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  • 1
    Electronic Resource
    Electronic Resource
    Quantitative ultrastructural observations on the inhibited recovery of the hypoglossal nucleus from the axotomy response when regeneration of the hypoglossal nerve is prevented (1976)
    Springer
    Experimental brain research 26 (1976), S. 141-150 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Inhibited regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron micrographs of the left hypoglossal nucleus were quantitatively analyzed in adult rats 52 to 98 days after transection of the left hypoglossal nerve and implantation of the proximal stump into the already innervated ipsilateral sternomastoid muscle, a procedure which prevented the transected nerve from regenerating. Many presynaptic boutons with clear spherical synaptic vesicles and symmetrical synapses were lost from the injured perikarya and dendrites. Some perikarya and dendrites (and, rarely, boutons) became electron dense, and astrocyte or microglial sheaths partly surrounded them. Numbers of dendrite profiles in the neuropil decreased. These statistically significant effects persisted throughout the postoperative period, whereas after axotomy with unimpeded nerve regeneration, these features would have returned to normal by 84 days postoperatively. It was therefore suggested that their recovery depended upon successful regeneration and reconnection of the hypoglossal nerve with the tongue. Subsurface cisterns, and profiles containing unusual inclusions, were numerically normal 52 to 98 days postoperatively, so it was suggested that their early response and recovery after simple axotomy might be entirely dependent on nerve disconnection and not on nerve reconnection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238278
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  • 2
    Electronic Resource
    Electronic Resource
    Responses of boutons and glia in the hypoglossal nucleus to injection of α- or β-bungarotoxin into the tongue (1979)
    Springer
    Experimental brain research 36 (1979), S. 387-392 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Boutons ; Glia ; Bungarotoxins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Somatic bouton frequencies, and percent coverage of perikaryal circumference by boutons, microglia, astrocytes, or other structures, were measured on electron micrographs of the left hypoglossal nucleus of adult male albino rats after injections, into the left side of the tongue, of either α-bungarotoxin or β-bungarotoxin in a buffered saline solution (PBS). Control rats were injected with PBS alone. Values from bungarotoxin-treated rats were compared statistically with those from controls and normal rats. Somatic bouton frequencies and percent coverage of perikarya by boutons, were reduced in all the β-bungarotoxin-treated rats when compared with control or normal values. The control values were normal. In α-bungarotoxin-treated rats somatic bouton frequencies were reduced in four of the six rats, and percent coverage of perikarya by boutons in three of the six rats. A few microglia (up to 3.1% coverage) were present in β-bungarotoxin-treated rats, but none were found in α-bungarotoxin-treated rats, controls, or normals. Percent coverage of perikarya by astrocyte was significantly much higher than normal in bungarotoxin-treated rats, and higher than normal in the controls. Conversely, percent coverage by other structures was reduced in bungarotoxin-treated rats and controls. It is suggested that boutons and glia respond to different stimuli, and that the behaviour of the microglia is dependent on the condition of the hypoglossal nerve and not on bouton behaviour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238920
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  • 3
    Electronic Resource
    Electronic Resource
    Membrane-associated adenosine triphosphatase in normal and injured hypoglossal nuclei (1978)
    Springer
    Experimental brain research 33 (1978), S. 213-225 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; ATP-ase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The hypoglossal nuclei of adult male albino rats, either normal, or from 1 to 70 days after left hypoglossal nerve transection, were studied cytochemically with a lead method for sodium- and potassium-activated membrane ATP-ase, using light and electron microscopy. Reaction product was measured at the light microscopical level by microdensitometry, and significance determined statistically. Light microscopy revealed a brown reaction product in the neuropil, but none in cell bodies. Blood vessel walls were more strongly coloured. Reaction product was undiminished by ouabain pre-incubation, or by incubation without sodium or potassium, or by incubation with calcium instead of magnesium. Reaction product was diminished by absence of magnesium if calcium was also absent, and abolished if sections were boiled before incubation, or if substrate was absent. Axotomy caused a statistically significant increase in neuropil reaction product in injured nuclei, maximal at 35 days postoperatively, and subsequently decreasing to normal at 70 days. Electron microscopy showed a predominantly surface membrane reaction product, with occasional positive intracellular cisternae. Basal lamina and intra-endothelial vacuoles were also positive. Axotomy resulted in the arrival and disappearance of microglia (2 to 35 days), followed by astrocyte hypertrophy (35 days), and increase in thickness and homogeneity of surface membrane reaction product. The results suggest the presence of one or more calcium- or magnesium-dependent membrane ATP-ases. The peak of the increase after axotomy is probably partly attributable to hypertrophic astrocytes, and partly to the surfaces of neuronal processes. Increase of membrane movements might explain such enzyme activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238061
