Vagus Nerve

Our earlier studies demonstrated that representative microbial substances--lipopolysaccharide, peptidoglycan, and poly-inosine: poly-cytosine (poly(I):(C))--increased the spontaneous discharge rates and sensory-evoked responses of isolated locus coeruleus (LC) neurons in a dose- and time-related manner after i.p. injection into rats. We then turned our attention to the mechanism by which microbial substances administered into the peritoneal cavity affect the LC neurons. The involvement of the subdiaphragmatic vagus nerves was examined in this regard since several brain responses to peripherally administered lipopolysaccharide have been found to depend upon the integrity of these nerves. The experiments reported here show that lipopolysaccharide, peptidoglycan, and poly(I):(C) all failed to excite LC neurons after i.p. injection into rats that had previously been subjected to complete transection of the subdiaphragmatic vagus nerves. Furthermore, selective transection of the subdiaph...

The nociceptor TRPA1 is thought to be activated through covalent modification of specific cysteine residues on the N terminal of the channel. The precise mechanism of covalent modification with unsaturated carbonyl-containing compounds is unclear, therefore by examining a range of compounds which can undergo both conjugate and/or direct addition reactions we sought to further elucidate the mechanism(s) whereby TRPA1 can be activated by covalent modification. Calcium signalling was used to determine the mechanism of activation of TRPA1 expressed in HEK293 cells with a series of related compounds which were capable of either direct and/or conjugate addition processes. These results were confirmed using physiological recordings with isolated vagus nerve preparations. We found negligible channel activation with chemicals which could only react with cysteine residues via conjugate addition such as acrylamide, acrylic acid, and cinnamic acid. Compounds able to react via either conjugate or direct addition, such as acrolein, methyl vinyl ketone, mesityl oxide, acrylic acid NHS ester, cinnamaldehyde and cinnamic acid NHS ester, activated TRPA1 in a concentration dependent manner as did compounds only capable of direct addition, namely propionic acid NHS ester and hydrocinnamic acid NHS ester. These compounds failed to activate TRPV1 expressed in HEK293 cells or mock transfected HEK293 cells. For molecules capable of direct or conjugate additions, the results suggest for the first time that TRPA1 may be activated preferentially by direct addition of the thiol group of TRPA1 cysteines to the agonist carbonyl carbon of α,β-unsaturated carbonyl-containing compounds.

There is now strong evidence from animal studies that gut microorganism can activate the vagus nerve and that such activation plays a critical role in mediating effects on the brain and behaviour. The vagus appears to differentiate between non-pathogenic and potentially pathogenic bacteria even in the absence of overt inflammation and vagal pathways mediate signals that can induce both anxiogenic and anxiolytic effects, depending on the nature of the stimulus. Certain vagal signals from the gut can instigate an anti-inflammatory reflex with afferent signals to the brain activating an efferent response, releasing mediators including acetylcholine that, through an interaction with immune cells, attenuates inflammation. This immunomodulatory role of the vagus nerve may also have consequences for modulation of brain function and mood.What is currently lacking are relevant data on the electrophysiology of the system. Certainly, important advances in our understanding of the gut-brain and...

The polyvagal theory describes an autonomic nervous system that is influenced by the central nervous system, sensitive to afferent influences, characterized by an adaptive reactivity dependent on the phylogeny of the neural circuits, and interactive with source nuclei in the brainstem regulating the striated muscles of the face and head. The theory is dependent on accumulated knowledge describing the phylogenetic transitions in the vertebrate autonomic nervous system. Its specific focus is on the phylogenetic shift between reptiles and mammals that resulted in specific changes to the vagal pathways regulating the heart. As the source nuclei of the primary vagal efferent pathways regulating the heart shifted from the dorsal motor nucleus of the vagus in reptiles to the nucleus ambiguus in mammals, a face-heart connection evolved with emergent properties of a social engagement system that would enable social interactions to regulate visceral state.

The facial nerve (CN VII) nerve follows a torturous and complex path from its emergence at the pontomedullary junction to its various destinations. It exhibits a highly variable and complicated branching pattern and forms communications with several other cranial nerves. The facial nerve forms most of these neural intercommunications with branches of all three divisions of the trigeminal nerve (CN V), including branches of the auriculotemporal, buccal, mental, lingual, infraorbital, zygomatic, and ophthalmic nerves. Furthermore, CN VII also communicates with branches of the vestibulocochlear nerve (CN VIII), glossopharyngeal nerve (CN IX), and vagus nerve (CN X) as well as with branches of the cervical plexus such as the great auricular, greater, and lesser occipital, and transverse cervical nerves. This review intends to explore the many communications between the facial nerve and other nerves along its course from the brainstem to its peripheral branches on the human face. Such connections may have importance during clinical examination and surgical procedures of the facial nerve. Knowledge of the anatomy of these neural connections may be particularly important in facial reconstructive surgery, neck dissection, and various nerve transfer procedures as well as for understanding the pathophysiology of various cranial, skull base, and neck disorders.

L'approccio neurofisiologico osteopatico alla lombalgia nel paradigma PNEI  - L'osteopatia può dare un importante contributo al trattamento della lombalgia cronica in quanto terapia manuale volta a comprendere e ad agire sui legami che la zona lombare presenta con il resto dell'organismo, visceri in primis, e dello stile di vita di una persona.

