Effect of electric stimulation of auricular acupuncture points on H-reflex

The non-nociceptive H-reflex in the musculus soleus were recorded before and after auricular electroacupuncture (AEAP) in patients with vertebrogenic pain syndrome. Changes of the H-reflex on the side of the pain syndrome were observed after ipsi- and contralateral AEAP, the latter producing effect more often. Changes of H-reflex are mainly of facilitating character (71.4%) and, rarely, of inhibitory character (14.3%). In the part of patients AEAP produced distinct facilitation of M-response.     

Bilateral changes in glutamate uptake,muscarinic receptor binding and acetylcholinesterase level in the rat hippocampus after unilateral entorhinal cortex lesions

This report examines the effects of unilateral electrolytic and knife-cut lesions of entorhinal cortex on glutamate uptake, the muscarinic receptor [³H]QNB binding and acetylcholinesterase (AChE) activity in the dorsal and ventral parts of the ipsi- and contralateral hippocampus of the rat.We found that (1) in unoperated, control rats there are no pre-existing differences in the level of the investigated markers between the right and left hippocampus, (2) both electrolytic and knife-cut lesions of the entorhinal cortex evoke bilateral changes in the investigated markers and (3) the character of the response is dependent on the survival time and on the hippocampal part involved. Four days after operation a substantial reduction in glutamate uptake was found in both the dorsal and ventral parts of the ipsi- and contralateral hippocampus. At the same time there was a drop in muscarinic receptor binding, while AChE activity was not affected. The decrease in glutamate uptake persisted on the 21st postoperative day, whereas muscarinic receptor binding was enhanced, in comparison with the control level, in the ventral part of both the ipsi- and contralateral hippocampus. This overshoot was not so evident on the 30th postoperative day; glutamate uptake at that time reached or even surpassed the control level. Enhancement of AChE activity on the ipsi- and contralateral sides was noted on both the 21st and 30th day after operation.We suggest the following interpretation of these results: (1) glutamatergic projections from the entorhinal cortex to the hippocampus are bilateral, (2) some transneuronal changes probably contribute to the decline in glutamate uptake, particularly on the contralateral side, (3) neuronal depolarization does not seem to be the only mechanism responsible for the decrease in muscarinic receptor binding and (4) some compensatory mechanisms occur in the hippocampus at a later time after the lesion.Moreover, we believe that the use of the contralateral side as a control should be considered with caution in studies with unilaterally lesioned animals.     

Striatal dopamine levels after unilateral lesions of the substantia nigra: evidence for a contralateral decrease

Unilateral electrolytical and chemical (6-hydroxydopamine) lesions in the substantia nigra (SN) of rats were followed 7 days later by considerable bilateral decreases of neostriatal dopamine (DA) levels. Similarly, the DA content of the substantia nigra decreased not only ipsilaterally but contralaterally as well. Positive correlations were found between ipsi- and contralateral nigral DA levels, ipsi- and contralateral striatal DA and between the DA level of the SN and the striatum of the corresponding side both ipsi- and contralaterally to the lesion.     

Different fusimotor reflexes from the ipsi- and contralateral hind limbs of the cat assessed in the same primary muscle spindle afferents

Experiments were performed in forty-five cats anaesthetized with alpha-chloralose. The aim of the study was to investigate a sample of primary muscle spindle afferents from triceps muscle with respect to their fusimotor reflex control from ipsi- as well as contralateral hind limb. Primary muscle spindle afferents of the triceps surae muscle were recorded from the mean rate of firing and the modulation of the afferent response to sinusoidal stretching of the triceps surae muscle was determined. Test measurements were made during tonic stretch of the ipsilateral PBSt, contralateral PBSt, contralateral triceps muscle or during extension of the intact contralateral hind limb. Control measurements were made with ipsi- and contralateral PBSt as well as contralateral triceps muscles relaxed and with contralateral hind limb in resting position. The occurrence and types of fusimotor effects were assessed by comparing test to control responses. The main finding of the present investigation was the great variability in type and size of the fusimotor effects evoked by different ipsi- and contralateral reflex stimuli. Both ipsi- and contralateral stimulations gave rise to predominantly dynamic, predominantly static or mixed static and dynamic fusimotor reflexes. In the same preparation, a given reflex stimulus often caused different reflex responses in different triceps surae primary spindle afferents. In the same afferent unit, different reflex stimuli usually produced fusimotor effects which differed from each other in type and/or size. In general, contralateral whole limb extension and stretch of contralateral PBSt muscles were more potent as reflex stimuli than stretch of the ipsilateral PBSt muscle. Stretch of the contralateral triceps surae muscle was, but for a few afferent units, ineffective as reflexogenic stimulus. It is concluded that the individualized receptive profiles of the primary muscle spindle afferents, which have been postulated in earlier investigations where the effects of different stimuli have been investigated on different cell populations, still seems to hold good when the stimuli are tested on the same units. The individuality of the receptive profiles of gamma-motoneurones is discussed in relation to different motor control hypotheses.     

