurons. There is considerable evidence that GABAergic neurons are responsible for a significant part of this communication (9, 35). There is also evidence that noradrenergic neurons take part in this communication process (10,11,18,26,29). Both the GABAergic and noradrenergic neurons are considered...

show abstract

“…However, we do not feel that this is the case because contralateral vagal afferents also terminate in the area of the mNTS (14,20).…”

Section: Experimental Protocolsmentioning

confidence: 84%

Section: Discussionmentioning

confidence: 99%

GABA signaling in the nucleus tractus solitarius sets the level of activity in dorsal motor nucleus of the vagus cholinergic neurons in the vagovagal circuit

Herman

Cruz²,

Sahibzada³

et al. 2009

American Journal of Physiology-Gastrointestinal and Liver Physi

View full text Add to dashboard Cite

show abstract

“…Second, hypoxia stimulates ventilation via the activation of the chemosensors of the carotid bodies (Hlastala and Berger, 1996), the afferents of which likely use substance P as neurotransmitter to signal hypoxia to their brainstem targets (Gillis et al, 1980;Kalia et al, 1984;Lindefors et al, 1986;Holtman, 1988). Under mild hypoxia, minute ventilation increases more in C3H than in Tg8 mice.…”

Section: Abnormal Respiratory Regulations In Adult Tg8 Micementioning

confidence: 99%

Altered Respiratory Activity and Respiratory Regulations in Adult Monoamine Oxidase A-Deficient Mice

et al. 2001

View full text Add to dashboard Cite

The abnormal metabolism of serotonin during the perinatal period alters respiratory network maturation at birth as revealed by comparing the monoamine oxidase A-deficient transgenic (Tg8) with the control (C3H) mice (Bou-Flores et al., 2000). To know whether these alterations occur only transiently or induce persistent respiratory dysfunction during adulthood, we studied the respiratory activity and regulations in adult C3H and Tg8 mice. First, plethysmographic and pneumotachographic analyses of breathing patterns revealed weaker tidal volumes and shorter inspiratory durations in Tg8 than in C3H mice. Second, electrophysiological studies showed that the firing activity of inspiratory medullary neurons and phrenic motoneurons is higher in Tg8 mice and that of the intercostal motoneurons in C3H mice. Third, histological studies indicated abnormally large cell bodies of Tg8 intercostal but not phrenic motoneurons. Finally, respiratory responses to hypoxia and lung inflation are weaker in Tg8 than in C3H mice. DL-p-chlorophenyl-alanine treatments applied to Tg8 mice depress the high serotonin level present during adulthood; the treated mice recover normal respiratory responses to both hypoxia and lung inflation, but their breathing parameters are not significantly affected. Therefore in Tg8 mice the high serotonin level occurring during the perinatal period alters respiratory network maturation and produces a permanent respiratory dysfunction, whereas the high serotonin level present in adults alters the respiratory regulatory processes. In conclusion, the metabolism of serotonin plays a crucial role in the maturation of the respiratory network and in both the respiratory activity and the respiratory regulations.

show abstract

“…Several studies have indicated a major role for L-glutamate and the different subtypes of EAA receptors in this neurotransmission (7)(8)(9)(10). There is also evidence in the literature suggesting that substance P also plays an important role in the neurotransmission of the baroreflex afferents in the NTS (11) and may be involved in the processing of the sympatho-excitatory component of the chemoreflex in the NTS (11)(12)(13)(14).…”

Section: Introductionmentioning

confidence: 99%

“…Considering the possible involvement of substance P in the processing of the sympatho-excitatory component of the chemoreflex in the NTS (11)(12)(13)(14), in the present study we evaluated the role of substance P and NK-1 receptors in the processing of the chemoreflex afferents in the lateral commissural NTS of awake rats. To achieve these goals we microinjected substance P into the NTS of awake rats before and after local microinjection of WIN, an NK-1 receptor antagonist, and we also activated the chemoreflex before and after bilateral microinjection of an effective dose of WIN into the lateral commissural NTS of awake rats.…”

Section: Introductionmentioning

confidence: 99%

Blockade of NK-1 receptors in the lateral commissural nucleus tractus solitarii of awake rats had no effect on the cardiovascular responses to chemoreflex activation

Zhang

Bonagamba

Machado

2000

Braz J Med Biol Res

View full text Add to dashboard Cite

The neurotransmission of the chemoreflex in the nucleus tractus solitarii (NTS), particularly of the sympatho-excitatory component, is not completely understood. There is evidence that substance P may play a role in the neurotransmission of the chemoreflex in the NTS. Microinjection of substance P (50 pmol/50 nl, N = 12, and 5 nmol/50 nl, N = 8) into the commissural NTS of unanesthetized rats produced a significant increase in mean arterial pressure (101 ± 1 vs 108 ± 2 and 107 ± 3 vs 115 ± 4 mmHg, respectively) and no significant changes in heart rate (328 ± 11 vs 347 ± 15 and 332 ± 7 vs 349 ± 13 bpm, respectively) 2 min after microinjection. Previous treatment with WIN, an NK-1 receptor antagonist (2.5 nmol/50 nl), microinjected into the NTS of a specific group of rats, blocked the pressor (11 ± 5 vs 1 ± 2 mmHg) and tachycardic (31 ± 6 vs 4 ± 3 bpm) responses to substance P (50 pmol/50 nl, N = 5) observed 10 min after microinjection. Bilateral microinjection of WIN into the lateral commissural NTS (N = 8) had no significant effect on the pressor (50 ± 4 vs 42 ± 6 mmHg) or bradycardic (-230 ± 16 vs -220 ± 36 bpm) responses to chemoreflex activation with potassium cyanide (iv). These data indicate that the activation of NK-1 receptors by substance P in the NTS produces an increase in baseline mean arterial pressure and heart rate. However, the data obtained with WIN suggest that substance P and NK-1 receptors do not play a major role in the neurotransmission of the chemoreflex in the lateral commissural NTS.

show abstract

Evidence that substance P is a neurotransmitter of baro- and chemoreceptor afferents in nucleus tractus solitarius

Cited by 258 publications

References 20 publications

GABA signaling in the nucleus tractus solitarius sets the level of activity in dorsal motor nucleus of the vagus cholinergic neurons in the vagovagal circuit

GABA signaling in the nucleus tractus solitarius sets the level of activity in dorsal motor nucleus of the vagus cholinergic neurons in the vagovagal circuit

Altered Respiratory Activity and Respiratory Regulations in Adult Monoamine Oxidase A-Deficient Mice

Blockade of NK-1 receptors in the lateral commissural nucleus tractus solitarii of awake rats had no effect on the cardiovascular responses to chemoreflex activation

Contact Info

Product

Resources

About