In this editorial we propose an approach for improving brain lymphatic flow in autism through lymphatic drainage massage that is a strategy successfully utilized in a variety of neurological conditions where lymph coming from the brain finds obstacles at the level of deep cervical nodes. We estimate that manual lymphatic massage at the level of deep cervical nodes improves brain lymphatic drainage possibly resulting in decrease of neuroinflammation that is a hallmark of autism. In addition to stimulating lymphatic drainage, we theorize that such an approach may work also as vagus nerve stimulation with the additional benefit of targeting the larynx in a manner similar to that outlined for laryngeal manual therapy. This therapy is utilized for the treatment of dysphonia, and its effects on speech, a function that is typically altered in autism, may contribute to the overall improvement of symptoms. We propose that this type of inexpensive, safe and accessible approach can be beneficial to autistic subjects and constitute a new and promising treatment. We are convinced that the described approach will play a pivotal role in future options for autism treatment, possibly in combination with other therapeutic approaches such as behavioral therapies or nutritional supplementation.

Also discusses Polyvagal theory. The research for this paper was done for Wolfgang "Wilf" Schareck, who teaches a method of gut-oriented breathing and mindfulness. See https://www.breathacademia.com. It is in Turkish, but you can "right click" to translate.

Heart rate variability (HRV) is the temporal beat-to-beat variation in successive RR intervals on an electrocardiographic (ECG) recording and it reflects the regulation of the heart rate (HR) by the autonomic nervous system (ANS). HRV analysis is a noninvasive tool for the assessment of autonomic function that gained momentum in the late 1980s when its clinical relevance as a predictor of mortality was established by a milestone study by Kleiger et al. in patients with postacute myocardial infarction. In the last few decades, the increasing availability of commercial ECG devices offering HRV analysis has made HRV a favorite marker for risk stratification in the setting of cardiovascular disease. The rapid aging of the world population and the growing popularity of HRV have also fueled interest for the prognostic value of HRV in the elderly, outside a specific cardiological context. However, the discussion of HRV measures in the elderly is still very much centered on the rather reductionistic model of sympathovagal balance, with the orthosympathetic and parasympathetic limbs of the ANS exercising opposing effects on the heart via autonomic tone. The expanding application of nonlinear dynamics to medicine has brought to the forefront the notion of system complexity, embedded in the mathematical concepts of chaos theory and fractals, and provides an opportunity to suggest a broader interpretation for the prognostic significance of HRV, especially in the elderly. Although the use of novel indices of HRV may be hampered by practical issues, a more holistic approach to HRV may still be safeguarded if traditional time- and frequency-domain measures are viewed in terms of autonomic modulation. This review focuses on HRV in geriatric populations. It considers studies on the prognostic value of HRV in elderly subjects, discussing the potential confounding effect of erratic rhythm, and concentrates on the conceptual distinction between autonomic tone and autonomic modulation. It also briefly addresses the question of the practicality of ECG recordings and identifies a promising area for future research in the effects of common noncardioactive drugs on HRV.(PACE 2012;00:1–17)

The prevailing view in the literature is that hysterectomy improves the quality of life. This is based on claims that hysterectomy alleviates pain (dyspareunia and abnormal bleeding), and improves sexual response. Since hysterectomy requires cutting the sensory nerves that supply the cervix and/or uterus, it is surprising that the reports of deleterious effects on sexual response are so limited. However, we note that almost all the papers we found reported that some of the women in their studies claim that hysterectomy is detrimental to their sexual response.It is likely that the degree to which a woman’s sexual response and pleasure are affected by hysterectomy would depend not only upon which nerves were severed by the surgery, but also the genital regions whose stimulation the woman enjoys for eliciting sexual response. Since clitoral sensation (via pudendal and genitofemoral nerves) should not be affected by hysterectomy, this surgery would not diminish sexual response in women who prefer clitoral stimulation. However, women whose preferred source of stimulation is vaginal or cervical would be more likely to experience a decrement in sensation and consequently sexual response after hysterectomy, because the nerves innervating those organs -- pelvic, hypogastric and vagus -- are more likely to be damaged or severed in the course of hysterectomy. However, all the published reports of the effects of hysterectomy on sexual response fail to specify the women’s preferred sources of genital stimulation.As discussed in the present review, we believe that the critical lack of information as to the women’s preferred sources of genital stimulation is key to accounting for the discrepancies in the literature as to whether hysterectomy improves or attenuates sexual pleasure.

In this study, we compared the reliability of short-term resting heart rate (HR) variability (HRV) and postexercise parasympathetic reactivation (i.e., HR recovery (HRR) and HRV) indices following either submaximal or supramaximal exercise. On 4 different occasions, beat-to-beat HR was recorded in 15 healthy males (21.5 ± 1.4 yr) during 5 min of seated rest, followed by submaximal (Sub) and supramaximal (Supra) exercise bouts; both exercise bouts were followed by 5 min of seated recovery. Reliability of all HR-derived indices was assessed by the typical error of measurement expressed as a coefficient of variation (CV,%). CV for HRV indices ranged from 4 to 17%, 7 to 27% and 41 to 82% for time domain, spectral and ratio indices, respectively. The CV for HRR ranged from 15 to 32%. Spectral CVs for HRV were lower at rest compared with Supra (e.g., natural logarithm of the high frequency range (LnHF); 12.6 vs. 26.2%; P=0.02). HRR reliability was not different between Sub and Supra (25 v...

This study reports a review of the literature on the structural anatomy of the Vth, VIIth, VIIIth, IXth, and Xth cranial nerves, known to harbor dysfunction syndromes in humans. Because these dysfunctions are hypothesized to be caused by neurovascular conflicts at the root entry/exit zone and the transitional zone between central and peripheral myelinization, this investigation focused on the study and description of this junction. All the cranial nerves, except the optic and olfactory nerves, which are considered to be more a direct expansion of the central nervous system, have a transitional zone between central myelin (coming from oligodendrocytes) and peripheral myelin (produced by Schwann cells). The human studies reported in the literature argue in favor of a dome-shaped transitional zone directed to the periphery. It seems that this junctional region is situated more peripherally in sensory nerves than in motor nerves. The transitional zone is situated very peripherally for t...