Mother and sibling interactions during the preweaning period influence myelination and impulse propagation of the sensory sural nerve in the adult rat.

To investigate whether mother and sibling interactions during the preweaning period influence the histological and electrophysiological characteristics of the sensory sural nerve (SUn) in the adult rat, litters composed of 1, 3, 6, 9, and 12 male pups (P) were formed and the pups routinely weighed until postnatal day 60 (PND60). At PND9, 3P and 6P litters showed greater body weight than pups without siblings or from 9P or 12P litters, and such differences in weight were maintained until adulthood. Analysis of maternal licking at PND8 and 9 showed that pups from large litters received fewer licks than pups from small size litters. At PND60, SUn of rats from 6P and 9P litters had greater compound action potential (CAP) amplitude and a higher proportion of axons with large myelin thickness than nerves from rats of 1P, 3P, or 12P litters. SUn of heaviest rats from 9P and 12P litters had greater CAP area and myelination than the lightest rats from the same litters. We propose that a complex interplay of sensory, social, and nutritional factors arising from mother and littermate interactions during the preweaning period influence myelination and the propagation of action potentials in the SUn of adult rats.

Heart Rate Variability and Psychometric Analysis in Patients with Hyperactive Heart Fire Syndrome.

Background: Hyperactive heart fire syndrome is characterized by anxiety, insomnia, dream-disturbed sleep, tongue ulcers, heat in the hands, and palpitations. However, syndrome differentiation is often subjective due to a lack of objective, quantifiable variables. Objectives: To identify changes in heart rate variability (HRV) and psychometric analysis in patients with hyperactive heart fire syndrome. Methods: Healthy controls (n = 33) were compared to patients with hyperactive heart fire syndrome (n = 48) from the Integrative University Clinic of the State University of Ecatepec Valley (CIU-UNEVE). Physiological outcome measures included heart rate (HR), the standard deviation of the normal-to-normal heartbeat intervals (SDNN), low (LF) and high frequency (HF) power, and the LF/HF ratio. Psychometric outcome measures included the Athens Insomnia Scale (AIS) and the Hamilton Anxiety Rating Scale (HARS). Results: Compared to controls, hyperactive heart fire patients had higher HR (9.6 ± 2.62%), LF (22 ± 4.21%) and LF/HF ratio (23 ± 3.14%), and lower SDNN (21 ± 2.33%) and HF (18 ± 4.61%). Patients showed increased anxiety, both with somatic (33 ± 11.2%) and psychic symptoms (39 ± 10.5%) with more difficulty falling asleep (47 ± 9.9%) and diurnal impact of sleep (31 ± 9.6%). Conclusion: Hyperactive heart fire patients may have a sympathovagal imbalance due to a reduced parasympathetic tone and/or adominant sympathetic tone, which may be at the origin of the observed symptoms of insomnia and anxiety.

Chronic Undernutrition Differentially Changes Muscle Fiber Types Organization and Distribution in the EDL Muscle Fascicles.

Fiber type composition, organization, and distribution are key elements in muscle functioning. These properties can be modified by intrinsic and/or extrinsic factors, such as undernutrition and injuries. Currently, there is no methodology to quantitatively analyze such modifications. On one hand, we propose a fractal approach to determine fiber type organization, using the fractal correlation method in software Fractalyse. On the other hand, we applied the kernel methodology from machine learning to build radial-basis functions for the spatial distribution of fibers (distribution functions), by dividing into square cells a two-dimensional binary image for the spatial distribution of fibers from a muscle fascicle and mounting on each cell a radial-basis function in such a way that the sum of all cell functions creates a smooth version of the fiber histogram on the cell grid. The distribution functions thus created belong in a reproducing kernel Hilbert space which permits us to regard them as vectors and measure distances and angles between them. In the present study, we analyze fiber type organization and distribution in fascicles (F2, F3, F4, and F5) of the extensor digitorum longus muscle (EDLm) from control and undernourished male rats. Fibers were classified according to the ATPase activity in slow, intermediate, and fast. Then, (x, y) coordinates of fibers were used to build binary images and distribution functions for each fiber type and both conditions. The fractal organization analysis showed that fast and intermediate fibers, from both groups, had a fractal organization within the four fascicles, i.e., the fiber assembly is distributed in clusters. We also show that chronic undernutrition altered the organization of fast fibers in the F3, although it still is considered a fractal organization. Distribution function analysis showed that each fiber type (slow, intermediate, and fast) has a unique distribution within the fascicles, in both conditions. However, chronic undernutrition modified the intra-fascicular fiber type distributions, except in the F2. Altogether, these results showed that the methodology herein proposed allows for analyzing fiber type organization and distribution modifications. On the other side, we show that chronic undernutrition alters not only the fiber type composition but also the organization and distribution, which could affect the muscle functioning, and ultimately, its behavior (e.g., locomotion).

