Two pairs of wire electrodes were used to record afferent and efferent single fibre extracellular action potentials (APs) from human nerve root filaments. The nerve fibres were identified according to the group to which they belong by comparing the afferent and efferent conduction velocity distribution histograms and identifying peaks and ranges of nerve fibre groups. Secondary muscle spindle afferents and alpha 2-motoneurones (FR) were identified by having the same peak group conduction velocity (calibration relation), which is 50 m/s at 36 degrees C. On the basis of AP wave form comparisons, the natural impulse patterns of five secondary muscle spindle afferents, two fusimotor motoneurones and two oscillatory firing alpha 2-motoneurones could be identified in the dorsal S4 root. The patterns of single endings of secondary spindle afferent fibres could be identified. The shortest interspike intervals of single endings of all secondary muscle spindle afferents had the same duration as the shortest interspike intervals of the two fusimotor fibres (80 ms) and equalled a half of the oscillation period of one repetitively firing alpha 2-motoneurone (6 Hz) probably innervating the external anal sphincter (three AP impulse train firing). In another more rostral dorsal root filament (probably S3 or S2) of the same human, the interspike intervals of six secondary spindle afferents were more variable. The values of peaks in the interspike interval distributions ranged from 60 to 102 ms. In the coccygeal root, the interspike interval duration ranged from 160 to 185 ms, directly contributing to the drive of the oscillatory firing alpha 2-motoneurone. The different agreement between the oscillation period and the interspike intervals of the spindle afferents in different segments indicate that the oscillatory firing CNS circuitry was localized within S3 to S5 segments of the conus medullaris for the drive of the anal sphincter. An alpha 2-motoneurone firing repeatedly with 1 to 2 AP impulse trains, innervating most likely the external urethral sphincter, fired at a frequency of 9.1 to 6.7 Hz, a similar frequency of the oscillation as the interspike intervals from two activated stretch receptors of the urinary bladder wall. The measurements of this brain-dead human indicates that in this case the neuronal circuitry driving the external anal sphincter was mainly confined to the sacral micturition and defecation centre, mainly located in the S3 to S5 segments.
- MeSH
- akční potenciály fyziologie MeSH
- axony fyziologie MeSH
- elektrická stimulace MeSH
- lidé MeSH
- mícha cytologie fyziologie MeSH
- močový měchýř inervace fyziologie MeSH
- motorické neurony fyziologie MeSH
- nervosvalová vřeténka fyziologie MeSH
- nervové vedení fyziologie MeSH
- neurony aferentní fyziologie ultrastruktura MeSH
- neurony eferentní fyziologie ultrastruktura MeSH
- uretra inervace fyziologie MeSH
- urodynamika fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
In the present paper the ultrastructural similarities among the terminal portions of Pacinian corpuscles, the nodes of Ranvier, and the initial segments of primary sensory neurons are pointed out. Our conclusion is based on our observations of cat Pacinian corpuscles and other general knowledge of the node of Ranvier and the initial segment published elsewhere. The morpho-functional similarities of three principal excitable regions of the sensory nerve fibres (the initial segments, the node of Ranvier, and the terminal portions of sensory nerve formations) are illustrated by identical distribution of the enzymes which are associated with ionic transport (alkaline phosphatase, Mg(2+)-ATPase), and non-specific cholinesterase. Furthermore, the polyanionic material revealed by Alcian blue staining in three excitable sites of the sensory axon confirms the supposition that excitable axolemma cannot be considered in the isolation of its surroundings produced by Schwann cells.