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  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructural data, with special reference to bouton/glial relationships, from the hypoglossal nucleus after a second axotomy of the hypoglossal nerve (1979)
    Springer
    Experimental brain research 36 (1979), S. 107-118 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Ultrastructure ; Second axotomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The left hypoglossal nerve of adult male albino rats was prevented from regenerating to the tongue after a distal axotomy by implanting the proximal stump into normally innervated left sternomastoid muscle. Eighty-four days after implantation, the hypoglossal nerve was transected again and its regeneration to the tongue unimpeded. From 8 to 70 days after this second axotomy the left hypoglossal nuclei were processed for quantitative ultrastructural analysis. The first aim of this study was to compare regeneration success in the hypoglossal nucleus after second axotomy with that accompanying outgrowth of the hypoglossal nerve into denervated sternomastoid muscle. During quantitative analysis a second aim developed, of elucidating bouton/glial relationships. The second axotomy induced loss and return of subsurface cisterns, dispersal and reassembly of Nissl substance, increase and decrease of microglial numbers, slight further loss and partial return of boutons with clear spherical vesicles and symmetrical synapses, slight increase and decrease of boutons with clear flat vesicles and symmetrical synapses, regrowth of retracted dendrites and restoration of their synapses, and gradual diminution of numbers of electron-dense neurones and dendrites. Astrocytes remained hypertrophied throughout. When compared with events in the hypoglossal nucleus accompanying innervation of denervated sternomastoid muscle by the hypoglossal nerve, the results suggest (1) that regeneration of the hypoglossal nerve to its own tongue muscle instead of to a foreign muscle caused no acceleration of recovery in the hypoglossal nucleus, and (2) that the microglial response is dependent on nerve integrity and not on bouton behaviour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238471
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  • 5
    Electronic Resource
    Electronic Resource
    A quantitative study of subsurface cisterns and their relationships in normal and axotomized hypoglossal neurones (1975)
    Springer
    Experimental brain research 22 (1975), S. 175-183 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; Subsurface cisterns
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A quantitative ultrastructural survey was made of subsurface cisterns and their association with overlying structures in the left hypoglossal nucleus of normal rats, and rats which had received left hypoglossal axotomies 7–84 days previously. Subsurface cisterns in normal rats occurred in some hypoglossal neurones, and, sporadically, in proximal dendrites. They were mostly subsynaptic, and often associated with Nissl substance. From 7–14 days postoperatively, when many somatic boutons temporarily lost contact with the perikaryal surface, and were replaced by a microglial sheath, the percentage of perikaryon with underlying cistern was significantly reduced. The Nissl substance was also dispersed at this stage, and not restored until 28 days postoperatively. At 21 days normal percentages of subsurface cistern were restored, but the cisterns were now mostly subastrocytic, an astrocytic sheath having replaced the microglial sheath. From 63 days onwards the cisterns were mostly subsynaptic again as boutons returned to the regenerating perikarya and the temporary astrocytic sheath disappeared. It is suggested that subsurface cisterns might alter the overlying perikaryal surface in some way during neuronal regeneration, causing certain boutons to adhere there.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237687
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  • 6
    Electronic Resource
    Electronic Resource
    An ultrastructural study of normal and injured hypoglossal nuclei after injection of horseradish peroxidase (1975)
    Springer
    Experimental brain research 23 (1975), S. 463-470 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Axotomy ; Horseradish peroxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The left hypoglossal nuclei of normal rats, and rats which had received left hypoglossal nerve axotomies 7–21 days previously, were studied by electron microscopy after injection of horseradish peroxidase as a marker of extracellular space and pinocytosis. Quantitative analysis showed that the number of pinocytotically-derived structures in presynaptic boutons was significantly increased in rats at 7, 14, and 21 days after axotomy when compared with normal rats. It was suggested that presynaptic boutons which became detached from injured neurones retracted by a membrane cycling mechanism involving pinocytotic uptake of bouton plasmalemma, without compensatory membrane production elsewhere. It was confirmed that the channels in the microglial cells communicated with the extracellular space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234915
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  • 7
    Electronic Resource
    Electronic Resource
    Ultrastructural responses of the hypoglossal nucleus to the presence in the tongue of botulinum toxin, a quantitative study (1977)
    Springer