Spread of herpes simplex virus in lymph nodes after experimental infection of mice

Herpes simplex virus was frequently isolated from ipsilateral popliteal lymph nodes after percutaneous inoculation of the dorsal face of the footpad, and from ipsi- and contralateral submandibular lymph nodes after percutaneous inoculation of the cheek or the orofacial area of mice. Virus was detected only on very rare occasion in nondraining lymph nodes (inguinal or axillary) or in contralateral popliteal lymph nodes, but was frequently isolated in contralateral lumbar lymph nodes after footpad inoculation. The presence of virus in lymph nodes paralleled or followed the invasion of ipsilateral sensory ganglia and was associated with dissemination of virus in contralateral sensory ganglia after unilateral inoculation. In older mice virus was detected only occasionally in lymph nodes and dissemination of virus in contralateral sensory ganglia was generally not observed. The results suggest that lymphatic spread may contribute to dissemination of virus in contralateral sensory ganglia after unilateral inoculation of mice.     

Intra- and extraneuronal changes of immunofluorescence staining for TNF-alpha and TNFR1 in the dorsal root ganglia of rat peripheral neuropathic pain models

1. Several lines of evidence suggest that cytokines and their receptors are initiators of changes in the activity of dorsal root ganglia (DRG) neurons, but their cellular distribution is still very limited or controversial. Therefore, the goal of present study was to investigate immunohistochemical distribution of TNF-alpha and TNF receptor-1 (TNFR1) proteins in the rat DRG following three types of nerve injury. 2. The unilateral sciatic and spinal nerve ligation as well as the sciatic nerve transection were used to induce changes in the distribution of TNF-alpha and TNFR1 proteins. The TNF-alpha and TNFR1 immunofluorescence was assessed in the L4-L5 DRG affected by nerve injury for 1 and 2 weeks, and compared with the contralateral ones and those removed from naive or sham-operated rats. A part of the sections was incubated for simultaneous immunostaining for TNF-alpha and ED-1. The immunofluorescence brightness was measured by image analysis system (LUCIA-G v4.21) to quantify immunostaining for TNF-alpha and TNFR1 in the naive, ipsi- and contralateral DRG following nerve injury. 3. The ipsilateral L4-L5 DRG and their contralateral counterparts of the rats operated for nerve injury displayed an increased immunofluorescence (IF) for TNF-alpha and TNFR1 when compared with DRG harvested from naive or sham-operated rats. The TNFalpha IF was increased bilaterally in the satellite glial cells (SGC) and contralaterally in the neuronal nuclei following sciatic and spinal nerve ligature. The neuronal bodies and their SGC exhibited bilaterally enhanced IF for TNF-alpha after sciatic nerve transection for 1 and 2 weeks. In addition, the affected DRG were invaded by ED-1 positive macrophages which displayed simultaneously TNFalpha IF. The ED-1 positive macrophages were frequently located near the neuronal bodies to occupy a position of the satellites. 4. The sciatic and spinal nerve ligature resulted in an increased TNFR1 IF in the neuronal bodies of both ipsi- and contralateral DRG. The sciatic nerve ligature for 1 week induced a rise in TNFR1 IF in the contralateral DRG neurons and their SGC to a higher level than in the ipsilateral ones. In contrast, the sciatic nerve ligature for 2 weeks caused a similar increase of TNFR1 IF in the neurons and their SGC of both ipsi- and contralateral DRG. The spinal nerve ligature or sciatic nerve transection resulted in an increased TNFR1 IF located at the surface of the ipsilateral DRG neurons, but dispersed IF in the contralateral ones. In addition, the SGC of the contralateral in contrast to ipsilateral DRG displayed a higher TNFR1 IF. 5. Our results suggest more sources of TNF-alpha protein in the ipsilateral and contralateral DRG following unilateral nerve injury including macrophages, SGC and primary sensory neurons. In addition, the SGC and macrophages, which became to be satellites, are well positioned to regulate activity of the DRG neurons by production of TNF-alpha molecules. Moreover, the different cellular distribution of TNFR1 in the ipsi- and contralateral DRG may reflect different pathways by which TNF-alpha effect on the primary sensory neurons can be mediated following nerve injury.     