Changes in Heart Rate Variability in Patients with Spleen-Qi Deficiency Syndrome.

Many functional diseases are related to dysautonomia, and heart rate variability has been used to assess dysautonomia. However, heart rate variability has not been studied in Spleen-Qi deficiency syndrome (SQDS). Healthy volunteers (n = 37) and patients with SQDS (n = 67), recruited from the Clinic of the State University of Ecatepec Valley were included in the study. Outcome measures were average heart rate, standard deviation of the normal-to-normal heartbeat intervals, low frequency (LF), high frequency (HF) power, and the LF/HF ratio. Also, intestinal peristalsis, gastrointestinal symptoms (GSs), fatigue, and level of attention were measured. Standard deviation of the normal-to-normal heartbeat intervals (17 ± 2.3%) and HF (14 ± 3.1%) were lower in SQDS patients (17 ± 1.3%) than in healthy volunteers. SQDS patients had higher heart rate, LF power, LF/HF ratio, and fatigue scores (9.6 ± 1.12%, 16 ± 2.1%, 22 ± 3.8%, and 21 ± 4.1%). The fatigue correlated positively with the LF/HF ratio and negatively with HF power. The SQDS group had lower concentration performance (16.2 ± 1.9%) in the d2 test. The intestinal peristalsis showed a reduction (15 ± 1.3%) as compared with control. GS score and peristalsis correlated negatively with HF. Our results suggest that the pathology of SDQS could be associated with a low vagal tone which causes a decrease in peristalsis, increased fatigue, reduced attention, and appearance of GSs.

Electroacupuncture and Curcumin Promote Oxidative Balance and Motor Function Recovery in Rats Following Traumatic Spinal Cord Injury.

Spinal cord injury (SCI) is a condition that puts the patient's life at risk in the acute phase and, during the chronic stage, results in permanent deficits in motor, sensory and autonomic functions. Isolated therapeutic strategies have not shown an effect on this condition. Therefore, this study aimed to evaluate the effects of electroacupuncture (EA) and curcumin, alone or combined, on the oxidative balance, motor function recovery and amount of preserved tissue following a traumatic SCI. Long-Evans rats were divided into five groups: SHAM, SCI, SCI + EA, SCI + Curcumin, and SCI + EA + Curcumin. Nitric oxide was significantly decreased in the Curcumin group; the EA, Curcumin and SCI + EA + Curcumin groups had significantly decreased hydroxyl radical and lipid peroxidation levels. Motor function recovery and the amount of preserved spinal cord tissue were significantly greater in the EA, Curcumin and EA + Curcumin groups. The results show that EA and Curcumin treatment alone or in combination decreased oxidative stress, improved functional motor recovery and increased the amount of preserved spinal cord tissue following a traumatic injury.

Nerve Stimulation: Immunomodulation and Control of Inflammation.

Neuronal stimulation is an emerging field in modern medicine to control organ function and re-establish physiological homeostasis during illness. Transdermal nerve stimulation with electroacupuncture is currently endorsed by the World Health Organization (WHO) and the National Institutes of Health (NIH), and is used by millions of people to control pain and inflammation. Recent advances in electroacupuncture may permit activation of specific neuronal networks to prevent organ damage in inflammatory and infectious disorders. Experimental studies of nerve stimulation are also providing new information on the functional organization of the nervous system to control inflammation and its clinical implications in infectious and inflammatory disorders. These studies may allow the design of novel non-invasive techniques for nerve stimulation to help to control immune and organ functions.

Acupuncture Points and Their Relationship with Multireceptive Fields of Neurons.

