Dorsal root ganglion neuroanatomy

The transmission of signals to the cell body from injured axons induces significant alterations in primary sensory neurons located in the ganglion tissue, the site of the perikaryon of the affected nerve fibers. Disruption of the continuity between the proximal and distal ends leads to substantial adaptability in ganglion cells and induces macrophage-like activity in the satellite cells. Research findings have demonstrated the plasticity of satellite cells following injury. Satellite cells work together with sensory neurons to extend the interconnected surface area in order to permit effective communication...

OBJECTIVE: To test the protective effects of Garcinia kola and curcumin on the ganglion tissues of diabetic rats following the use of autologous vein graft in peripheral nerve transection injury. METHODS: The sciatic nerve on the right side was transected, and anastomosis was performed between the proximal and distal ends using an autologous vein graft. Curcumin and Garcinia kola seed extract were administered daily by oral gavage. The ganglion tissues were harvested after a 90-day waiting period...

Neuropathic pain arises from damage or disorders affecting the somatosensory system. In rats, L5 nerve injury induces thermal and mechanical hypersensitivity/hyperalgesia. Recently, we demonstrated that applying resiniferatoxin (RTX) directly on uninjured L3 and L4 nerves alleviated thermal and mechanical hypersensitivity resulting from L5 nerve injury. Herein, using immunohistochemistry, Western blot, and qRT-PCR techniques, we reveal that perineural application of RTX (0.002%) on the L4 nerve substantially downregulated the expression of its receptor (Trpv1) and three different voltage-gated ion channels (Nav1...

INTRODUCTION: Recovery from peripheral nerve injuries is poor because axon regeneration is slow and inefficient. Experimental therapies that increase signaling of neuronal brain-derived neurotrophic factor (BDNF) through its TrkB receptor or through its downstream effectors enhance axon regeneration, increasing the number of motor and sensory neurons whose axons successfully regenerate and reinnervate muscle targets. The goal of this study was to compare the proportions of four different classes of sensory (dorsal root ganglion, DRG) neurons that successfully reinnervate two different muscle targets in control mice and mice treated pharmacologically to enhance axon regeneration...

The somatosensory neurons in the dorsal root ganglion (DRG) are responsible to detect peripheral physical and noxious stimuli, and then transmit these inputs into the central nervous system. DRG neurons are composed of various subpopulations, which are suggested to respond to different stimuli, such as mechanical, thermal, and cold perception. For a long time, DRG neurons were classified based on anatomical criteria. Recently, single-cell (scRNA-seq) and single-nucleus RNA-sequencing (snRNA-seq) has advanced our understanding of the composition and functional heterogeneity of both human and rodent DRG neurons at single-cell resolution...

AIMS: Transient receptor potential melastatin-7 (TRPM7) is a selective cation permeable channel which plays important roles in cellular and developmental biology such as cell proliferation, survival, differentiation and migration. This channel is also known to be necessary for transmitter release in the peripheral nervous system. In this study, immunohistochemistry for TRPM7 was conducted in the rat lumbar dorsal root ganglion (DRG). METHODS: Triple immunofluorescence methods were used to demonstrate distribution of TRPM7 and its relationship to other TRP channels in the DRG...

Endomorphin-2 (EM2)-immunoreactive (ir) fibers and terminals in the superficial laminae (lamina I and II) of the spinal dorsal horn (SDH) primarily come from neurons in the ipsilateral dorsal root ganglion (DRG), which are important for nociceptive information transmission and modulation. However, the morphological features of EM2-ir neurons and fibers in the DRG and terminals in the SDH under ultrastructural levels have not been completely revealed. The present study observed the distributions of EM2-ir neurons, fibers and terminals in the DRG and SDH and detected their ultrastructural features using immune-electron microscopy...

The purpose of this report is to describe the technical aspects of CT-guided C2 dorsal root ganglion diagnostic block and radiofrequency ablation for refractory cervicogenic headache. CT guidance allows precise and safe positioning of a needle adjacent to the C2 dorsal root ganglion. At-risk neural and vascular structures can be avoided with CT, and it can provide a thorough understanding of upper cervical neuroanatomy.

