Effect of Electro-Acupuncture on Neuroplasticity of Spinal Cord-Transected Rats

Abstract

BackgroundThis study aimed to evaluate the effects of electro-acupuncture (EA) on neuroplasticity associated with the expressions of neurotrophic factors (NTFs) and their receptors in rats subjected to spinal cord transection (SCT).Material/MethodsA total of 144 rats were randomly divided into 3 groups (n=48 per group): sham-operated group, SCT group, and EA (electro-acupuncture) group. Rats in SCT and EA groups received spinal cord transection at T10–T11 vertebral levels. Then, EA group rats received EA treatment. Reverse transcription polymerase chain reaction was used to detect NTFs and receptors at the mRNA level. In situ hybridization (ISH) and immunohistochemistry (IHC) were used to detect the expression of NTFs and their receptors. Basso, Beattie, Bresnahan (BBB) scores and cortical somato-sensory evoked potentials (CSEP) were evaluated to assess the recovery of motor and sensory functions. We also measured BDA (Biotinylated dextran amine) axonal tracing, CGRP (Calcitonin gene-related peptide), GAP-43 (Growth-associated protein), and synaptophysin immunohistochemistry (IHC).ResultsEA treatment led to obvious improvement in hindlimb locomotor and sensory functions. CNTF, FGF-2, and TrkB mRNA were significantly upregulated, while NGF, PDGF, TGF-β1, IGF-1, TrkA, and TrkC mRNA were concomitantly downregulated in the caudal spinal segment (CSS) following EA. Immunohistochemistry demonstrated an increased number of CGRP fibers, GAP-43, and synaptophysin profiles in the CSS in the EA rats.ConclusionsEA may promote the recovery of neuroplasticity in rats subjected to SCT. This could be attributed to the systematic regulation of NTFs and their receptors after EA.

Electro-acupuncture-induced neuroprotection is associated with activation of the IGF-1/PI3K/Akt pathway following adjacent dorsal root ganglionectomies in rats

“…Additional reports have shown that EA-induced increases in the expression of IGF-1 in the spared L6 DRG and associated dorsal horns may be associated with the intraspinal sprouting of DRG neurons in de-afferentated cats subjected to adjacent dorsal root ganglionectomies (26). Therefore, the enhanced CGRP- and GAP-43-IRs observed in the present study suggests that nerve regeneration, cone regrowth and synaptic formation were promoted in the de-afferentated spinal cord following EA treatment, and this may be used to reconstruct local circuitry for further functional recovery (9,45). The results of the present study also demonstrated that the overexpression of IGF-1 promoted EA-induced neuroplasticity and that IGF-1 siRNA treatment weakened this effect.…”

“…CGRP and GAP-43 serve key roles in regenerative neurite growth following spinal lesions (9). As a well-known marker for sensory axons transmitting pain sensations, the increased expression of CGRP is associated with nerve regeneration following lesion (44).…”

“…It is a major component of the motile ‘growth cones’ that form the tips of elongating axons. Increases in the number of GAP-43-IRs indicate the regrowth of cones and synaptic formation in the spinal cord following injury (9). EA has been demonstrated to promote the recovery of sensory or motor functions in patients with SCI (5) and increase neuroplasticity in de-afferentated spinal cords (6,7).…”

“…The L4 and L5 spinal cord segments of the rats were collected and post-fixed for 24 h using 4% paraformaldehyde (Sigma-Aldrich; Merck KGaA) at 4°C for IHC detection. The spinal cord tissue sections (20- µ m thickness) were processed as described previously (9,10). The sections were incubated with rabbit anti-rat polyclonal antibodies, calcitonin gene-related peptide (CGRP; cat.…”

“…Electro-acupuncture (EA), an effective acupuncture method, has been demonstrated to be a promising therapeutic method for functional recovery in patients with SCI (5). Previous studies have suggested that EA may promote functional repair (5-8) and enhance the intraspinal sprouting of spared afferents following SCI (9). Accumulating evidence suggested that alterations in the expression of neurotrophic factors (NTFs) may be associated with EA therapy-induced strengthening of spinal neuroplasticity following SCI (10,11).…”