Intra- and Extraneuronal Changes of Immunofluorescence Staining for TNF- and TNFR1 in the Dorsal Root Ganglia of Rat Peripheral Neuropathic Pain Models

1. Several lines of evidence suggest that cytokines and their receptors are initiators of changes in the activity of dorsal root ganglia (DRG) neurons, but their cellular distribution is still very limited or controversial. Therefore, the goal of present study was to investigate immunohistochemical distribution of TNF-α and TNF receptor-1 (TNFR1) proteins in the rat DRG following three types of nerve injury.2. The unilateral sciatic and spinal nerve ligation as well as the sciatic nerve transection were used to induce changes in the distribution of TNF-α and TNFR1 proteins. The TNF-α and TNFR1 immunofluorescence was assessed in the L4-L5 DRG affected by nerve injury for 1 and 2 weeks, and compared with the contralateral ones and those removed from naive or sham-operated rats. A part of the sections was incubated for simultaneous immunostaining for TNF-α and ED-1. The immunofluorescence brightness was measured by image analysis system (LUCIA-G v4.21) to quantify immunostaining for TNF-α and TNFR1 in the naive, ipsi- and contralateral DRG following nerve injury.3. The ipsilateral L4-L5 DRG and their contralateral counterparts of the rats operated for nerve injury displayed an increased immunofluorescence (IF) for TNF-α and TNFR1 when compared with DRG harvested from naive or sham-operated rats. The TNFα IF was increased bilaterally in the satellite glial cells (SGC) and contralaterally in the neuronal nuclei following sciatic and spinal nerve ligature. The neuronal bodies and their SGC exhibited bilaterally enhanced IF for TNF-α after sciatic nerve transection for 1 and 2 weeks. In addition, the affected DRG were invaded by ED-1 positive macrophages which displayed simultaneously TNFα IF. The ED-1 positive macrophages were frequently located near the neuronal bodies to occupy a position of the satellites.4. The sciatic and spinal nerve ligature resulted in an increased TNFR1 IF in the neuronal bodies of both ipsi- and contralateral DRG. The sciatic nerve ligature for 1 week induced a rise in TNFR1 IF in the contralateral DRG neurons and their SGC to a higher level than in the ipsilateral ones. In contrast, the sciatic nerve ligature for 2 weeks caused a similar increase of TNFR1 IF in the neurons and their SGC of both ipsi- and contralateral DRG. The spinal nerve ligature or sciatic nerve transection resulted in an increased TNFR1 IF located at the surface of the ipsilateral DRG neurons, but dispersed IF in the contralateral ones. In addition, the SGC of the contralateral in contrast to ipsilateral DRG displayed a higher TNFR1 IF.5. Our results suggest more sources of TNF-α protein in the ipsilateral and contralateral DRG following unilateral nerve injury including macrophages, SGC and primary sensory neurons. In addition, the SGC and macrophages, which became to be satellites, are well positioned to regulate activity of the DRG neurons by production of TNF-α molecules. Moreover, the different cellular distribution of TNFR1 in the ipsi- and contralateral DRG may reflect different pathways by which TNF-α effect on the primary sensory neurons can be mediated following nerve injury.     

Fusimotor reflex profiles of individual triceps surae primary muscle spindle afferents assessed with multi-afferent recording technique.

