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Paul F Mcculloch - One of the best experts on this subject based on the ideXlab platform.
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restoration of the nasopharyngeal response after bilateral sectioning of the Anterior Ethmoidal Nerve in the rat
Physiological Reports, 2018Co-Authors: Paul F Mcculloch, Karyn M DinovoAbstract:In response to stimulation of the nasal passages with volatile ammonia vapors, the nasopharyngeal reflex produces parasympathetically mediated bradycardia, sympathetically mediated increased peripheral vascular tone, and apnea. The Anterior Ethmoidal Nerve (AEN), which innervates the Anterior nasal mucosa, is thought to be primarily responsible for providing the sensory afferent signals that initiate these protective reflexes, as bilateral sectioning causes an attenuation of this response. However, recent evidence has shown cardiovascular responses to nasal stimulation with ammonia vapors are fully intact 9 days after bilateral AEN sectioning, and are similar to control animals without bilaterally sectioned AENs. To investigate this restoration of the nasopharyngeal response, we recorded the cardiorespiratory responses to nasal stimulation with ammonia vapors immediately after, and 3 and 9 days after, bilateral AEN sectioning. We also processed brainstem tissue for Fos to determine how the restoration of the nasopharyngeal response would affect the activity of neurons in the medullary dorsal horn (MDH), the part of the ventral spinal trigeminal nucleus caudalis region that receives primary afferent signals from the nose and nasal passages. We found 3 days after bilateral AEN sectioning the cardiorespiratory responses to nasal stimulation are partially restored. The bradycardic response to nasal stimulation is significantly more intense 3 days after AEN sectioning compared to Acute AEN sectioning. Surprisingly, 3 days after AEN sectioning the number of Fos-positive neurons within MDH decreased, even though the cardiorespiratory responses to nasal stimulation intensified. Collectively these findings indicate that, besides the AEN, there are alternate sensory pathways that can activate neurons within the trigeminal nucleus in response to nasal stimulation. The findings further suggest trigeminal neuronal plasticity involving these alternate sensory pathways occurs in as few as 3 days after bilateral AEN sectioning. Finally, activation of even a significantly reduced number of MDH neurons is sufficient to initiate the nasopharyngeal response.
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repetitive diving in trained rats still increases fos production in brainstem neurons after bilateral sectioning of the Anterior Ethmoidal Nerve
Frontiers in Physiology, 2016Co-Authors: Paul F Mcculloch, Erik A Warren, Karyn M DinovoAbstract:This research was designed to investigate the role of the Anterior Ethmoidal Nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N=24) were trained to swim and dive through a 5 m underwater maze. Some rats (N=12) had bilateral sectioning of the AEN, others a Sham surgery (N=12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 hrs to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kolliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus the AENs are not required for initiation of the diving response. Other Nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response.
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activation of brainstem neurons in voluntarily diving rats after bilateral sectioning of the Anterior Ethmoidal Nerve
The FASEB Journal, 2015Co-Authors: Paul F Mcculloch, Erik WarrenAbstract:This project was designed to investigate the functional role of the Anterior Ethmoidal Nerve (AEN) during underwater diving in rats. The AEN innervates the nasal passages and is thought to be an im...
