Postnatal changes in motoneurone electrotonic coupling studied in the in vitro rat lumbar spinal cord.

In vitro studies have repeatedly demonstrated that the neurotransmitters γ-aminobutyric acid (GABA) and glycine depolarize immature neurons in many areas of the CNS, including the spinal cord. This widely accepted phenomenon was recently challenged by experiments showing that the depolarizing action of GABA on neonatal hippocampus and neocortex in vitro was prevented by adding energy substrates (ES), such as the ketone body metabolite dl-β-hydroxybutyric acid (DL-BHB), lactate, or pyruvate to the artificial cerebrospinal fluid (ACSF). It was suggested that GABA-induced depolarizations in vitro might be an artifact due to inadequate energy supply when glucose is the sole energy source, consistent with the energy metabolism of neonatal rat brain being largely dependent on ESs other than glucose. Here we examined the effects of these ESs (DL-BHB, lactate, pyruvate) on inhibitory postsynaptic potentials (IPSPs) recorded from neonatal rat lumbar spinal cord motoneurons (MNs), in vitro. We report that supplementing the ACSF with physiologic concentrations of DL-BHB, lactate, or pyruvate does not alter the reversal potential of IPSPs ( EIPSP). Only high concentrations of pyruvate hyperpolarized EIPSP. In addition, the depolarizing action of GABA on primary afferent terminals was not affected by supplementing the ACSF with ES at physiologic concentrations. We conclude that depolarizing IPSPs in immature MNs and the primary afferent depolarizations are not caused by inadequate energy supply. Glucose at its standard concentration appears to be an adequate ES for the neonatal spinal cord in vitro.

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Berberine alleviates visceral hypersensitivity in rats by altering gut microbiome and suppressing spinal microglial activation

Acta Pharmacologica Sinica ◽

10.1038/s41401-020-00601-4 ◽

2021 ◽

Author(s):

Jin-dong Zhang ◽

Jiao Liu ◽

Shi-wei Zhu ◽

Yuan Fang ◽

Ben Wang ◽

...

Keyword(s):

Spinal Cord ◽

Gut Microbiome ◽

Microglial Activation ◽

Fecal Microbiota Transplantation ◽

Fecal Microbiota ◽

Visceral Hypersensitivity ◽

Lumbar Spinal Cord ◽

Microbial Composition ◽

Lumbar Spinal

AbstractAccumulating evidence shows that agents targeting gut dysbiosis are effective for improving symptoms of irritable bowel syndrome (IBS). However, the potential mechanisms remain unclear. In this study we investigated the effects of berberine on the microbiota-gut-brain axis in two rat models of visceral hypersensitivity, i.e., specific pathogen-free SD rats subjected to chronic water avoidance stress (WAS) and treated with berberine (200 mg· kg−1 ·d−1, ig, for 10 days) as well as germ-free (GF) rats subjected to fecal microbiota transplantation (FMT) from a patient with IBS (designated IBS-FMT) and treated with berberine (200 mg· kg−1 ·d−1, ig, for 2 weeks). Before the rats were sacrificed, visceral sensation and depressive behaviors were evaluated. Then colonic tryptase was measured and microglial activation in the dorsal lumbar spinal cord was assessed. The fecal microbiota was profiled using 16S rRNA sequencing, and short chain fatty acids (SCFAs) were measured. We showed that berberine treatment significantly alleviated chronic WAS-induced visceral hypersensitivity and activation of colonic mast cells and microglia in the dorsal lumbar spinal cord. Transfer of fecal samples from berberine-treated stressed donors to GF rats protected against acute WAS. FMT from a patient with IBS induced visceral hypersensitivity and pro-inflammatory phenotype in microglia, while berberine treatment reversed the microglial activation and altered microbial composition and function and SCFA profiles in stools of IBS-FMT rats. We demonstrated that berberine did not directly influence LPS-induced microglial activation in vitro. In both models, several SCFA-producing genera were enriched by berberine treatment, and positively correlated to the morphological parameters of microglia. In conclusion, activation of microglia in the dorsal lumbar spinal cord was involved in the pathogenesis of IBS caused by dysregulation of the microbiota–gut–brain axis, and the berberine-altered gut microbiome mediated the modulatory effects of the agent on microglial activation and visceral hypersensitivity, providing a potential option for the treatment of IBS.

