Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Effects of visual experience on the maturation of the efferent system to the corpus callosum (1979)
    [s.l.] : Nature Publishing Group
    Nature 280 (1979), S. 231-234 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Fig. 1 Computer microscope26 charts of the distribution of HRP-labelled callosal neurones in 80-?? thick coronal sections at comparable rostrocaudal levels of the visual cortex in different animals. Multiple, 0.5-? injections of HRP (Boehringer grade I, 33% in sterile saline) were placed in the ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/280231a0
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The anatomical substrate of callosal messages from SI and SII in the cat (1979)
    Springer
    Experimental brain research 35 (1979), S. 295-314 
    Details
    ISSN: 1432-1106
    Keywords: Interhemispheric communication ; Callosal efferent zones ; Somatosensory cortex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Horseradish peroxidase (HRP) was injected into the first (SI) or second (SII) somatosensory areas of 21 adult cats. The radial and tangential (normal and parallel to the pial surface, respectively) distribution and morphology of the callosal neurons were studied. HRP injections were combined with single unit recording in the contralateral cortex in order to determine which part of the somatosensory periphery is represented within the regions containing callosal neurons, the callosal (efferent) zones, in SI and SII. The callosal zone of SI extends over the trunk and part of the forepaw representation. In the forepaw and hindlimb representations callosal neurons projecting only to the contralateral SII are found, while in the trunk representation callosal neurons projecting to contralateral SI or SII are found. The callosal zone in SII extends widely throughout the forepaw representation in this area and projects to the contralateral SII but not to SI. In both SI and SII the callosal neurons are mainly located in layer III. A few of them are also found in layer VI. They are very rare in other layers. Callosal neurons in layer III are mostly pyramidal but exceptionally stellate; in layer VI they are pyramidal, triangular, and occasionally stellate. These data indicate that transformations of the cortical somatosensory maps are achieved in the message sent through the corpus callosum. These transformations are i) determined by the extent and location of the callosal zones and perhaps by the distribution of callosal neurons within them, ii) different in different areas, iii) different in a same area, according to the cortical targets to which they are conveyed. The existence of callosal connections originated from areas of distal forepaw representation supplies a possible anatomical substrate for those types of intermanual transfer of tactile learning which depend upon the integrity of the corpus callosum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236617
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    The postnatal development of somatosensory callosal connections after partial lesions of somatosensory areas (1981)
    Springer
    Experimental brain research 42 (1981), S. 53-62 
    Details
    ISSN: 1432-1106
    Keywords: Corpus callosum ; Somatosensory cortex ; Brain lesions ; Plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The distribution of S1 (first somatosensory area) and S2 (second somatosensory area) neurons projecting to the contralateral S2 was studied with horseradish peroxidase in normal adult cats and in cats aged between 129 and 248 days in which the injected S2 area had been deprived of some of its input by an earlier lesion (on postnatal days 3 to 30; day of birth = day 1) of ipsilateral S1, alone or combined with a lesion of contralateral S2. In animals with S1 lesions, as in the normal controls, labeled neurons were selectively distributed to the regions of the trunk representation and to parts of the forelimb and hindlimb representations; however, the normally acallosal region in the forepaw representation contained scattered labeled neurons in three of the four animals whose S1 had been lesioned during the first postnatal week. In these animals, the distribution of labeled neurons in the contralateral S2 was apparently normal. Furthermore, the additional lesion of this area during the first postnatal week (one animal) did not increase the degree of filling-in of the normally acallosal parts of S1. The partial filling-in of the acallosal parts of S1 is probably due to the preservation to adulthood of some of the callosal neurons which are present in these regions during the early postnatal life. Possibly, these neurons did not disappear (or lose their callosal axons) because the neonatal lesion (i) allowed their successful competition for terminal space in contralateral S2 or (ii) induced a reorganization of the peripheral input to this area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235729