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unmyelinated fibers of the Anterior Ethmoidal Nerve in the rat co localize with neurons in the medullary dorsal horn and ventrolateral medulla activated by nasal stimulation
Brain Research, 2009Co-Authors: Michael P Hollandsworth, Karyn M Dinovo, Paul F MccullochAbstract:The Anterior Ethmoidal Nerve (AEN) innervates the nasal passages and external nares, and serves as the afferent limb of the nasopharyngeal and diving responses. However, although 65% of the AEN is composed of unmyelinated fibers, it has not been determined whether this afferent signal is carried by unmyelinated or myelinated fibers. We used the transganglionic tracers WGA-HRP, IB4-HRP, and CTB-HRP to trace the central projections of the AEN of the rat. Interpretation of the labeling patterns suggests that AEN unmyelinated fibers project primarily to the ventral tip of the ipsilateral medullary dorsal horn (MDH) at the level of the area postrema. Other unmyelinated projections were to the ventral paratrigeminal nucleus and ventrolateral medulla, specifically the Botzinger and RVLM/C1 regions. Myelinated AEN fibers projected to the ventral paratrigeminal and mesencephalic trigeminal nuclei. Stimulating the nasal passages of urethane-anesthetized rats with ammonia vapors produced the nasopharyngeal response that included apnea, bradycardia and an increase in arterial blood pressure. Central projections of the AEN co-localized with neurons within both MDH and RVLM/C1 that were activated by nasal stimulation. Within the ventral MDH the density of AEN terminal projections positively correlated with the rostral-caudal location of activated neurons, especially at and just caudal to the obex. We conclude that unmyelinated AEN terminal projections are involved in the activation of neurons in the MDH and ventrolateral medulla that participate in the nasopharyngeal response in the rat. We also found that IB4-HRP was a much less robust tracer than WGA-HRP.
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the Anterior Ethmoidal Nerve is necessary for the initiation of the nasopharyngeal response in the rat
Brain Research, 2006Co-Authors: E J Rybka, Paul F MccullochAbstract:Stimulation of the nasal passages with ammonia vapors can initiate a nasopharyngeal response that resembles the diving response. This response consists of a sympathetically mediated increase in peripheral vascular resistance, parasympathetically mediated bradycardia and an apnea. The current study investigated the role of the Anterior Ethmoidal Nerve (AEN) in the nasopharyngeal response in the rat, as it is thought that the AEN provides the main sensory innervation of the nasal passages. When both AENs were intact, nasal stimulation caused significant bradycardia, hypertension, and apnea and produced Fos label ventrally within the ipsilateral medullary dorsal horn (MDH) and paratrigeminal nucleus just caudal to the obex. This labeling presumably represents activation of second-order trigeminal neurons. When only one AEN was intact, the nasopharyngeal response was slightly attenuated, and a similar pattern of Fos labeling was only seen in the trigeminal nucleus ipsilateral to the intact AEN. The trigeminal labeling contralateral to the intact AEN was significantly reduced. When both AENs were cut, the nasopharyngeal response to nasal stimulation consisted of only a slight apnea and an increase in arterial pressure; the resultant Fos labeling within the trigeminal nucleus was significantly reduced. Cutting both AENs but not stimulating the nasal passages also produced some Fos labeling within the trigeminal nucleus. These findings suggest that a single AEN can provide sufficient afferent input to initiate the cardiorespiratory changes consistent with the nasopharyngeal response. We conclude that the AEN provides a unique afferent contribution that is capable of producing the diving response.
Michael W Panneton - One of the best experts on this subject based on the ideXlab platform.
