Terminal arbors of axons projecting to the somatosensory cortex of the adult rat. II. The altered morphology of thalamocortical afferents following neonatal infraorbital nerve cut

Jensen, Karl F.; Killackey, Herbert P.

doi:10.1523/jneurosci.07-11-03544.1987

Cited by 98 publications

(62 citation statements)

References 21 publications

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“…These observations are in agreement with studies showing that neonatal infraorbital nerve cut results in larger thalamocortical arbors in somatosensory cortex (Jensen and Killackey, 1987). Also as in the somatosensory system (Catalano et al, 1995), the effects of neonatal enucleation on callosal axons were rapid, indicating that deafferentation in both the visual and somatosensory systems acts by altering the initial elaboration of arbors in the neocortex rather than by inhibiting a later-occurring remodeling process.…”

Section: Discussionsupporting

confidence: 91%

Topography and axon arbor architecture in the visual callosal pathway: effects of deafferentation and blockade of TV-methyl-D-aspartate receptors

et al. 2008

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Visual callosal fibers link cortical loci in opposite hemispheres that represent the same visual field but whose locations are not mirror-symmetric with respect to the brain midline. Presence of the eyes from postnatal day 4 (P4) to P6 is required for this map to be specified. We tested the hypothesis that specification of the callosal map requires the activation of N-methyl-D-aspartate receptors (NMDARs). Our results show that blockade of NMDARs with MK-801 during this critical period did not induce obvious abnormalities in callosal connectivity patterns, suggesting that retinal influences do not operate through NMDAR-mediated processes to specify normal callosal topography. In contrast, we found that interfering with NMDAR function either through MK801-induced blockade of NMDARs starting at P6 or neonatal enucleation significantly increases the length of axon branches and total length of arbors, without major effects on the number of branch tips. Our results further suggest that NMDARs act by altering the initial elaboration of arbors rather than by inhibiting a later-occurring remodeling process. Since the callosal map is present by P6, just as axonal branches of simple architecture grow into gray matter, we suggest that regulation of arbor development by NMDAR-mediated processes is important for maintaining the precision of this map.

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Section: Discussionsupporting

confidence: 91%

Topography and axon arbor architecture in the visual callosal pathway: effects of deafferentation and blockade of TV-methyl-D-aspartate receptors

et al. 2008

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“…In the rat somatosensory system, early peripheral and more central damage has a profound effect on neuronal organization at succeeding levels of the neural axis up to and including primary somatosensory cortex (1)(2)(3)(4)(5). Similar effects have also been reported in the visual system (for review, see refs.…”

mentioning

confidence: 54%

Callosal projections in rat somatosensory cortex are altered by early removal of afferent input.

Koralek

Killackey

1990

Proc. Natl. Acad. Sci. U.S.A.

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During the first postnatal week, the distribu.tion of callosal projection neurons in the rat somatosensory cortex changes from a uniform to a discontinuous pattern. To determine if this change is influenced by afferent inputs to the somatosensory cortex, the effect of both early unilateral infraorbital nerve section and unilateral removal of the dorsal thalamus on the distribution of callosal projections in rat somatosensory cortex was examined. One month after either of the above manipulations at birth, the tangential distribution of callosal projections in the somatosensory cortex was examined using the combined retrograde and anterograde transport of horseradish peroxidase. Both manipulations alter the distribution of callosal projection neurons and terminations in the somatosensory cortex. After infraorbital nerve section, the distribution of callosal projections is altered in the contralateral primary somatosensory cortex. The abnormalities observed are consistent with the altered distribution of thalamocortical projections. In addition, consistent abnormalities were observed in the pattern of callosal projections of the second somatosensory area of both hemispheres. Most notably, they are absent in a portion of the region that contains the representation of the mystacial vibrissae and sinus hairs in this area. Thalamic ablation resulted in highly aberrant patterns of callosal projections in the somatosensory cortex on the operated side, where abnormal bands and clusters of callosal projections were observed in apparently random locations. These results are interpreted as evidence that both peripheral and central inputs influence the maturational changes in the distribution of callosal projection neurons.In the rat somatosensory system, early peripheral and more central damage has a profound effect on neuronal organization at succeeding levels of the neural axis up to and including primary somatosensory cortex (1-5). Similar effects have also been reported in the visual system (for review, see refs. 6 and 7) but in this case an additional effect of early damage on the distribution of interhemispheric projections that interconnect cortical visual areas by way of the corpus callosum has also been reported (8-12). The one study (13) MATERIALS AND METHODS Thirteen litters of Sprague-Dawley or of Long-Evans rats were used in this study. All neonatal surgery was performed under cryogenic anesthesia, after which rats were revived on a heating pad and returned to their dams. Rats from 4 litters were subjected to unilateral section of the infraorbital nerve on the day of birth. Rats from 7 litters had their dorsal thalami removed unilaterally by aspiration through a small-diameter glass pipette that was inserted into the cranium from a posterior approach. Rats from 2 additional litters were used as age-matched controls. The pattern of callosal projections as determined by the combined retrograde and anterograde transport of horseradish peroxidase and patterns of staining for succinic dehydrogenase of all ra...

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“…Tactile information from individual whisker deflections is sent as a topographically organized map of the whisker pad on the face from thalamic barreloids to somatosensory barrel cortex (Woolsey and Van der Loos 1970). Furthermore, studies have demonstrated that not only can the thalamus undergo plastic changes (Jensen and Killackey 1987;Catalano et al 1995;Krupa et al 1999) but thalamic plasticity may be regulated by feedback projections from somatosensory cortex (Krupa et al 1999). This required somatosensory-thalamic feedback for induction of thalamic plasticity (Krupa et al 1999) could explain why thalamic involvement alone was insufficient to mediate learning in the acquisition lesion group.…”

Section: Discussionmentioning

confidence: 99%

Cortical barrel lesions impair whisker-CS trace eyeblink conditioning

Galvez¹,

Weible²,

Disterhoft³

2007

Learn. Mem.

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Whisker deflection is an effective conditioned stimulus (CS) for trace eyeblink conditioning that has been shown to induce a learning-specific expansion of whisker-related cortical barrels, suggesting that memory storage for an aspect of the trace association resides in barrel cortex. To examine the role of the barrel cortex in acquisition and retrieval of trace eyeblink associations, the barrel cortex was lesioned either prior to (acquisition group) or following (retention group) trace conditioning. The acquisition lesion group was unable to acquire the trace conditioned response, suggesting that the whisker barrel cortex is vital for learning trace eyeblink conditioning with whisker deflection as the CS. The retention lesion group exhibited a significant reduction in expression of the previously acquired conditioned response, suggesting that an aspect of the trace association may reside in barrel cortex. These results demonstrate that the barrel cortex is important for both acquisition and retention of whisker trace eyeblink conditioning. Furthermore, these results, along with prior anatomical whisker barrel analyses suggest that the barrel cortex is a site for long-term storage of whisker trace eyeblink associations.

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Terminal arbors of axons projecting to the somatosensory cortex of the adult rat. II. The altered morphology of thalamocortical afferents following neonatal infraorbital nerve cut

Cited by 98 publications

References 21 publications

Topography and axon arbor architecture in the visual callosal pathway: effects of deafferentation and blockade of TV-methyl-D-aspartate receptors

Topography and axon arbor architecture in the visual callosal pathway: effects of deafferentation and blockade of TV-methyl-D-aspartate receptors

Callosal projections in rat somatosensory cortex are altered by early removal of afferent input.

Cortical barrel lesions impair whisker-CS trace eyeblink conditioning

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