Electrical signal propagated across acupoints along Foot Taiyang Bladder Meridian in rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the electrical signals propagated along Foot Taiyang Bladder Meridian (BL) in a rat model.</p><p><b>METHODS</b>The experiments were performed on Dark-Agouti (DA), DA.1U and Sprague Dawley (SD) rats. The antidromic electrical stimulation was applied on the nerve innervating "Pishu" (BL 20) to mimic the acupoint electro-acupuncture (EA). The activities recording from adjacent nerve innervating acupoint "Danshu" (BL 19) or "Weishu" (BL 21) were recorded as indics for acupoint, including the mechanical threshold and discharge rate.</p><p><b>RESULTS</b>After mimic EA on BL 20, C and Aδ units from adjacent BL 19 or BL 21 were sensitized including the decrease in mechanical threshold and increase in discharge rates in DA, DA.1U and SD rats, especially in DA rats. The average discharge rate increased from 2.40±0.26 to 6.06±0.55 and from 1.92±0.42 to 6.17±1.10 impulse/min (P<0.01), and the mechanical threshold decreased from 0.52±0.12 to 0.24±0.05 and from 0.27±0.02 to 0.16±0.01 mmol/L (P<0.01) in C (n=15) and Aδ (n=18) units in DA rats. The net change in discharge rates from C units were 152.5%, 144.7% and 42.4% in DA, DA.1U and SD rats, respectively, among which DA rat's was the highest (P<0.05). In Aδ units, the net change in DA rats were also the highest (221.5%, 139.2% and 49.2% in DA, DA.1U and SD rats).</p><p><b>CONCLUSIONS</b>These results showed that mimic acupoint EA activated adjacent acupoints along BL in three rat strains, which might be related to propagated sensation along meridians (PSM). In addition, DA rats were more sensitive and might be a good model animal for PSM research.</p>

Synchronized reconstruction of posterior cruciate ligament-posterolateral corner injuries / 中华创伤杂志

Objective To introduce the technique and experience in reconstruction of posterior crueiate ligament-posterolateral comer(PCL-PLC)injuries with only one allograft of Achilles tendon. Methods The instable knees in 12 cases with PCL injury combined with three degree chronic PLC injury were treated with PCL reconstruction under arthroscope and PLC reconstruction through posterolateral arc incision.Single bundle grafts of PCL reconstructions in tibial and femoral tunnels were fixed by resorption screws.Fibular collateral ligament(FCL)and popliteofibular ligament(PFL)were reconstructed with reforming Larson(?)method.All reconstruction grafts only needed one Achilles tendon as donator.Total op- eration time was 130 minutes including 90 minutes of PCL reconstruction and 40 minutes of PLC recon- struction.Gradual weight loading was allowed after six weeks of bracing.Results Follow-up for mean 12 months(5-24 months)indicated that tibial“step off”reduction was 83%(10/12)and posterior drawer test of 0-1~+ 75%(9/12).Dial sign evaluated that normal external rotation angle was 75%(8/12).Nor- real varus stress test at 30?knee flexion accounted for 83%(10/12).Scores of Lysholm,Tegner and HSS were 90.5,5.1 and 84.5,respectively(P＜0.01=.Conclusion Synchronized reconstruction of PCL and PLC injuries with only one Achilles tendon can obtain satisfactory clinical result,with less expense and shorter operation time.

Effects of electrical stimulation of the dorsal cutaneous branches of spinal nerves on the discharge activity of remote mechanoreceptive units in rats / 生理学报

The method of isolating filaments of the dorsal cutaneous branches was used to observe the effects of antidromic electrical stimulation of the spinal nerves on the discharge of remote A delta and C mechanoreceptive units in rats. Seventy-nine mechanoreceptive units were recorded from the T12 nerve filaments after stimulation of the dorsal cutaneous branches of T9 spinal nerve. It was found that the discharge frequency of 59.3% (16/27) A delta-units and 71.2% (37/52) C-units significantly increased during 90-120 s after the stimulation. Sixty-four mechanoreceptive units were recorded from the T12 nerve filaments after stimulation of the dorsal cutaneous branches of T8 spinal nerves. The discharge frequency of 47.8% (11/23) A delta-units and 36.6% (15/41) C-units significantly increased during 120-150 s after the stimulation. In addition, the threshold of the majority of these mechanoreceptors (78.3%, 18/23) decreased after the stimulation. The results suggest that antidromic electrical stimulation of the dorsal cutaneous branches of spinal nerves leads to sensitization of A delta and C mechanoreceptive units of the remote peripheral nerve endings, which results in an increase in afferent discharge of these units.

Changes in mechano-receptive properties of Abeta-fiber induced by antidromical electrical stimulation of the cutaneous nerve from adjacent spinal segment / 生理学报

The purpose of the present study was to observe whether primary afferent Abeta-fiber is involved in the information transmission between peripheral terminals of adjacent dermatomes. The dorsal cutaneous nerve branches of spinal nerves from T(8) to T(12) segments were cut proximally. One peripheral stump end of the cut nerves was dissected into a few filaments for the examination of mechanoreceptive properties of single Abeta-fibers and their discharges were observed while the other end was stimulated antidromically. Fifty Abeta-units were recorded in forty-two intact rats. After an electrical stimulation (0.45 mA, 0.1 ms, 20 Hz, for 10 s) was delivered to the stimulated nerve, the size of the receptive field of 60.6% (n=33) Abeta-fibers extended. The mean area of receptive fields of all examined units enlarged from 8.94+/-6.51 mm(2) to 20.34+/-16.17 mm(2) (P<0.01) and the shapes of the receptive fields of 81.8% (n=20) units changed from a dot, round or ellipse with its long axis in parallel with the longitudinal axis of the body to an oblique ellipse with the longitudinal axis of the body. The mechanoreceptive threshold of 68.0% (n=50) units decreased with a reduction in mean threshold from 2.37+/-1.24 to 2.29+/-1.24 mN (P<0.05). The duration of these changes in mechano-receptive properties increased from 52.23+/-9.27 to 56.93+/-15.76 min. Meanwhile, increasing discharge was found in 50.0% (n=50) units but lasted only for 1.52+/-0.46 min. The changes in mechanoreceptive properties appeared simultaneously with discharge changes but had longer duration than that of discharge change (P<0.01). Discharges changes usually appeared in those units with the changes in mechanoreceptive properties following an antidromical electrical stimulation of adjacent spinal segment. These results suggest that low-threshold mechanoreceptive Abeta-fibers are affected by antidromical electrical stimulation of the cutaneous nerve from an adjacent spinal segment, indicating that information transmission occurs between the two endings of peripheral afferent nerves from adjacent spinal segments without any involvement of the central nervous system, and that Abeta-fibers are involved in the process of information transmission between peripheral terminals from adjacent spinal segments.