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trigemino autonomic connections in the muskrat the neural substrate for the diving response
Brain Research, 2000Co-Authors: Michael W Panneton, Paul F MccullochAbstract:Abstract Stimulation of the Anterior Ethmoidal Nerve of the muskrat produces a cardiorespiratory depression similar to the diving response. This includes an apnea, a parasympathetic bradycardia, and a selective increase in sympathetic vascular tone. However, the brainstem circuitry that links the afferent stimulus to the efferent autonomic responses is unknown. We used the anterograde transneuronal transport of the herpes simplex virus (HSV-1), strain 129, after its injection into the Anterior Ethmoidal Nerve to determine the primary, secondary, and tertiary brainstem relays responsible for this cardiorespiratory response. In an effort to check the validity of this relatively untested tracer, we also injected the medullary dorsal horn with biotinylated dextran amine to determine the secondary trigemino-autonomic projections. Approximately 1 μl (6×10 6 PFU) of the HSV-1 virus was injected directly into the Anterior Ethmoidal Nerve of muskrats. After 2–6 days, their trigeminal ganglions, spinal cords and brainstems were cut and immunohistologically processed for HSV-1. Initially (2 days), HSV-1 was observed only in the trigeminal ganglion. After approximately 3 days, HSV-1 was observed first in many brainstem areas optimally labeled between 4 and 4.5 days. In these cases, the ventrolateral superficial medullary dorsal horn, the ventral paratrigeminal nucleus and the interface between the interpolar and caudal subnuclei were labeled ipsilaterally. The nucleus tractus solitarius (NTS), especially its ventrolateral, dorsolateral, and commissural subnuclei were labeled as well as the caudal, intermediate and rostral ventrolateral medulla. Within the pons, the superior salivatory nucleus, the A5 area, the ventrolateral part of the parabrachial nucleus and the Kolliker–Fuse nucleus were labeled. Only after a survival of 4 days or more, the locus coeruleus, the nucleus raphe magnus, the nucleus paragigantocellularis, pars alpha, and the pontine raphe nucleus were labeled. Injections of biotinylated dextran amine were made into the medullary dorsal horn (MDH) in a location similar to that labeled after the viral injections. Fine fibers and terminals were labeled in the same brainstem areas labeled after injections of HSV-1 into the Anterior Ethmoidal Nerve. This study outlines the potential brainstem circuit for the diving response, the most powerful autonomic reflex known. It also confirms the efficacy for using HSV-1, strain 129, as an anterograde transneuronal transport method.
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electrical stimulation of the Anterior Ethmoidal Nerve produces the diving response
Brain Research, 1999Co-Authors: Paul F Mcculloch, Kevin M Faber, Michael W PannetonAbstract:Abstract Stimulation of the upper respiratory tract usually produces apnea, but it can also produce a vagally mediated bradycardia and a sympathetically mediated increase in peripheral vascular resistance. This cardiorespiratory response, often called the diving response, is usually initiated by nasal stimulation. The purpose of this research was to investigate the Anterior Ethmoidal Nerve (AEN) that innervates the nasal mucosa of muskrats (Ondatra zibethicus). Electrical stimulation of the AEN (typically 50 Hz, 100 μs and 500 μA) produced immediate and sustained bradycardia and cessation of respiration similar to that of the diving response. Heart rate (HR) significantly decreased from 264±18 to 121±8 bpm, with a concurrent 4.2±0.9 s apnea, during the 5 s stimulation period. BP decreased from 97.9±4.8 to 91.2±6.4 mmHg. Using estimations from (1) cross-sectional areas of AEN trigeminal ganglion cells labeled with WGA-HRP, and (2) electron microscopic analysis of the AEN, we found that approximately 65% of the AEN is composed of unmyelinated C-fibers. In addition, 72.4% of myelinated fibers from the Nerves that innervate the nasal passages were of small diameter (
Karyn M Dinovo - One of the best experts on this subject based on the ideXlab platform.
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restoration of the nasopharyngeal response after bilateral sectioning of the Anterior Ethmoidal Nerve in the rat
Physiological Reports, 2018Co-Authors: Paul F Mcculloch, Karyn M DinovoAbstract:In response to stimulation of the nasal passages with volatile ammonia vapors, the nasopharyngeal reflex produces parasympathetically mediated bradycardia, sympathetically mediated increased peripheral vascular tone, and apnea. The Anterior Ethmoidal Nerve (AEN), which innervates the Anterior nasal mucosa, is thought to be primarily responsible for providing the sensory afferent signals that initiate these protective reflexes, as bilateral sectioning causes an attenuation of this response. However, recent evidence has shown cardiovascular responses to nasal stimulation with ammonia vapors are fully intact 9 days after bilateral AEN sectioning, and are similar to control animals without bilaterally sectioned AENs. To investigate this restoration of the nasopharyngeal response, we recorded the cardiorespiratory responses to nasal stimulation with ammonia vapors immediately after, and 3 and 9 days after, bilateral AEN sectioning. We also processed brainstem tissue for Fos to determine how the restoration of the nasopharyngeal response would affect the activity of neurons in the medullary dorsal horn (MDH), the part of the ventral spinal trigeminal nucleus caudalis region that receives primary afferent signals from the nose and nasal passages. We found 3 days after bilateral AEN sectioning the cardiorespiratory responses to nasal stimulation are partially restored. The bradycardic response to nasal stimulation is significantly more intense 3 days after AEN sectioning compared to Acute AEN sectioning. Surprisingly, 3 days after AEN sectioning the number of Fos-positive neurons within MDH decreased, even though the cardiorespiratory responses to nasal stimulation intensified. Collectively these findings indicate that, besides the AEN, there are alternate sensory pathways that can activate neurons within the trigeminal nucleus in response to nasal stimulation. The findings further suggest trigeminal neuronal plasticity involving these alternate sensory pathways occurs in as few as 3 days after bilateral AEN sectioning. Finally, activation of even a significantly reduced number of MDH neurons is sufficient to initiate the nasopharyngeal response.
