OBJECTIVE: To observe the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on the sleep quality and nocturnal heart rate variability (HRV) in patients with primary insomnia. METHODS: Twenty-one patients with primary insomnia were included. Using SDZ-ⅡB electric acupuncture apparatus, Xin (CO₁₅) and Shen (CO₁₀) were stimulated with disperse-dense wave, 4 Hz/ 20 Hz in frequency, (0.2±30%) ms of pulse width and tolerable intensity. Electric stimulation was given once every morning and evening of a day, 30 min each time, for 4 weeks totally. Before and after treatment, the score of Pittsburgh sleep quality index (PSQI), objective sleep structure (total sleep time [TST], sleep latency [SL], wake after sleep onset [WASO], sleep efficiency [SE], the percentages of non-rapid eye movement period 1, 2, 3, and the percentage of rapid eye movement period to TST [N1%, N2%, N3%, REM%] ) and nocturnal HRV (high frequency [HF], low frequency [LF], the ratio of LF to HF [LF/HF], standard deviation for the normal RR intervals [SDNN], squared root of the mean sum of squares of differences between adjacent intervals RR [RMSSD], the percentage of adjacent RR intervals with differences larger than 50 ms in the entire recording [PNN50%], the mean of sinus RR intervals [NNMean] ) were compared in the patients separately. RESULTS: After treatment, the score of each item and the total score of PSQI and SL were all reduced as compared with those before treatment (P<0.01, P<0.001); SE, N3%, LF, HF, LF/HF, SDNN, NNMean and RMSSD were all increased compared with those before treatment (P<0.001, P<0.01). CONCLUSION The taVNS improves the sleep quality and objective sleep structure in patients with primary insomnia, which is probably related to the regulation of autonomic nervous functions.
Heart Rate/physiology* ; Humans ; Sleep/physiology* ; Sleep Initiation and Maintenance Disorders/therapy* ; Vagus Nerve ; Vagus Nerve Stimulation

To determine the role of vagi in heart rate variability, conscious rabbits were employed and electrocardiogram was recorded under conditions of bilateral vagi intact, unilateral vagotomy, and bilateral vagotomy. The variability of RR intervals (RRI) was analyzed using power spectrum and approximate entropy (ApEn). The results showed that the values of high frequency power (HF) component, low frequency power (LF) component and ApEn in animals with bilateral vagi intact were the highest, but the LF/HF ratio was the lowest; unilateral vagotomy decreased ApEn, right vagotomy increased LF/HF ratio but left vagotomy did not; the LF/HF ratio increased while ApEn decreased significantly in animals with bilateral vagotomy. It is suggested that the variability of RRI is mainly regulated by the vagi and the role of right vagi is more important than that of the left. When measuring heart rate variability, the results obtained with conventional method are consistent with those with nonlinear method.
Animals ; Entropy ; Heart Rate ; physiology ; Male ; Rabbits ; Vagus Nerve ; physiology

Animals ; Electric Stimulation ; Hippocampus ; physiology ; Male ; Nerve Endings ; physiology ; Rats ; Rats, Sprague-Dawley ; Vagus Nerve ; physiology

AIMTo investigate the influence of the vagus nerve on the electrophysiological properties in the Mauthner cell soma and the relationship between soma and viscus.

METHODSThe microelectrode recording technique was used to explore the electrophysiological properties in the Mauthner cell when stimulating the right vagus.

RESULTSAt lower stimulation strength a graded and compound excitatory postsynaptic potentials (EPSP), formed by two components with lower amplitude, were recorded on the Mauthner cell in a crucian carp. As the intensity of stimulus increased, the amplitude became larger and lasting time longer. With the stimulations high enough, action potentials (AP) were evoked on the EPSP.

CONCLUSION(1) Action potential can be induced on M cell by a direct stimulation on vagus nerve, which is in controversy with previous reports. (2) The neural pathway projecting from vagus to M cell is composed of a set of neuronal chains with excitatory and/or inhibitory members, the activation of M cell depends on the relationship between excitatory and inhibitory neuron.

Animals ; Carps ; physiology ; Excitatory Postsynaptic Potentials ; physiology ; Microelectrodes ; Neurons ; physiology ; Vagus Nerve ; physiology

OBJECTIVETo observe the effect of vagal stimulation of different frequencies on heart rate and heart rate variability in the toads.

METHODSThe animals were prepared to be models of isolated heart with right vagosympathetic trunks, then the nerves stimulated by different frequencies. Collected the electrocardiogram of isolated hearts and analyzed the data with HRV software.

RESULTSSince the effect of sympathetic nerve had been diminished, vagal stimulation resulted in HR being markedly attenuated (P < 0.01), SDNN and RMSSD being significantly increased (P < 0.01). There was no significant difference in different levels of frequency. Contrast to group control, HR,SDNN and RMSSD each changed clearly. At the frequency of 0.2 Hz, HF increased markedly (P < 0.01), and LF/HF decreased obviously (P < 0.05) in group P + P. While at the frequency of 0.8 Hz, HF and LF/HF were both around the level of pre-stimulation.

CONCLUSIONThese findings suggest that in the certain electrical stimulation frequency range, the effect of vagal on HR increases along with the frequency. Without the effect of sympathetic nerve, the modulation of vagal to HR and HRV may have different ways.