The experiments were performed on 21 cats anaesthetized with alpha-chloralose. The aim of the study was to investigate sets of simultaneously recorded spindle afferents (2-4 in each set) from the triceps surae muscle (GS) with respect to the pattern of fusimotor reflex effects evoked by different types of ipsi- and contralateral reflex stimulation. The afferents' responses to sinusoidal stretching of the GS muscle were determined and the fusimotor reflex effects were assessed by comparing the afferent responses (i.e. the mean rate of firing and the depth of modulation) elicited during reflex stimulation with those evoked in absence of any reflex stimulus. Natural of electrical activations of ipsi- and contralateral muscle, skin and joint receptor afferents were used as reflex stimuli. The spindle afferents were influenced by several modalities and from wide areas, with a majority responding to both ipsi- and contralateral stimuli. A particular reflex stimulus often caused different effects on different afferents, and the various reflex stimuli seldom gave similar effects on a particular afferent. Multivariate analysis revealed that the variation in response profiles among simultaneously recorded afferents were as great as between afferents recorded on different occasions. This suggests that the individualized response prifiles, observed in earlier investigations, represent a very diversified reflex control of the spindle primary afferents, and are not a reflection of changes in the setting of the spinal interneuronal network, occurring during the time interval between the recordings of different units. Also, there was no relation between the conduction velocity of the afferents and the reflex profiles of the afferents, but non-linear relations were found between effects elicited by different types of stimuli. Indications were also found that it may be possible to separate the population of GS muscle spindles into subgroups, according to the fusimotor effects exhibited by activation of various categories of ipsi- and contralateral receptor afferents. It is concluded that one possible way of making the very complex reflex system controlling the muscle spindles intelligible may be a combination of multiple simultaneous recordings of spindle afferents and multivariate analysis.     

Dopamine and Serotonin Metabolism in Brain Sites Ipsi- and Contralateral to Direction of Conditioned Turning in Rats

Concentrations of dopamine, serotonin, and some of their metabolites were analyzed by means of HPLC in brain samples obtained from rats operantly conditioned to turn in circles to obtain water reinforcement. In experiment 1 using Wistar rats, no differences in the levels of transmitters or metabolites were detected between brain samples (frontal cortex, ventral striatum, dorsal striatum, septum, amygdala, substantia nigra) from the hemispheres located ipsi- and contralateral to the direction of turning. A higher dopamine metabolism (indicated by higher metabolite/transmitter ratios) in ventral striatum, dorsal striatum, and amygdala was found after 15 min than after 5 min of turning in both hemispheres. A higher dopamine metabolism was found in water-deprived rats compared to nondeprived rats independently of whether or not deprived rats were trained to turn for water reinforcement. In two additional experiments, no differences in dopamine metabolism were found between the ipsi- and contralateral striatum of Wistar rats after 25 min and Sprague-Dawley rats after 10 min of operantly conditioned turning. The present results confirm that dopamine metabolism can change with different behavioral or physiological states; they do not support the hypothesis that conditioned turning is correlated with asymmetrical changes in the metabolism of dopamine or serotonin in the brain.     

Ontogeny of afferents to the fetal rat cerebellum.

Afferents to the fetal rat cerebellum have been studied in fixed tissue with the fluorescent tracer, 1,1'-dioctadecyl-3,3,3',3'tetramethylindocarbocyanine perchlorate (DiI). The dye was applied to the cerebellar anlage at ages from embryonic day (E) 12 to birth (P0). Central processes of vestibular ganglion cells were found to be the first identifiable afferents to the cerebellum, being present at least by E13 and perhaps as early as E12. Ipsilateral spinocerebellar fibres may be labelled from E15, vestibular nuclei (both ipsi- and contralateral) also from E15, while contralateral inferior olivary nuclei could not be retrogradely labelled until E17. Trigeminocerebellar neurons in the interpolaris subnucleus of the nucleus of the trigeminal spinal tract and neurons of the lateral reticular nucleus were not labelled until E22 and P0, respectively. Finally, contralateral pontine nuclei were retrogradely labelled from the cerebellum after birth.     

