Comprehensive assessment of peripheral innervation and microcirculatory function in local cold trauma

Актуальность криопоражений обусловлена большим числом пострадавших, сложностью лечения, длительной утратой трудоспособности, тяжелыми последствиями и, как следствие, высоким уровнем инвалидизации. Цель исследования -- оценка изменений микрокровотока и периферической иннервации при местной холодовой травме и формирование прогностической модели уровня повреждения конечности. Методика. Под наблюдением было 35 больных с местной холодовой травмой нижних конечностей III-IV степени. Использован неинвазивный метод лазерной доплеровской флуометрии с помощью аппарата ЛАКК-02, а также метод накожной электронейромиографии с помощью аппарата Нейро-ВМП, компании Нейрософт. Результаты. Несмотря на гипотетически функциональную связь между микрокровотоком кожи и уровнем отморожения пораженной конечности, статистически значимых результатов получено не было (p > 0,05), что свидетельствует о более сложном генезе патологических изменений в пораженной конечности. Между тем, у пострадавших с местной криотравмой отмечены выраженные изменения периферической иннервации. Нейропатия прогрессирует с увеличением уровня повреждения. Заключение. У пациентов с местной холодовой травмой отмечается снижение биоэлектрической активности мышц в области пораженной конечности. Cryotrauma is relevant due to a large number of patients, the complexity of treatment, the likelihood of severe complications, and long-term disability. The aim was to assess oscillations in microcirculation and peripheral innervation during regional cold injury, and to form a prognostic model according to the severity of limb injury. Methods. Studies were carried out in 35 patients with III-IV degree local cold injury of a leg. Non-invasive laser Doppler flowmetry was performed with a LAKK-02 device, and peripheral innervation was evaluated by cutaneous electroneuromyography with a Neurosoft Neuro-VMP device. The patients were divided into 3 groups depending on the injury. Results. Despite the hypothetical, functional relationship between skin microcirculatory blood flow and the degree of frostbite of the affected tissue, no statistically significant association was detected (p > 0.05), which indicates a more complex genesis of the cold-induced pathology. However, there were pronounced changes in neural activity in this tissue. Neuropathy increased with increasing injury. Conclusions. In patients with local cold trauma there is a decrease in the bioelectric activity of the muscles in the damaged tissue.

On the question of the peripheral innervation of the rectum. Critical and experimental research

All experiments were made by you 56. Of these, 10 experiments with negative pressure, 8 experiments with double registration (according to Courtade and Guyon` y), 15 with simultaneous registration of three bowel sections (colonis, recti and sphinct. Inter.), 4 experiments with irritation spinal roots, 2 experiments for examining the external sphincter. The remaining 17 embrace the usual experiments of investigating the movements of the recti under the influence of the irritated intestinal nerves according to the method indicated by us in the beginning of our work; this also included 5 experiments with combined irritations n. erigentis and n. hypogastrici.

The neuropathic phenotype of the K/BxN transgenic mouse with spontaneous arthritis: pain, nerve sprouting and joint remodeling

The adult K/BxN transgenic mouse develops spontaneous autoimmune arthritis with joint remodeling and profound bone loss. We report that both males and females display a severe sustained tactile allodynia which is reduced by gabapentin but not the potent cyclooxygenase inhibitor ketorolac. In dorsal horn, males and females show increased GFAP+ astrocytic cells; however, only males demonstrate an increase in Iba1+ microglia. In dorsal root ganglia (DRG), there is an increase in CGRP+, TH+, and Iba1+ (macrophage) labeling, but no increase in ATF3+ cells. At the ankle there is increased CGRP+, TH+, and GAP-43+ fiber synovial innervation. Thus, based on the changes in dorsal horn, DRG and peripheral innervation, we suggest that the adult K/BxN transgenic arthritic mice display a neuropathic phenotype, an assertion consistent with the analgesic pharmacology seen in this animal. These results indicate the relevance of this model to our understanding of the nociceptive processing which underlies the chronic pain state that evolves secondary to persistent joint inflammation.