Animals ; Bufonidae ; physiology ; Electric Stimulation ; Female ; Heart Rate ; physiology ; In Vitro Techniques ; Male ; Vagus Nerve ; physiology

OBJECTIVE: To explore the modulation of transcutaneous auricular vagus nerve stimulation (taVNS) on default mode network (DMN) in patients with primary insomnia (PI). METHODS: A total of 22 PI patients (one patient dropped off and two patients were excluded) were included and treated with taVNS. The bilateral auricular points of Xin (CO₁₅) and Shen (CO₁₀) were selected and treated with disperse-dense wave at frequency of 4 Hz/20 Hz, the intensity was based on the patient's tolerance. taVNS was given once in the morning and once in the evening for 30 minutes each time. The treatment lasted for at least 5 days a week for 4 weeks. At the same time, 16 healthy subjects matched with gender and age were recruited. The Pittsburgh sleep quality index (PSQI) score was evaluated before and after treatment in PI patients. The resting-state functional magnetic resonance imaging (rs-fMRI) data of PI patients before and after treatment and healthy subjects at baseline period were collected to observe the effect of taVNS on the functional connection (FC) between posterior cingulate cortex (PCC) and whole brain. RESULTS: After treatment, the total score of PSQI in PI patients was lower than that before treatment (P<0.01). Compared with healthy subjects, the FC of the left PCC was increased either with the left orbital superior frontal gyrus or with left middle frontal gyrus (P<0.001), and the FC between right PCC and left middle frontal gyrus was increased in PI patients before treatment (P<0.001). Compared before treatment, the FC between left PCC and left middle frontal gyrus was decreased (P<0.05), and the FC of the right PCC was decreased either with the right medial prefrontal cortex or with the left middle frontal gyrus in PI patients after treatment (P<0.001, P<0.01). CONCLUSION taVNS can modulate the FC between anterior and posterior DMN, and between DMN and cognitive control network of PI patients, which may be one of the brain effect mechanisms of taVNS in the treatment of PI patients.
Brain/physiology* ; Default Mode Network ; Humans ; Magnetic Resonance Imaging/methods* ; Sleep Initiation and Maintenance Disorders/therapy* ; Vagus Nerve ; Vagus Nerve Stimulation/methods*

Vocal cord paralysis is a comlex disorder which may result from numerous causes. It is often associated with trauma, disease in adjacent tissue, or a generalized neuroligical disorder. Laryngeal EMG is a useful technique for vocal cord paralysis. However it has not been used due to the uncertainties of normal human vocal cord physiology and the technical difficulties in performing these studies. We investigated the pathophysiology of vocal cord paralysis with laryngeal electromyography(LEMG). We studied 20 patients with idiopathic vocal cord paralysis. 6 patients were denervated in the cricothyroid(CT) and 6 patients in the thyroarytenoid(TA), and 3 patients in both CT and TA muscles. These indicated superior laryngeal neuropathy, recurrent laryngeal neuropathy, and proximal laryngeal or vagus neuropathy, respectively. LEMG proved to be a safe and effective procedure in the diagnosis of laryngeal neuropathy, and make it possible to use electromyography as a routine procedure in diagnosis laryngeal paralysis.
Diagnosis ; Electromyography* ; Humans ; Muscles ; Physiology ; Vagus Nerve Diseases ; Vocal Cord Paralysis* ; Vocal Cords*

A 17-year-old high school student presented with a history of habitual faintings. On 24-hour Holter monitoring, cardiac asystoles were recorded, the longest lasting approximately 7 or 8 seconds during venipuncture procedures. The asystole associated with venipuncture demonstrated the cardioinhibitory effects of vasovagal reaction with blood-injury phobia. He also had a positive response during head-up tilt test showing hypotension and relative bradycardia after intravenous isoproterenol injection. After administration of oral beta blocker, he did not show further or recurrent cardiac asystole during blood injury procedure on electrocardiographic examination. Venipuncture is the most common invasive medical procedure performed in hospital settings. While venipuncture is considered to be reasonably safe, serious complication may occur even when only a small volume of blood is withdrawn. Therefore, medical personnel should be prepared to provide appropriate care.
Adolescence ; Case Report ; Heart Arrest/etiology* ; Human ; Male ; Phlebotomy/psychology* ; Recurrence ; Syncope/etiology ; Vagus Nerve/physiology*

Animals ; Cardiac Electrophysiology ; Heart Atria ; innervation ; physiopathology ; Humans ; Vagus Nerve ; physiology

Autonomic nervous system plays an important role in the regulation of mammalian heart, and it is divided into the sympathetic and parasympathetic (vagal) subsystems. The parasympathetic (vagal) control of the atria involves modulation of chronotropic, dromotropic and inotropic activities, but the role of the parasympathetic innervation of the ventricles is still unclear. There is a common misconception that the sympathetic nerves innervate all over the heart; while the parasympathetic nerves only innervate the superventricular part of the heart, but not the ventricles. Recent evidence indicates that the cholinergic innervation of the left ventricle is functionally very important in some mammalian species. The present article reviews the evidence of vagal control in the ventricles from the anatomy and histochemistry, molecular biology, and function areas. Additionally we overview the vagal (muscarinic) regulation of cardiac contractile function and its signal transduction.
Animals ; Heart Ventricles ; anatomy & histology ; innervation ; metabolism ; Humans ; Myocardial Contraction ; physiology ; Receptors, Muscarinic ; metabolism ; Signal Transduction ; physiology ; Vagus Nerve ; physiology