Connectivity of the salamander pretectum: an in-vitro (whole-brain) intracellular tracing study

The amphibian optic tectum and pretectum have been analyzed in detail anatomically and physiologically, and a specific model for tecto-pretectal interaction in the context of the visual guidance of behavior has been proposed. However, anatomical evidence for this model, particularly the precise pattern of pretecto-tectal connectivity, is lacking. Therefore, we stained pretectal neurons intracellularly in an in-vitro preparation of the salamanders Plethodon jordani and Hydromantes genei. Our results demonstrate that the projections of neurons of the nucleus praetectalis profundus are divergent and widespread. Individual neurons may project divergently to telencephalic (ipsilateral amygdala and striatum), diencephalic (ipsi-and contralateral thalamus, contralateral pretectum), and mesencephalic (ipsi- and contralateral tectum and tegmentum) centers, and to the ipsi- and contralateral medulla oblongata and rostral spinal cord. The projection of pretectal cells to the optic tectum is bilateral; axonal structures do not show discernible patterns and are present in all layers of the superficial white matter. A classification of pretectal neurons on the basis of axonal termination pattern or dendritic arborization has not been possible. Our results do not support the hypothesis that a distinct class of pretectal neurons projects to a particular subset of tectal cells. Rather, the pretectum appears to influence the tectum indirectly, acting either on retinal afferents or modulating inhibitory interneurons.     

Distribution of the LPa3 and PPa3 neuronal processes in the pedal ganglia of the edible snail

By means of intracellular injection of the dye Lucifer yellow processes were revealed of the snail command neurones of escape behaviour LPa3 and RPa3 in pedal nerves ipsilateral to these neurones. A process of the neurone LPa3 was also found in the contralateral Nervus cutaneus pedalis secundus. Blockade of central chemical synapses by cadmium chloride did not lead to disappearance of motor reactions evoked by electrical stimulation of LPa3 and RPa3 neurones both on ipsi- and contralateral sides of the animal foot; this allowed to suggest a presence in the contralateral muscular pedal nerves of these neurones processes unrevealed by the used dyeing method.     

Changes in evoked cortico-motor responses in the rat during aging and after partial decortication

Some changes of the organization of cortical motor representations, which were revealed by means of the intracortical microstimulation (ICMS) in aged rats after unilateral partial decortication, were true consequences of the decortication, but had no significant relationship to the aging. Distributions of latent periods of contralateral hind-leg EMG-responses to the ICMS had no significant shifts both during aging and after the surgery. Values of short-latency responses of ipsilateral proximal and axial muscles to the ICMS were in late time periods, from 8 to 16 months after surgery, significantly lower than ones of contralateral homonymous muscles. It is supposed, that ipsi- and bilateral short-latency responses to the ICMS in proximal and axial muscles of operated rats during late time periods are relayed through some pathways from the brain stem to the spinal cord.     

Control of conduction of afferent impulses across the lateral geniculate body by the side of the superior colliculus in alert rabbits

On alert rabbits it was shown that the stimulation of the superior colliculus inhibit visual evoked potential both of the ipsi- and contralateral geniculate body. Besides, the suppression of amplitude of the contralateral geniculate body's evoked potential was more significant than amplitude of the ipsilateral geniculate body's evoked potential. On the basis of the obtained results the authors suppose that superior colliculus is involved in organization of the effect of saccadic suppression of lateral geniculate body's visual responses.     

Optic chiasm presentation of Semaphorin6D in the context of Plexin-A1 and Nr-CAM promotes retinal axon midline crossing

At the optic chiasm, retinal ganglion cells (RGCs) project ipsi- or contralaterally to establish the circuitry for binocular vision. Ipsilateral guidance programs have been characterized, but contralateral guidance programs are not well understood. Here, we identify a tripartite molecular system for contralateral RGC projections: Semaphorin6D (Sema6D) and Nr-CAM are expressed on midline radial glia and Plexin-A1 on chiasm neurons, and Plexin-A1 and Nr-CAM are also expressed on contralateral RGCs. Sema6D is repulsive to contralateral RGCs, but Sema6D in combination with Nr-CAM and Plexin-A1 converts repulsion to growth promotion. Nr-CAM functions as a receptor for Sema6D. Sema6D, Plexin-A1, and Nr-CAM are all required for efficient RGC decussation at the optic chiasm. These findings suggest a mechanism by which a complex of Sema6D, Nr-CAM, and Plexin-A1 at the chiasm midline alters the sign of Sema6D and signals Nr-CAM/Plexin-A1 receptors on RGCs to implement the contralateral RGC projection.     