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Emergence of callosally projecting neurons with stellate morphology in the visual cortex of the kitten (1992)
    Springer
    Experimental brain research 90 (1992), S. 346-358 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex ; Corpus callosum ; Dendrites ; Spiny stellate neurons ; Kitten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Callosally projecting neurons in areas 17 and 18 of the adult cat can be classified into two types on the basis of their dendritic morphology: pyramidal and stellate cells. The latter are nearly exclusively of the spinous type and are predominantly located in upper layer IV. Retrograde transport of the carbocyanine dye DiI, applied to the corpus callosum, showed that, up to P6, all callosally projecting neurons resemble pyramids in the possession of an apical dendrite reaching layer I. At P10, however, callosally projecting neurons with stellate morphology were found. A study was designed to distinguish whether these neurons are late in extending their axons to the corpus callosum or, alternatively, have transient apical dendrites. To this end, callosally projecting neurons were retrogradely labeled by fluorescent beads injected in areas 17 and 18 at P1–P3 and then either relabeled with DiI applied to the corpus callosum at P10 or intracellularly injected with Lucifer Yellow at P57. Double-labeled stellate and pyramidal cells were found in similar proportions to those found for the total, single-labeled population of callosally projecting neurons. It is therefore concluded that callosally projecting spiny stellate cells initially possess an apical dendrite and a pyramidal morphology. At P6, i.e. close to the time when stellate cells appear, layer IV neurons with an atrophic apical dendrite were found, suggestive of an apical dendrite in the process of being eliminated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227248
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Interconnections of the auditory cortical fields of the cat with the cingulate and parahippocampal cortices (1990)
    Springer
    Experimental brain research 80 (1990), S. 501-511 
    Details
    ISSN: 1432-1106
    Keywords: Auditory cortex ; Corticocortical connections ; Cingulate cortex ; Parahippocampal cortex ; Limbic system ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The interconnections of the auditory cortex with the parahippocampal and cingulate cortices were studied in the cat. Injections of the anterograde and retrograde tracer WGA-HRP were performed, in different cats (n = 9), in electrophysiologically identified auditory cortical fields. Injections in the posterior zone of the auditory cortex (PAF or at the PAF/AI border) labeled neurons and axonal terminal fields in the cingulate gyrus, mainly in the ventral bank of the splenial sulcus (a region that can be considered as an extension of the cytoarchitectonic area Cg), and posteriorly in the retrosplenial area. Labeling was also present in area 35 of the perirhinal cortex, but it was sparser than in the cingulate gyrus. Following WGA-HRP injection in All, no labeling was found in the cingulate gyrus, but a few neurons and terminals were labeled in area 35. In contrast, no or very sparse labeling was observed in the cingulate and perirhinal cortices after WGA-HRP injections in the anterior zone of the auditory cortex (AI or AAF). A WGA-HRP injection in the cingulate gyrus labeled neurons in the posterior zone of the auditory cortex, between the posterior ectosylvian and the posterior suprasylvian sulci, but none was found more anteriorly in regions corresponding to AI, AAF and AII. The present data indicate the existence of preferential interconnections between the posterior auditory cortex and the limbic system (cingulate and parahippocampal cortices). This specialization of posterior auditory cortical areas can be related to previous observations indicating that the anterior and posterior regions of the auditory cortex differ from each other by their response properties to sounds and their pattern of connectivity with the auditory thalamus and the claustrum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227991
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Morphology of visual callosal neurons with different locations, contralateral targets or patterns of development (1993)
    Springer