Tracing the evolution of the siboglinid group, peculiar group of marine gutless annelids, requires the detailed study of the fragmentarily explored central nervous system of vestimentiferans and other siboglinids. 3D reconstructions of the neuroanatomy of Riftia revealed that the "brain" of adult vestimentiferans is a fusion product of the supraesophageal and subesophageal ganglia. The supraesophageal ganglion-like area contains the following neural structures that are homologous to the annelid elements: the peripheral perikarya of the brain lobes, two main transverse commissures, mushroom-like structures, commissural cell cluster, and the circumesophageal connectives with two roots which give rise to the palp neurites...

The rabbit is widely used in experimental cardiac physiology, but the neuroanatomy of the rabbit heart remains insufficiently examined. This study aimed to ascertain the architecture of the intrinsic nerve plexus in the walls and septum of rabbit cardiac ventricles. In 51 rabbit hearts, a combined approach involving: (i) histochemical acetylcholinesterase staining of intrinsic neural structures in total cardiac ventricles; (ii) immunofluorescent labelling of intrinsic nerves, nerve fibres (NFs) and neuronal somata (NS); and (iii) transmission electron microscopy of intrinsic ventricular nerves and NFs was used...

The efficacy of anterograde labeling of the central projections of primary afferent fibers were compared between biotinylated dextran amine (BDA), neurobiotin (NB) and Phaseolus vulgaris-leucoagglutinin (PHA-L) after injections into the L5 or T13 dorsal root ganglia (DRGs) of adult rats. Excellent labeling was obtained with BDA, which visualized fibers with fine terminal boutons in the L5 and T13 spinal cord segments, Clarke's nucleus and the gracile nucleus. Rarely observed crossed projections to the gracile nucleus and L5 ventral horn of the contralateral side could also be distinguished...

While the crucial role of neurally produced nitric oxide in mediating penile erection is well established, the understanding of the peripheral neuroanatomy of the nitric oxide-ergic pathways is still incomplete. This study was designed to elucidate further the distribution of nitric oxide synthase, and its relation to the distribution of neuropeptides and tyrosine hydroxylase in all penis-projecting neural pathways. A triple-labelling technique was employed, with the retrograde tracer Fluoro Gold combined with neuropeptide immunohistochemistry and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry, a marker of nitric oxide synthase...

The internal organization of the third and fourth thoracic ganglia of the crayfish, Pacifastacus leniusculus, was studied in serial sections stained with osmium ethyl gallate. The aims were 1) to provide an anatomical framework for studies of sensorimotor integration in the walking system and 2) to explore possible homologies with abdominal ganglia in crayfish and with the thoracic ganglia of insects. Crayfish thoracic ganglia show several intersegmental homologies with the unfused ganglia of the abdominal nervous system: 1) Longitudinal tracts and dorsal commissures are arranged similarly, allowing use of the same nomenclature...

The neuroanatomy of a serotonin neurohemal system in the head of Periplaneta americana was studied by means of immunohistochemistry, cobalt backfilling, transmission electron microscopy, and nerve transection. This neurohemal system is supplied by bilateral groups of two or three neurons whose somata are located ventrally in the subesophageal ganglion, near the root of each mandibular nerve. Axons of these serotoninergic neurons extend into all of the nerves of the mouth parts but reach most of these nerves by a very circuitous route...

Effects of mild microwave treatment (1 hr, 37 degrees C) on the in vitro development of rat mechanically dissociated dorsal root ganglion (DRG) neurons were investigated to establish whether microwave irradiation effects exist on nervous tissue other than heat induced tissue fixation. Phase contrast microscopy and immunocytochemical neurofilament stainings did not reveal significant differences between irradiated (2 hr after isolation) and control cultures, maintained up till 21 days. The electrophysiological properties of microwave exposed and non-exposed DRG neurons were compared using the whole-cell patch-clamp technique...