Spatial summation of heat induced pain within and between dermatomes

The aim was to study spatial summation within and between ipsi- and contralateral dermatomes at different painful temperatures. For heat stimulation we used a computer controlled thermofoil based thermode. The thermode area could be varied in five discrete steps from 3.14 to 15.70 cm2. When we applied the stimuli within a dermatome, the mean heat pain threshold decreased significantly from 45.6 to 43.5 C as the area was increased from minimum (3.14 cm2) to maximum (15.70 cm2). When the areas were increased involving different dermatomes (both ipsi- or contralateral), we found similar decreases in pain threshold. Spatial summation was also found within and between dermatomes at supra-threshold temperatures (46, 48, 50 C).The study shows that spatial summation of pain is most likely a mechanism acting across segments and is existing from pain threshold to tolerance.     

Bilateral brainstem connections of the rat supratrigeminal region

Efferent and afferent connections of the supratrigeminal region were studied in the rat using iontophoretically delivered horseradish peroxidase and Phaseolus vulgaris leuco-agglutinin. Projections of supratrigeminal efferents were found to the contralateral supratrigeminal region, to the ipsi- and contralateral trigeminal motor nuclei and the medullary reticular formation, and to the ipsilateral facial and hypoglossal motor nuclei. Neurons projecting to the supratrigeminal region were located in the contralateral supratrigeminal nucleus, in the ipsilateral mesencephalic trigeminal nucleus and bilaterally in the medullary reticular formation. This organization is discussed with respect to bilateral oral motor control mechanisms.     

Autophosphorylation is essential for the in vivo function of the Lotus japonicus Nod factor receptor 1 and receptor-mediated signalling in cooperation with Nod factor receptor 5

Soil-living rhizobia secrete lipochitin oligosaccharides known as Nod factors, which in Lotus japonicus are perceived by at least two Nod-factor receptors, NFR1 and NFR5. Despite progress in identifying molecular components critical for initial legume host recognition of the microsymbiont and cloning of downstream components, little is known about the activation and signalling mechanisms of the Nod-factor receptors themselves. Here we show that both receptor proteins localize to the plasma membrane, and present evidence for heterocomplex formation initiating downstream signalling. Expression of NFR1 and NFR5 in Nicotiana benthamiana and Allium ampeloprasum (leek) cells caused a rapid cell-death response. The signalling leading to cell death was abrogated using a kinase-inactive variant of NFR1. In these surviving cells, a clear interaction between NFR1 and NFR5 was detected in vivo through bimolecular fluorescence complementation (BiFC). To analyse the inter- and intramolecular phosphorylation events of the kinase complex, the cytoplasmic part of NFR1 was assayed for in vitro kinase activity, and autophosphorylation on 24 amino acid residues, including three tyrosine residues, was found by mass spectrometry. Substitution of the phosphorylated amino acids of NFR1 identified a single phosphorylation site to be essential for NFR1 Nod-factor signalling in vivo and kinase activity in vitro. In contrast to NFR1, no in vitro kinase activity of the cytoplasmic domain of NFR5 was detected. This is further supported by the fact that a mutagenized NFR5 construct, substituting an amino acid essential for ATP binding, restored nodulation of nfr5 mutant roots.     

A cytochemical study of binaurally converging connections in the nuclei of the cat superior olive]

Experiments of binaurally converging connections on the level of the superior olive nuclei was carried out on anesthetized cats by the method of quantitative cytospectrometry. A considerable increase in the cytoplasmic RNA content in the neurons of the ipsi- and contralateral medial and lateral nuclei was observed following a 2-hour monaural stimulation by rhythmical sound (noise) signals. The volume of the functioning neurons of the nuclei under study showed either no significant change or increased. The data obtained demonstrated the nature of functional organization of the binaurally converging connections.     

Participation of the GABA B receptors in presynaptic inhibition of the spinal cord descending projections fibers in the frog Rana ridibunda

(-)-Baclophen was found to depress in a dose-dependent and reversible way the excitatory post-synaptic potentials (EPSPS) of motor neurons and the ventral root potentials evoked by stimulation of fibres of the ipsi- and contralateral ventral columns. The (-)-baclophen depressing effect could be eliminated with saclophen. Picrotoxin eliminated the depressing effect of the GABA on the descending EPSPS. Depressing effects of (-)-baclophen and GABA upon the ventral root potentials were also shown. The data obtained in pharmacological analysis corroborate to a certain extent existence of the GABAB receptor presynaptic inhibition in descending fibres monosynaptically corrected with the spinal cord motor neurons in the frog Rana ridibunda.