Effective treatments for neuropathic pain are lacking due to our limited understanding of the mechanisms. The circRNAs are mainly enriched in the central nervous system. However, their function in various physiological and pathological conditions have yet to be determined. Here, we identified circFhit, an exon-intron circRNA expressed in GABAergic neurons, which reduced the inhibitory synaptic transmission in the spinal dorsal horn to mediate spared nerve injury-induced neuropathic pain. Moreover, we found that circFhit decreased the expression of GAD65 and induced hyperexcitation in NK1R⁺ neurons by promoting the expression of its parental gene Fhit in cis. Mechanistically, circFhit was directly bound to the intronic region of Fhit, and formed a circFhit/HNRNPK complex to promote Pol II phosphorylation and H2B monoubiquitination by recruiting CDK9 and RNF40 to the Fhit intron. In summary, we revealed that the exon-intron circFhit contributes to GABAergic neuron-mediated NK1R⁺ neuronal hyperexcitation and neuropathic pain via regulating Fhit in cis.
Rats ; Animals ; Posterior Horn Cells/pathology* ; Spinal Cord Dorsal Horn/metabolism* ; Neuralgia ; Synaptic Transmission

Electrodiagnostic studies were carried out in 31 patients with neurological complications of AHC, who were seen at Seoul National University Hospital from August 1981 to February 1982. Age of the patients ranged from 14 to 62 years. Both velocity and distal latency of motor and sensory conduction were normal in the nerves innervating the affected muscles. During the acute phase of motor paralysis, there was an absence of electrical activity in completely paralysed muscles. In partially denervated muscles, there were polyphasic motor unit potentials of normal duration and amplitrde on weak contraction and reduced interference on maximal effort. From the third or fourth week onwards, fibrillation potentials and positive sharp waves at rest were observed in paraspinal muscles in most cases. All the above findings were supporting the view that the principal site of involvement for the paralytic phenomena is at the level of the anterior horn cells or anterior roots.
Anterior Horn Cells ; Conjunctivitis, Acute Hemorrhagic* ; Humans ; Muscles ; Paralysis ; Paraspinal Muscles ; Seoul

OBJECTIVETo examine the effect of acute incisional pain on the expression of connexin 43 in rat spinal cord dorsal horn.

METHODSEighty rats were assigned into control group without any treatment and incisional pain group with incision surgery. For paw incisions, a 1-cm longitudinal incision was made through the skin and fascia of the plantar aspect of the right hind paw. After surgery, the 50% paw withdrawal threshold (PWT) was assessed in response to a tactile stimulus with calibrated von Frey monofilaments at 1, 2, 4 and 24 h, respectively. The spinal cord dorsal horn of rats was isolated at 1, 2, and 4 h after the surgery to assess the expression of connexin 43 using Western blotting and immunofluorescence assay.

RESULTSThe 50% PWT of the rats was significantly decreased after the incision surgery, and this decrement was the most obvious at 2 and 4 h. Western blotting and immunofluorescence assay showed that the expression of connexin 43 in the spinal cord dorsal horn was significantly increased in rats receiving the surgery especially at 2 and 4 h after the surgery.

CONCLUSIONIncision surgery induces an significant increase in connexin 43 expression in rat spinal cord dorsal horn, suggestting an potential role of connexin43 in postoperative incisional pain.

OBJECTIVETo study on mechanisms of acupuncture in relieving visceral pain.

METHODSIn SD rats CRD was used as noxious visceral stimuli. Activities of spinal dorsal horn wide dynamic (WDR) neurons of L1-L13 were recorded by extracellular microelectrode technique. Acupuncture was given at ipsi-lateral and contra-lateral Zusanli (ST 36) of the same segmental innervation of rectum and colon.

RESULTSVisceral noxious afferent could significantly activate spinal dorsal horn convergent neurons, and mechanical stimulation of contra-lateral body surface and hand acupuncture at Zusanli (ST 36) could inhibit this noxious response. When the spinal cord was acutely blocked, the inhibiting CRD effect of needling CRD effect of needling contra-lateral Zusanli (ST 36) completely disappeared.

CONCLUSIONAcupuncture and visceral noxious afferent signals converge and interact each other in spinal level, and acupuncture at acupoint can inhibit the spinal dorsal horn neuron respon se activated by visceral noxious afferent and this action needs the participation of the center above the spinal cord.