    Experimental brain research 30 (1977), S. 313-321 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Botulinum toxin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural effects of local injection of botulinum toxin into the left half of the tongue of the rat, were studied quantitatively 35 days postoperatively in the left hypoglossal nucleus. The results showed (1) a decrease in somatic and neuropil bouton numbers because of loss of boutons with symmetrical synapses and clear spherical synaptic vesicles, (2) a decrease in the numbers of dendrite profiles in the neuropil, (3) an increase in the proportion of dendrites and boutons with unusual inclusions, suggestive of profile retraction, (4) an increase in the proportion of profiles which were unusually electron-dense, (5) an increase in the amount of astrocyte, and a growth of astrocyte sheaths around bouton-free neurone surfaces, (6) the presence of occasional microglia, and (7) subastrocytic subsurface cisterns. Control rats injected with boiled toxin had no responses except (3) and (4) above, and then only to a modest extent, possibly due to mechanical damage of a few axons or terminals at the time of injection, or to insufficient inactivation of the toxin by boiling. The results were compared with those at 35 days after axotomy, and it was concluded that botulinum toxin, which interrupts neuromuscular transmission, elicits the same responses in the hypoglossal neurones, as does transection of the hypoglossal nerve, even though earlier studies had discovered no glial replication after botulinum toxin, in contrast to axotomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237258
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  • 8
    Electronic Resource
    Electronic Resource
    Responses in the hypoglossal nucleus to delayed regeneration of the transected hypoglossal nerve, a quantitative ultrastructural study (1977)
    Springer
    Experimental brain research 29 (1977), S. 219-231 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Delayed regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron micrographs of the left hypoglossal nucleus of adult male albino rats were quantitatively analyzed from 9–70 days after allowing the transected left hypoglossal nerve to regenerate after an 84 day delay. Delay was achieved by implanting the proximal stump into already innervated sternomastoid muscle, where no regeneration occurred. Regeneration was then allowed by denervating the sternomastoid. During the regenerative period the initially high number of abnormally electron dense perikarya and dendrites decreased to almost normal values, but no cell removal was seen. This suggested that the degenerate appearance of many profiles after prolonged prevention of regeneration, was reversible. The neuropil bouton and dendrite counts, and the numbers of synapsing boutons per dendrite, increased steadily to normal values from the low values of suppressed regeneration. Somatic bouton frequencies, even though already low, decreased further at 32 days, and later increased but not to normal values. The decrease at 32 days coincided with the loss of many subsurface cisterns, and dispersion of Nissl substance, all suggestive of chromatolysis. Later the subsurface cisterns and Nissl substance returned. It was suggested that the delay of complete recovery of somatic bouton frequencies might be because of lack of sensory information from the denervated muscle into which the hypoglossal nerve was regenerating, or because of abnormally low starting values for the recovery phase. Astrocyte (or, occasionally microglial) sheaths persisted along boutonfree perikaryal surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237043
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  • 9
    Electronic Resource
    Electronic Resource
    Resident–Intruder Trait Aggression is Associated with Differences in Lysine Vasopressin and Serotonin Receptor 1A (5-HT1A) mRNA Expression in the Brain of Pre-Pubertal Female Domestic Pigs (Sus scrofa) (2005)
    Oxford, UK : Blackwell Science Ltd
    Journal of neuroendocrinology 17 (2005), S. 0 
    Details
    ISSN: 1365-2826
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Aggressive behaviour exhibited by domestic pigs following encounters with unfamiliar individuals is a serious welfare and economical problem. Aggression resulting in skin lesions is similarly prevalent in prepubertal pigs of either sex. Little is known about the neural circuits and neuropeptides that control aggression in the pig. Because there is evidence for the involvement of the vasopressin and serotonergic systems in the regulation of aggressive behaviour in male mammals, we sought differences using quantitative in situ hybridisation of vasopressin and serotonin 1A receptor (5-HT1A) mRNA expression within specific brain regions of aggressive and nonaggressive prepubertal female pigs. The number of cells expressing vasopressin mRNA was significantly higher in aggressive pigs in the medial amygdala, lateral septum (LS) and showed a similar trend in the bed nucleus of the stria terminalis (BnST) but not the paraventricular nucleus (PVN) or supraoptic nucleus. The 5-HT1A receptor was widely expressed through the porcine brain and a significantly lower intensity (silver grain density) of 5-HT1A mRNA expression was observed in the BnST. In the medial amygdala and LS fewer cells expressed 5-HT1A mRNA in aggressive pigs but no differences were found in the PVN. In the absence of inbred strains or selection lines, these findings have shown that prior identification of phenotypic behavioural extremes in a population in advance of neural studies is a useful technique. Moreover, these findings support a central role for vasopressin and serotonin in the mediation of high trait aggression in prepubertal female pigs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2826.2005.01359.x
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  • 10
    Electronic Resource
    Electronic Resource
    Retraction and Expansion of the Dendritic Tree of Motor Neurones of Adult Rats induced in vivo (1971)
    [s.l.] : Nature Publishing Group
    Nature 233 (1971), S. 273-275 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Fig. 1 The number of dendrites crossing concentric shells is expressed graphically against the radius of the shell. ?, Normal right side; O, treated left side of a rat 6 weeks after botulinum toxin. Twenty neurones were measured on each side and the mean values are shown, with standard errors. ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/233273a0
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