In Traditional Chinese Medicine, acupuncture points (APs) have been emphasized as key elements that generate the therapeutic effects of acupuncture. At the spinal cord or supraspinal level, sensory neurons located in the dorsal horn receive an extensive supply of sensory information from skin and muscle receptors through peripheral afferent nerves. The stimulated skin area that influences the activity of a spinal sensory neuron is known as the peripheral receptive field (RF) of that neuron. By considering that a particular AP location involves the activation of one or various RFs, it can be assumed that several sensory central neurons are the site of convergence of the peripheral input generated by acupuncture stimulation. However, stimulation on nonacupoint sites could also activate skin areas with RFs that have been sensitized, and they could be involved in the generation of nonspecific effects of acupuncture, as seen in clinical practice. From the latter, it is suggested that effective APs, and even nonacupoints, are associated with a particular arrangement of RFs, and their study will be useful for understanding the intrinsic mechanisms of acupuncture and for the development and identification of more efficient sites and modes of acupuncture stimulation to evoke optimal therapeutic actions.

Electroacupuncture improves gait locomotion, H-reflex and ventral root potentials of spinal compression injured rats.

This study explored the effect of electroacupuncture stimulation (EA) on alterations in the Hoffman reflex (H-reflex) response and gait locomotion provoked by spinal cord injury (SCI) in the rat. A compression lesion of the spinal cord was evoked by insufflating a Fogarty balloon located in the epidural space at the T8-9 spinal level of adult Wistar male rats (200-250 gr; n=60). In different groups of SCI rats, EA (frequencies: 2, 50 and 100Hz) was applied simultaneously to Huantiao (GB30), Yinmen (BL37), Jizhong (GV6) and Zhiyang (GV9) acupoints from the third post-injury day until the experimental session. At 1, 2, 3 and 4 post-injury weeks, the BBB scores of the SCI group of rats treated with EA at 50Hz showed a gradual but greater enhancement of locomotor activity than the other groups of rats. Unrestrained gait kinematic analysis of SCI rats treated with EA-50Hz stimulation showed a significant improvement in stride duration, length and speed (p<0.05), whereas a discrete recovery of gait locomotion was observed in the other groups of animals. After four post-injury weeks, the H-reflex amplitude and H-reflex/M wave amplitude ratio obtained in SCI rats had a noticeable enhancement (217%) compared to sham rats (n=10). Meanwhile, SCI rats treated with EA at 50Hz manifested a decreased facilitation of the H-reflex amplitude and H/M amplitude ratio (154%) and a reduced frequency-dependent amplitude depression of the H-reflex (66%). In addition, 50 Hz-EA treatment induced a recovery of the presynaptic depression of the Gs-VRP evoked by PBSt conditioning stimulation in the SCI rat (63.2±8.1%; n=9). In concordance with the latter, it could be suggested that 50 Hz-EA stimulation reduced the hyper-excitability of motoneurons and provokes a partial improvement of the locomotive performance and H reflex responses by a possible recovery of presynaptic mechanisms in the spinal cord of experimentally injured rats.

Depressing effect of electroacupuncture on the spinal non-painful sensory input of the rat.

The aim of this study was to explore the effect of electroacupuncture (EA) applied in the Zusanli (ST36) and Sanyinjiao (SP6) points on the N1 component of the cord dorsum potential (CDP) evoked by electrical stimulation of the sural nerve (SU) in the rat. The experiments were performed in 44 Wistar rats (250-300 g) anesthetized with ketamine (100 mg/kg) and xylazine (2 mg/kg). A bilateral laminectomy was performed to expose the L3 to S2 segments of the spinal cord. The SU nerve was exposed and placed on pairs of hook electrodes for electrical stimulation. The N1-CDPs were recorded with three silver-ball electrodes located on the dorsal surface of the L5 to S1 segments. Ipsilateral high and low EA stimulation (100, 2 Hz, 6 mA, 30 min) induced a considerable reduction in the amplitude (45 ± 5.6, 41 ± 6.2%) of the N1-CDP recorded at the L6 segmental level. Recovery of the N1-CDP amplitude occurred approximately 1-3 s after EA. Sectioning of the saphenous and superficial peroneal nerves reduced the depressing effect provoked by the EA stimulation (18.7 ± 1.3, 27 ± 3.8%). Similarly, sectioning of the posterior and anterior tibial, deep peroneal and gastrocnemius nerves partially reduced the effect provoked by EA (11 ± 1.5, 9.8 ± 1.1, 12.6 ± 1.9%). Intravenous picrotoxin (1 mg/kg) also reduced the action of low and high EA (23 ± 4.8, 27 ± 5.2%). It is suggested that EA stimulation depresses non-painful sensory pathways through the activation of specific inhibitory pathways that receive modulatory actions from other sensory and muscle afferent inputs in the rat spinal cord.