We analyzed aquaporin (AQP) expression in the rat spinal cord following an electrical shock (ES) to elucidate the roles of AQP in spinal cord injury (SCI) induced by an electrical burn. In control animals, AQP1 immunoreactivity was observed in the small diameter dorsal horn fibers of laminae I and II and in astrocytes and neurons in the spinal cord. Both AQP4 and AQP9 immunoreactivity were detected in astrocytes. One week after the ES, AQP1 immunoreactivity in dorsal horn fibers was downregulated to 83, 61, and 33% of control levels following a 1-, 4-, or 6-second ES, respectively. However, AQP1 immunoreactivity in ventral horn neurons increased to 1.3-, 1.5-, and 2.4-fold of control levels following a 1-, 4-, or 6-second ES, respectively. AQP4 immunoreactivity was upregulated after an ES in laminae I and II astrocytes in a stimulus-intensity independent manner. Unlike AQP1 and AQP4, AQP9 immunoreactivity was unaffected by the ES. These findings indicate that altered AQP immunoreactivity may be involved in SCI following an ES.
Animals ; Anterior Horn Cells ; Aquaporins ; Astrocytes ; Burns ; Horns ; Neurons ; Rats ; Shock ; Spinal Cord ; Spinal Cord Injuries

The present study was undertaken to confirm whether melittin, a major constituent of whole bee venom (WBV), had the ability to produce the same nociceptive responses as those induced by WBV. In the behavioral experiment, changes in mechanical threshold, flinching behaviors and paw thickness (edema) were measured after intraplantar (i.pl.) injection of WBV (0.1 mg & 0.3 mg/paw) and melittin (0.05 mg & 0.15 mg/paw), and intrathecal (i.t.) injection of melittin (6microgram). Also studied were the effects of i.p. (2 mg & 4 mg/kg), i.t. (0.2microgram & 0.4microgram) or i.pl. (0.3 mg) administration of morphine on melittin- induced pain responses. I.pl. injection of melittin at half the dosage of WBV strongly reduced mechanical threshold, and increased flinchings and paw thickness to a similar extent as those induced by WBV. Melittin- and WBV-induced flinchings and changes in mechanical threshold were dose- dependent and had a rapid onset. Paw thickness increased maximally about 1 hr after melittin and WBV treatment. Time-courses of nociceptive responses induced by melittin and WBV were very similar. Melittin-induced decreases in mechanical threshold and flinchings were suppressed by i.p., i.t. or i.pl. injection of morphine. I.t. administration of melittin (6microgram) reduced mechanical threshold of peripheral receptive field and induced flinching behaviors, but did not cause any increase in paw thickness. In the electrophysiological study, i.pl. injection of melittin increased discharge rates of dorsal horn neurons only with C fiber inputs from the peripheral receptive field, which were almost completely blocked by topical application of lidocaine to the sciatic nerve. These findings suggest that pain behaviors induced by WBV are mediated by melittin-induced activation of C afferent fiber, that the melittin- induced pain model is a very useful model for the study of pain, and that melittin-induced nociceptive responses are sensitive to the widely used analgesics, morphine.
Analgesics ; Bee Venoms* ; Bees* ; Lidocaine ; Melitten* ; Morphine ; Nerve Fibers, Unmyelinated ; Nociception ; Posterior Horn Cells ; Sciatic Nerve