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repetitive diving in trained rats still increases fos production in brainstem neurons after bilateral sectioning of the Anterior Ethmoidal Nerve
Frontiers in Physiology, 2016Co-Authors: Paul F Mcculloch, Erik A Warren, Karyn M DinovoAbstract:This research was designed to investigate the role of the Anterior Ethmoidal Nerve (AEN) during repetitive trained diving in rats, with specific attention to activation of afferent and efferent brainstem nuclei that are part of this reflexive response. The AEN innervates the nose and nasal passages and is thought to be an important component of the afferent limb of the diving response. Male Sprague-Dawley rats (N=24) were trained to swim and dive through a 5 m underwater maze. Some rats (N=12) had bilateral sectioning of the AEN, others a Sham surgery (N=12). Twelve rats (6 AEN cut and 6 Sham) had 24 post-surgical dive trials over 2 hrs to activate brainstem neurons to produce Fos, a neuronal activation marker. Remaining rats were non-diving controls. Diving animals had significantly more Fos-positive neurons than non-diving animals in the caudal pressor area, ventral medullary dorsal horn, ventral paratrigeminal nucleus, nucleus tractus solitarius, rostral ventrolateral medulla, Raphe nuclei, A5, Locus Coeruleus, and Kolliker-Fuse area. There were no significant differences in brainstem Fos labeling in rats diving with and without intact AENs. Thus the AENs are not required for initiation of the diving response. Other Nerve(s) that innervate the nose and nasal passages, and/or suprabulbar activation of brainstem neurons, may be responsible for the pattern of neuronal activation observed during repetitive trained diving in rats. These results help define the central neuronal circuitry of the mammalian diving response.
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unmyelinated fibers of the Anterior Ethmoidal Nerve in the rat co localize with neurons in the medullary dorsal horn and ventrolateral medulla activated by nasal stimulation
Brain Research, 2009Co-Authors: Michael P Hollandsworth, Karyn M Dinovo, Paul F MccullochAbstract:The Anterior Ethmoidal Nerve (AEN) innervates the nasal passages and external nares, and serves as the afferent limb of the nasopharyngeal and diving responses. However, although 65% of the AEN is composed of unmyelinated fibers, it has not been determined whether this afferent signal is carried by unmyelinated or myelinated fibers. We used the transganglionic tracers WGA-HRP, IB4-HRP, and CTB-HRP to trace the central projections of the AEN of the rat. Interpretation of the labeling patterns suggests that AEN unmyelinated fibers project primarily to the ventral tip of the ipsilateral medullary dorsal horn (MDH) at the level of the area postrema. Other unmyelinated projections were to the ventral paratrigeminal nucleus and ventrolateral medulla, specifically the Botzinger and RVLM/C1 regions. Myelinated AEN fibers projected to the ventral paratrigeminal and mesencephalic trigeminal nuclei. Stimulating the nasal passages of urethane-anesthetized rats with ammonia vapors produced the nasopharyngeal response that included apnea, bradycardia and an increase in arterial blood pressure. Central projections of the AEN co-localized with neurons within both MDH and RVLM/C1 that were activated by nasal stimulation. Within the ventral MDH the density of AEN terminal projections positively correlated with the rostral-caudal location of activated neurons, especially at and just caudal to the obex. We conclude that unmyelinated AEN terminal projections are involved in the activation of neurons in the MDH and ventrolateral medulla that participate in the nasopharyngeal response in the rat. We also found that IB4-HRP was a much less robust tracer than WGA-HRP.