Cord dorsum potentials evoked by electroacupuncture applied to the hind limbs of rats.

The longitudinal distribution of the cord dorsum potentials (CDPs) produced by electroacupuncture (EA) stimulation at acupuncture points (APs) located on the hind limbs of rats was analyzed in this study. Single electrical pulses (0.05 ms, 1 Hz) applied to the bladder (BL) and the gallbladder (GB) APs produced CDPs on several spinal segments and were composed of the following four components: an afferent volley, two negative components (N1 and N2), and one positive component (P wave). The larger evoked CDPs differed in their rostrocaudal distributions depending on the stimulated AP site, with those evoked by GB32-33 (at L3) and GB36-37 (at L4) being more caudal than those generated by BL58-59 (at L5) and BL37-38 (at L6). The CDPs produced by stimulating nonacupoints (NAPs) showed similar components and rostrocaudal distributions that were smaller in amplitude than those evoked by stimulating APs. The CDPs produced by stimulating NAPs located on a meridian acupuncture area were similar in amplitude and longitudinal distribution to those produced by stimulating APs. Our results suggest that the specificity of EA stimulation for CDPs responses is mainly related to an activation of meridian pathways associated with peripheral nerve routes rather than to a restricted point specificity of APs.

Endogenous content and release of [(3)H]-GABA and [(3)H]-glutamate in the spinal cord of chronically undernourished rat.

The aim of this study was to determine the effect of chronic undernutrition on the content and release of γ-amino butyric acid (GABA) and glutamate (GLU) transmitters in the rat spinal cord. The release of [(3)H]-GABA and [(3)H]-GLU was determined by radioactive liquid scintillation techniques, and the concentrations of GABA and GLU in spinal cord preparations from control and undernourished young rats (50-60 days old) were measured by reverse-phase HPLC. The GABA and GLU contents in the lumbar spinal dorsal horn (L6 segment) were significantly lower in undernourished rats relative to control rats (22.2 ± 3.7 and 10.7 ± 1.9 %, respectively; P < 0.05). Spinal cord blocks from undernourished animals also showed lower rates of [(3)H]-GABA and [(3)H]-GLU release than controls (27.6 ± 3.5 and 12.8 ± 2.5 %, respectively; P < 0.01). We propose that the decreases in GLU content and release are consistent with a reduced activation of either afferent fibers, spinal glutaminergic neurons, or both. Furthermore, we propose that the decreased content and release of GABA in undernourished animals are related to a depression in pre- and post-synaptic inhibition. In addition, we hypothesize that the reductions in GABA content and release serve as compensatory mechanisms to counterbalance decreases in sensory transmission and GLU content in the spinal cord of the chronically undernourished rat.

The effect of chronic undernourishment on the synaptic depression of cutaneous pathways in the rat spinal cord.

The aim of this study was to determine the effect of chronic undernourishment on the amplitude depression of the first negative component in the cord dorsum potentials (N(1)-CDPs) caused by the conditioning stimulation of sensory cutaneous nerves in the rat spinal cord. Single electrical pulses (1Hz; 2 times threshold) applied to the sural (SU) nerve of control rats (n=14) produced CDPs with a first negative component (N(1)-CDPs) larger in amplitude (14.2±1.3%, p<0.01) than those recorded in chronically undernourished rats (n=14; 3 times threshold). The conditioning stimulation of the SP nerve (4 shocks at 300Hz, 3×T) in the control rats (n=5) evoked a long-lasting (~200ms) depression of the N(1)-CDP (60.2±7.2%). In contrast such depression was smaller in magnitude (42.5±5.7%, p<0.01) and time course (100-120ms) in undernourished rats (n=7). The systemic application of picrotoxin (PTX) reduced, but did not abolish the conditioned depression of the N(1)-CDPs and DRPs in both the control and undernourished rats. By assuming that the depression of the N(1)-CDPs is representative of presynaptic mechanisms, it is proposed that chronic undernourishment influence the activation of presynaptic neuronal pathways that regulate the transmitter release of cutaneous afferent fibers in the spinal cord and such effect could act as a compensatory mechanism that counterbalances the decreased activation of spinal neurons by the reduced afferent input in the rat.