Abnormal Reinnervation of Denervated Areas Following Nerve Injury Facilitates Neuropathic Pain

An injury to peripheral nerves leads to skin denervation, which often is followed by increased pain sensitivity of the denervated areas and the development of neuropathic pain. Changes in innervation patterns during the reinnervation process of the denervated skin could contribute to the development of neuropathic pain. Here, we examined the changes in the innervation pattern during reinnervation and correlated them with the symptoms of neuropathic pain. Using a multispectral labeling technique—PainBow, which we developed, we characterized dorsal root ganglion (DRG) neurons innervating distinct areas of the rats’ paw. We then used spared nerve injury, causing partial denervation of the paw, and examined the changes in innervation patterns of the denervated areas during the development of allodynia and hyperalgesia. We found that, differently from normal conditions, during the development of neuropathic pain, these areas were mainly innervated by large, non-nociceptive neurons. Moreover, we found that the development of neuropathic pain is correlated with an overall decrease in the number of DRG neurons innervating these areas. Importantly, treatment with ouabain facilitated reinnervation and alleviated neuropathic pain. Our results suggest that local changes in peripheral innervation following denervation contribute to neuropathic pain development. The reversal of these changes decreases neuropathic pain.

Neural crest-derived neurons invade the ovary but not the testis during mouse gonad development

Testes and ovaries undergo sex-specific morphogenetic changes and adopt strikingly different morphologies, despite the fact that both arise from a common precursor, the bipotential gonad. Previous studies showed that recruitment of vasculature is critical for testis patterning. However, vasculature is not recruited into the early ovary. Peripheral innervation is involved in patterning development of many organs but has been given little attention in gonad development. In this study, we show that while innervation in the male reproductive complex is restricted to the epididymis and vas deferens and never invades the interior of the testis, neural crest-derived innervation invades the interior of the ovary around E16.5. Individual neural crest cells colonize the ovary, differentiate into neurons and glia, and form a dense neural network within the ovarian medulla. Using a sex-reversing mutant mouse line, we show that innervation is specific to ovary development, is not dependent on the genetic sex of gonadal or neural crest cells, and may be blocked by repressive guidance signals elevated in the male pathway. This study reveals another aspect of sexually dimorphic gonad development, establishes a precise timeline and structure of ovarian innervation, and raises many questions for future research.

Central and peripheral innervation patterns of defined axial motor units in larval zebrafish

Spinal motor neurons and the peripheral muscle fibers they innervate form discrete motor units that execute movements of varying force and speed. Subsets of spinal motor neurons also exhibit axon collaterals that influence motor output centrally. Here, we have used in vivo imaging to anatomically characterize the central and peripheral innervation patterns of axial motor units in larval zebrafish. Using early born ‘primary’ motor neurons and their division of epaxial and hypaxial muscle into four distinct quadrants as a reference, we define three distinct types of later born ‘secondary’ motor units. The largest are ‘m-type’ units, which innervate deeper fast-twitch muscle fibers via medial nerves. Next in size are ‘ms-type’ secondaries, which innervate superficial fast-twitch and slow fibers via medial and septal nerves, followed by ‘s-type’ units, which exclusively innervate superficial slow muscle fibers via septal nerves. All types of secondaries innervate up to four axial quadrants. Central axon collaterals are found in subsets of primaries based on soma position and predominantly in secondary fast-twitch units (m, ms) with increasing likelihood based on number of quadrants innervated. Collaterals are labeled by synaptophysin-tagged fluorescent proteins, but not PSD95, consistent with their output function. Also, PSD95 dendrite labeling reveals that larger motor units receive more excitatory synaptic input. Collaterals are largely restricted to the neuropil, however perisomatic connections are observed between motor units. These observations suggest that recurrent interactions are dominated by motor neurons recruited during stronger movements and set the stage for functional investigations of recurrent motor circuitry in larval zebrafish.