    Experimental brain research 94 (1993), S. 393-404 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex ; Development ; Dendrites ; Corpus callosum ; Interhemispheric connections ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In kittens, callosally projecting neurons were labeled by retrograde transport of FITC- (fluorescein isothiocyanate)- and TRITC- (tetramethylrhodamine isothiocyanate)-conjugated latex microspheres injected in two different visual areas (17, 17/18, 19, or postero-medial lateral suprasylvian; PMLS) at postnatal day 3. At postnatal day 57 more than 1200 labeled neurons in visual cortical areas were intracellularly injected with 3% lucifer yellow (LY) in perfusion-fixed slices of the contralateral hemisphere. The distribution of labeled neurons was charted, and LY-filled neurons were classified on the basis of their area and layer of location, and dendritic pattern. The dendritic arbors of 120 neurons were computer reconstructed. For the basal dendrites of supragranular pyramidal neurons a statistical analysis of number of nodes, internodal and terminal segment lengths, and total dendritic length was run relative to the area of location and axonal projection. Connections were stronger between homotopic than between heterotopic areas. Overall tangential and laminar distributions depended on the area injected. Qualitative morphological differences were found among callosally projecting neurons, related to the area of location, not to that of projection. In all projections from areas 17 and 18, pyramidal and spinous stellate neurons were found in supragranular layers. In contrast, spinous stellate neurons lacked in projections from area 19, 21a, PMLS and postero-lateral lateral suprasylvian (PLLS). In all areas, the infragranular neurons showed heterogeneous typology, but in PMLS no fusiform cells were found. Quantitative analysis of basal dendrites did not reveal significant differences in total dendritic length, terminal, or intermediate segment length among neurons in area 17 or 18, and this was related to whether they projected to contralateral areas 17–18 or PMLS. All injections produced exuberant labeling in area 17. No differences could be found between neurons in area 17 (with transient axons through the corpus callosum) and neurons near the 17/18 border (which maintain projections to the corpus callosum). In conclusion, morphology of callosally projecting neurons seems to relate more to intrinsic specificities in the cellular composition of each area than to the area of contralateral axonal projection or the fate of callosal axons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00230198
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Neurons with callosal projections in visual areas of newborn kittens: an analysis of their dendritic phenotype with respect to the fate of the callosal axon and of its target (1991)
    Springer
    Experimental brain research 86 (1991), S. 151-158 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex ; Corpus callosum ; Dendrites ; Development ; Trophic interactions ; Kitten
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Combined retrograde transport of Rhodamine-labeled latex beads and intracellular injection of Lucifer Yellow in aldehyde-fixed slices of areas 17 and 18 in kittens indicate that neurons with similar dendritic morphology send axons into the corpus callosum from the 17/18 border and from parts of area 17 destined to become acallosal. At both sites callosally projecting neurons (callosal neurons) include pyramids, spiny stellate cells and star-pyramids; two types of pyramidal neurons can be distinguished on the basis of the complexity of their apical dendrites. At both sites, the dendritic morphology of callosal neurons appears basically unaffected by the ablation at the beginning of the second postnatal week of the contralateral areas 17 and 18 to which they have sent their axon. Thus the dendritic morphology of this type of cortical neuron seems independent of retrograde signals coming from their contralateral target and may instead depend on “programs” intrinsic to the neurons and/or conditions acting locally on their cell bodies, dendrites or initial axon collaterals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231049
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Vertical organization in the visual cortex (area 17) in the cat (1974)
    Springer
    Experimental brain research 21 (1974), S. 315-336 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex (area 17) ; Cat ; Columnar organization ; Retino-cortical scatter ; Intracortical connections
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Responses of cortical cells in the cat's area 17 (central and paracentral area), recorded successively during electrode penetrations perpendicular to the surface, were averaged (PSTH). All cells recorded during one penetration were stimulated with the same stimulus, a slowly moving light or dark slit oriented optimally for the first cell recorded. Comparisons between successively recorded cells were completed by simultaneous recordings from two neurones with the same microelectrode tip. Eye movements as an error were excluded by simultaneous recording of a geniculate cell throughout a cortical penetration. 2. The centers of excitatory receptive fields (ERFs) of simultaneously or successively recorded cells during a penetration may be separated by more than 4°. The mean scatter around a column average is 0.81±0.99° in both directions. The scatter is independent of the recording depth. Whereas the optimal orientation of cells recorded during one penetration was generally similar, the optimal direction (forward and backward movement of an optimally oriented stimulus) was variable. 