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Vasoactive intestinal polypeptide produces depolarization and facilitation of C-fibre evoked synaptic responses in superficial dorsal horn neurones (laminae I–IV) of the rat lumbar spinal cord in vitro

Neuroscience Letters ◽

10.1016/s0304-3940(99)00794-6 ◽

1999 ◽

Vol 276 (1) ◽

pp. 1-4 ◽

Cited By ~ 7

Author(s):

X.H Liu ◽

R Morris

Keyword(s):

Spinal Cord ◽

Dorsal Horn ◽

Vasoactive Intestinal Polypeptide ◽

Lumbar Spinal Cord ◽

Superficial Dorsal Horn ◽

C Fibre ◽

Dorsal Horn Neurones ◽

Lumbar Spinal ◽

Synaptic Responses

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Long-duration perforated patch recordings from spinal interneurons of adult mice

Journal of Neurophysiology ◽

10.1152/jn.00673.2011 ◽

2011 ◽

Vol 106 (5) ◽

pp. 2783-2789 ◽

Cited By ~ 16

Author(s):

Andreas Husch ◽

Nathan Cramer ◽

Ronald M. Harris-Warrick

Keyword(s):

Spinal Cord ◽

Drug Application ◽

Lumbar Spinal Cord ◽

Spinal Cord Neurons ◽

Perforated Patch ◽

Adult Mice ◽

Vital Functions ◽

Cord Injury ◽

Lumbar Spinal

It has been very difficult to record from interneurons in acute slices of the lumbar spinal cord from mice >3 wk of age. The low success rate and short recording times limit in vitro experimentation on mouse spinal networks to neonatal and early postnatal periods when locomotor networks are still developmentally immature. To overcome this limitation and enable investigation of mature locomotor network neurons, we have established a reliable procedure to record from spinal cord neurons in slices from adult, behaviorally mature mice of any age. Two key changes to the established neonate procedure were implemented. First, we remove the cord by a dorsal laminectomy from a deeply anesthetized animal. This enables respiration and other vital functions to continue up to the moment the maximally oxygenated lumbar spinal cord is removed, improving the health of the slices. Second, since adult spinal cord interneurons appear more sensitive to the intracellular dialysis that occurs during whole cell recordings, we introduced perforated patch recordings to the procedure. Stable recordings up to 12 h in duration were obtained with our new method. This will allow investigation of changes in mature neuronal properties in disease states or after spinal cord injury and allow prolonged recordings of responses to drug application that were previously impossible.

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Development of locomotor activity induced by NMDA receptor activation in the lumbar spinal cord of the rat fetus studied in vitro

Developmental Brain Research ◽

10.1016/s0165-3806(96)00139-3 ◽

1996 ◽

Vol 97 (1) ◽

pp. 118-125 ◽

Cited By ~ 35

Author(s):

Shigeru Ozaki ◽

Toshiya Yamada ◽

Makito Iizuka ◽

Hiroshi Nishimaru ◽

Norio Kudo

Keyword(s):

Spinal Cord ◽

Locomotor Activity ◽

Nmda Receptor ◽

Receptor Activation ◽

Lumbar Spinal Cord ◽

Rat Fetus ◽

Lumbar Spinal ◽

Nmda Receptor Activation

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Development of the spatial pattern of 5-HT-induced locomotor rhythm in the lumbar spinal cord of rat fetuses in vitro

Neuroscience Research ◽

10.1016/s0168-0102(98)00029-7 ◽

1998 ◽

Vol 31 (2) ◽

pp. 107-111 ◽

Cited By ~ 29

Author(s):

Makito Iizuka ◽

Hiroshi Nishimaru ◽

Norio Kudo

Keyword(s):

Spinal Cord ◽

Spatial Pattern ◽

Lumbar Spinal Cord ◽

Locomotor Rhythm ◽

Rat Fetuses ◽

Lumbar Spinal

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Lipomeningocele associated with diplomyelia in a dog

Tierärztliche Praxis Ausgabe K Kleintiere / Heimtiere ◽

10.15654/tpk-170751 ◽

2018 ◽

Vol 46 (05) ◽

pp. 323-329 ◽

Cited By ~ 2

Author(s):

Nele Ondreka ◽

Sara Malberg ◽

Emma Laws ◽

Martin Schmidt ◽

Sabine Schulze

Keyword(s):

Spinal Cord ◽

Neurological Status ◽

Split Cord Malformation ◽

Lumbar Spinal Cord ◽

Histopathological Diagnosis ◽

Type I ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Subcutaneous Mass ◽

Lumbar Spinal

SummaryA 2-year-old male neutered mixed breed dog with a body weight of 30 kg was presented for evaluation of a soft subcutaneous mass on the dorsal midline at the level of the caudal thoracic spine. A further clinical sign was intermittent pain on palpation of the area of the subcutaneous mass. The owner also described a prolonged phase of urination with repeated interruption and re-initiation of voiding. The findings of the neurological examination were consistent with a lesion localization between the 3rd thoracic and 3rd lumbar spinal cord segments. Magnetic resonance imaging revealed a spina bifida with a lipomeningocele and diplomyelia (split cord malformation type I) at the level of thoracic vertebra 11 and 12 and secondary syringomyelia above the aforementioned defects in the caudal thoracic spinal cord. Surgical resection of the lipomeningocele via a hemilaminectomy was performed. After initial deterioration of the neurological status postsurgery with paraplegia and absent deep pain sensation the dog improved within 2 weeks to non-ambulatory paraparesis with voluntary urination. Six weeks postoperatively the dog was ambulatory, according to the owner. Two years after surgery the owner recorded that the dog showed a normal gait, a normal urination and no pain. Histopathological diagnosis of the biopsied material revealed a lipomeningocele which confirmed the radiological diagnosis.

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