- MeSH
- axony chemie ultrastruktura MeSH
- histocytochemie MeSH
- kočky MeSH
- krysa rodu Rattus MeSH
- myši MeSH
- neurony aferentní chemie ultrastruktura MeSH
- Ranvierovy zářezy chemie ultrastruktura MeSH
- Vater-Paciniho tělíska chemie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- krysa rodu Rattus MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The ultrastructure of peripheral sensory nerves was investigated in adult Wistar rats suffering from experimental diabetes mellitus 6 and 10 weeks after the injection of streptozotocin. Giant axons were seen in sections from the nerves of streptozotocin-treated rats; some contained masses of neurofilaments, others were predominantly filled with ill-defined vesicles. At the swollen axons, the myelin sheath was thinned or absent. In other regions, large intramyelinic vacuoles were observed. A number of nerve fibers broke down completely and underwent Wallerian degeneration. This was accompanied by Schwann cell proliferation and formation of Büngner bands. Concomitantly with axonal degeneration, nerve regeneration started from intact internodes. The pathomorphology of streptozotocin diabetic neuropathy closely resembles that of some toxic distal axonopathies. This points to a common metabolic basis of giant axonopathies of different etiology.
- MeSH
- axony ultrastruktura MeSH
- experimentální diabetes mellitus patologie MeSH
- intermediární filamenta ultrastruktura MeSH
- krysa rodu Rattus MeSH
- nervová vlákna ultrastruktura MeSH
- neurony aferentní ultrastruktura MeSH
- periferní nervy patologie MeSH
- potkani Wistar MeSH
- regenerace nervu MeSH
- Schwannovy buňky ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Crystalloid tubular arrays in the cytoplasm of canine sensory neurons were found after repeated 40 min aortic occlusion. The inclusions were composed of 35-40 nm tubules in parallel rows connected by fine side-arms. The tubular aggregates seem to be transient formations and were observed mostly in animals with 2-3 days of survival. After longer survival period (6 days) when signs of recovery in neurons were noticed, the crystalloids were not found.
- MeSH
- adenosintrifosfát metabolismus MeSH
- cytoplazma ultrastruktura MeSH
- elektronová mikroskopie MeSH
- ischemie patologie MeSH
- mícha krevní zásobení patologie ultrastruktura MeSH
- neurony aferentní patologie ultrastruktura MeSH
- psi MeSH
- spinální ganglia krevní zásobení patologie ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- psi MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- adenosintrifosfát MeSH
Non-specific cholinesterase (ChE) activity was studied histochemically at light and electron microscopical levels in dorsal root ganglia (DRG) of adult mice. The reaction staining and diameter of neuron cells perykaria were measured by using an image analysis system. The methodological approach enable to distinguish 8 subclasses of primary sensory neurons. The proportion of individual subclasses was mapping in three subsequent cervical, thoracal and lumbar DRG. The populations of small-sized neurons increased towards lumbar level similarly as medium and small neurons exhibiting high ChE reactivity. The variations in ChE-containing neurons among DRG from different area may reflect differences in modality-specific primary sensory neurons at each spinal cord level. In addition, the effect of 3 week sciatic nerve transection on the percentage of the subclasses in L4-L6 DRG has been investigated. The number of large neurons was reduced and a decrease of ChE reactivity in medium-size neurons was found in DRG on the operated side. Thus, the present results demonstrate a selective affectation of primary sensory neurons in mouse DRG by the peripheral nerve transection. Different amounts of the reaction product corresponding with ChE activity were found in the nuclear envelope and the cisternae of rough endoplasmic reticulum.
- MeSH
- cholinesterasy metabolismus MeSH
- elektronová mikroskopie MeSH
- histocytochemie MeSH
- myši MeSH
- neurony aferentní enzymologie ultrastruktura MeSH
- spinální ganglia cytologie enzymologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- cholinesterasy MeSH
- MeSH
- neurony aferentní cytologie ultrastruktura MeSH
- obratlovci MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- kočky MeSH
- lidé MeSH
- Macaca MeSH
- nervová vlákna ultrastruktura MeSH
- nervová zakončení ultrastruktura MeSH
- neurony aferentní ultrastruktura MeSH
- zvířata MeSH
- Check Tag
- kočky MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