3. The ERF diameters as determined from the PSTH were between 〈0.5° and 7.5°. During each penetration, cells with small (up to 3.0°) and large (〉3.0°) ERFs could be discriminated. The inhibitory fields (determined with the conditioning method of Bishop, Coombs and Henry, 1971) were between 2.0 and 8.5° along both the optimal and the non-optimal orientation axis of a cell. The borders of inhibitory fields of cells collected during one penetration were also scattered though overlapping. 4. Response analysis of simultaneously and successively recorded cells with different stimuli indicated that, in spite of considerable ERF-overlap, cells with small ERFs had separate excitatory inputs and that intracortical excitatory connections between cells recorded during one penetration were improbable. 5. The ERFs of cells with large ERFs covered a field approximately corresponding to the fields of cells with small ERFs. But a convergent input from many small ERF cells to single large ERF cells was excluded because of the incompatible functional properties of both types of cells, which correspond to some extent to simple and complex cells respectively. 6. It is concluded that cells within cortical cylinders are not connected through excitatory contacts with each other and that most cells in area 17 are excited by individual excitatory geniculate or cortical inputs. Inhibitory connections seem to be the most important intracortical connections. 7. In an Appendix it is shown that anatomical and physiological data do not support significant excitatory convergence of specific geniculate afferents on cortical neurones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235750
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Postnatal shaping of callosal connections from sensory areas (1980)
    Springer
    Experimental brain research 38 (1980), S. 381-394 
    Details
    ISSN: 1432-1106
    Keywords: Corpus callosum ; Visual cortex ; Somatosensory cortex ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Horseradish peroxidase (HRP) was injected unilaterally into the first and second visual areas (VI and V2; areas 17 and 18) of 20 kittens aged between 2 and 90 days and into the second somatosensory area (S2) of 16 kittens aged between 1 and 52 days. The radial and tangential (normal and parallel to the pial surface, respectively) distributions of neurones giving origin to callosal axons (callosal neurones) were studied. In adult cats, callosal efferent zones (CZs) are defined by the distribution of callosal neurones. CZs occupy, in the visual cortices, tangentially and radially restricted parts of areas 17, 18, 19 of the lateral suprasylvian gyms and in the somatosensory cortices, parts of SI and S2. At birth, callosal neurones are distributed throughout the tangential extent of visual and somatosensory areas; they are also more widespread in depth than in the adult. During the first postnatal month, as a result of the gradual disappearence of callosal neurones from parts of the visual and somatosensory areas, the adult CZs emerge. The CZ in areas 17 and 18 undergoes a further tangential reduction during the second and third postnatal months.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237518
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The postnatal development of visual callosal connections in the absence of visual experience or of the eyes (1980)
    Springer
    Experimental brain research 39 (1980), S. 365-375 
    Details
    ISSN: 1432-1106
    Keywords: Corpus callosum ; Visual cortex ; Visual deprivation ; Enucleation ; Plasticity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Counts of callosal neurons retrogradely labeled by horseradish peroxidase (visualized using multiple substrates) were obtained in areas 17 and 18 of five kittens reared with their eyelids bilaterally sutured and of three kittens which had undergone bilateral enucleation on postnatal days 1–4. These counts were compared with those obtained in normal adult cats. The normal adult distribution of the callosal neurons results from the gradual postnatal reduction of a more widespread juvenile population. Binocular visual deprivation by lid suturing dramatically decreases the final number of callosal neurons and narrows their region of distribution (callosal zone) in areas 17 and 18. A less severe reduction in the final number of callosal neurons is caused by bilateral enucleation, which also increases the width of the callosal zone compared to that of normal cats. Thus, visual experience is necessary for the normal stabilization of juvenile callosal connections. However, since some callosal neurons form connections in the absence of vision, other influences capable of stabilizing juvenile callosal neurons also exist. These influences are probably antagonized by destabilizing influences or inhibited, when the eyes are intact.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239301
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...