The changes of anterior horn cell excitability and conduction of the nervous system by the electrical stimulation of nerve have been reported in both vivo and vitro studies. Purpose of this study is to observe the neurophysiologic changes of nerves by 10 Hz electrical stimulation on polyneuropathic peripheral nerves. Subjects were 18 diabetic polyneuropathic patients diagnosed by the conduction studies. Electrophysiologic studies were performed in both right and left tibial nerves before and after conditioning of the right tibial nerve. Electrophysiologic studies included five tests which were the sural sensory and tibial motor conduction(abductor hallucis), F response(abductor hallucis), H reflex(gastrosoleus) and somatosensory evoked potential(ankle, SEP). Ten Hz rectangular electrical current was used for the conditioning stimulation. It was applied to the popliteal tibial nerve with the tolerable maximal intensity(10-24 mA) for 5 minutes. Following changes were statistically significant in statistics after the conditioning. Prolongation of F latency (p<0.05), increases of F chronodispersion, duration and area(p<0.05), prolongation of H latency(p<0.05), increase of H amplitude(p<0.05), decrease of P1 latency of SEP(p<0.01) and increase of P1N1 amplitude of SEP(p<0.01) were seen in both conditioned and unconditioned legs. Increase of F wave conduction time(FWCT) and decrease of F wave conduction velocity (FWCV) were seen in conditioned leg(p<0.05). Above findings suggest that certain electrical stimulation of polyneuropathic nerve may cause increase of the anterior horn cell excitability, fascilitation of the SEP conduction and slowness of alpha motor conduction to and from the spinal cord.
Anterior Horn Cells ; Electric Stimulation ; Humans ; Leg ; Nervous System ; Peripheral Nerves ; Spinal Cord ; Tibial Nerve*

The association between pediatric Chiari malformation and the development of syringomyelia has been well documented. Scoliosis in the patient with syringomyelia is thought to be secondary to anterior horn cell damage, which innervate the muscles of trunk, by an asymmetrically expanded syrinx. In pediatric patients, the neurologic signs and symptoms due to Chiari malformation and syringomyelia show much lower frequency but the incidence of scoliosis is very high. Thus, the MRI study for the diagnosis of the underlying syringomyelia and Chiari malfornation is essential in pediatric scoliosis patients, which may otherwise be misdiagnosed for idiopathic scoliosis. We present a case of Chiari type I malformation associated with syringomyelia and scoliosis.
Anterior Horn Cells ; Child* ; Diagnosis ; Humans ; Incidence ; Magnetic Resonance Imaging ; Muscles ; Neurologic Manifestations ; Scoliosis* ; Syringomyelia*

Mullerian abnormalities serve as a fascinating framework with which to understand both the embryonic development and normal reproductive functioning. Uterine malformations are closely related to an abnormal uterine cavity, which is thought to impair the reproductive performance of patients. Pregnancy in a non- communicating rudimentary horn is extremely rare and, it is a life threatening condition because most cases terminate by uterine rupture by the second trimester. A case of such uterine anomaly, complicated by placenta accreta and ipsilateral renal agenesis in an 18-year-old primigravid is presented. Exploratory laparotomy with excision of left rudimentary horn uterus was performed. The hemorrhagic risk due to placenta accreta and that of spontaneous uterine rupture represent ample argument to recommend the immediate surgical removal of a pregnant rudimentary horn as soon as identification is carried out.
MULLERIAN ; DUCT ; PLACENTA ; ACCRETA ; RUDIMENTARY ; HORN ; UNICORNUATE ; UTERUS ; TRANSPERITONEAL ; SPERM MIGRATION ; ;

Dopamine has been generally known to exert antinociceptive action in behavioral pain test, such as tail flick and hot plate test, but there appears to be a great variance in the reports on the antinociceptive effect of dopamine depending on the dosage and route of drug administration and type of animal preparation. In the present study, the effects of dopamine on the responses of wide dynamic range (WDR) cells to mechanical, thermal and graded electrical stimuli were investigated, and the dopamine-induced changes in WDR cell responses were compared between animals with an intact spinal cord and the spinal animals. Spinal application of dopamine (1.3 & 2.6 mM) produced a dose-dependent inhibiton of WDR cell responses to afferent inputs, the pinch-induced or the C-fiber evoked responses being more strongly depressed than the brush-induced or the A-fiber evoked responses. The dopamine-induced inhibition was more pronounced in the spinal cat than in the cat with intact spinal cord. The responses of WDR cell to thermal stimulation were also strongly inhibited. Dopamine D2 receptor antagonist, sulpiride, but not D1 receptor antagonist, significantly blocked the inhibitory action of dopamine on the C-fiber and thermal responses of dorsal horn cells. These findings suggest that dopamine strongly suppresses the responses of WDR cells to afferent signals mainly through spinal dopamine D2 receptors and that spinal dopaminergic processes are under the tonic inhibitory action of the descending supraspinal pathways.
Animals ; Cats* ; Dopamine ; Posterior Horn Cells* ; Receptors, Dopamine D2 ; Spinal Cord ; Sulpiride