Kwan Chul Tark - One of the best experts on this subject based on the ideXlab platform.
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adequacy of local anesthesia on the Anterior Ethmoidal Nerve and the dorsal periosteum for the reduction of the fractured nasal bones
Archives of Plastic Surgery, 2006Co-Authors: Jae Hyun Cho, Hye Kyung Lee, Dong Kyun Rah, Kwan Chul TarkAbstract:Purpose: The nose is the most prominent skeletal feature of the face and is thus prone to frequent injury. Closed reduction of nasal bone fractures can be performed under general or local anesthesia. However, the benefits and the drawbacks in either form of anesthesia chosen are seldom perceived by the surgeon. A retrospective study was performed to assess the differences in the outcome among the two groups subjected to surgery under different type of anesthesia and to introduce our method of local anesthesia and its adequacy. Methods: Two hundred and fifteen patients during a 2-year period were included in the study. 2% Lidocaine mixed with 1:100,000 epinephrine was injected on the Anterior ethmoid Nerve and the periosteum. Assessment factors included intra-operative adequacy of analgesia, post-operative analgesic requirement and functional and aesthetic outcome of surgery. Results: 19 patients were manipulated under general anesthesia and 196 patients were manipulated under local anesthesia on the Anterior Ethmoidal Nerve and dorsal periosteum. No statistically signigicant variable in performance of surgery could be attributed to the mode of anesthesia employed(p>0.05). Four patients experienced complications after reduction. One developed septal deviation and three nasal obstruction. But, no secondary operations were needed. Conclusion: Anterior Ethmoidal Nerve block and dorsal periosteal injection of 2% Xylocaine, combined with topical intranasal 4% lidocaine and epinephrine provided sufficient analgesia comparable to that of general anesthesia.
E J Rybka - One of the best experts on this subject based on the ideXlab platform.
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the Anterior Ethmoidal Nerve is necessary for the initiation of the nasopharyngeal response in the rat
Brain Research, 2006Co-Authors: E J Rybka, Paul F MccullochAbstract:Stimulation of the nasal passages with ammonia vapors can initiate a nasopharyngeal response that resembles the diving response. This response consists of a sympathetically mediated increase in peripheral vascular resistance, parasympathetically mediated bradycardia and an apnea. The current study investigated the role of the Anterior Ethmoidal Nerve (AEN) in the nasopharyngeal response in the rat, as it is thought that the AEN provides the main sensory innervation of the nasal passages. When both AENs were intact, nasal stimulation caused significant bradycardia, hypertension, and apnea and produced Fos label ventrally within the ipsilateral medullary dorsal horn (MDH) and paratrigeminal nucleus just caudal to the obex. This labeling presumably represents activation of second-order trigeminal neurons. When only one AEN was intact, the nasopharyngeal response was slightly attenuated, and a similar pattern of Fos labeling was only seen in the trigeminal nucleus ipsilateral to the intact AEN. The trigeminal labeling contralateral to the intact AEN was significantly reduced. When both AENs were cut, the nasopharyngeal response to nasal stimulation consisted of only a slight apnea and an increase in arterial pressure; the resultant Fos labeling within the trigeminal nucleus was significantly reduced. Cutting both AENs but not stimulating the nasal passages also produced some Fos labeling within the trigeminal nucleus. These findings suggest that a single AEN can provide sufficient afferent input to initiate the cardiorespiratory changes consistent with the nasopharyngeal response. We conclude that the AEN provides a unique afferent contribution that is capable of producing the diving response.