Structure of human auditory cortex. II. Axon distributions and morphological correlates of speech perception

Seldon, H. Lee

doi:10.1016/0006-8993(81)90995-1

Cited by 132 publications

(61 citation statements)

References 31 publications

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“…Qualitative descriptions of different degrees of a vertical organization within the cerebral cortex have also been used by others for differentiating and characterizing cortical areas (Filimonoff, 1932;Fleischhauer and Detzer, 1975;Seldon, 1981;Eidelberg and Galaburda, 1984;Ong et al, 1990). To the best of our knowledge, this study is the first attempt to quantitatively describe different degrees of columnar organization in different cytoarchitectonically defined cortical areas.…”

Section: Discussionmentioning

confidence: 89%

Quantitative analysis of the columnar arrangement of neurons in the human cingulate cortex

Schlaug

Schleicher

Zilles

1995

J of Comparative Neurology

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The spatial organization of human cingulate (areas 24b, 23b, and 31) and pericingulate (areas 7 and 19) cortex was examined by using an image analyzer to measure characteristics of vertically oriented, translaminar columns of neurons in the cerebral cortex. Columns of 30-50 microns in diameter are hypothesized to be a general feature of cortical organization, but no quantitative analysis of different human cortical areas has been performed. Our results prove for the first time that a columnar organization was detectable in every area examined. The average width of cell columns was approximately 40 microns separated by a neuropil-rich fascicle of the same dimension. Because differences in the expression of a columnar organization were seen, the degree of columnization was subsequently expressed by a verticality index (VI) revealing specific changes in its dimension depending on the architectonic area. The VI was calculated by a linear combination of three variables derived from the measurement of cell density profiles in Nissl-stained sections at right angles to vertically oriented cell columns. Variables included the amplitude of profile peaks, the standard deviation of the width of those profile peaks, and the standard deviation of the distances between profile peaks. The index of verticality describes the deviation of a distinct area and layer from the mean degree of vertical organization of all cortical areas and layers examined. Thus, different degrees of columnar organization can be quantitatively described by the verticality index and can be used as criteria to characterize architectonic areas.

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Section: Discussionmentioning

confidence: 89%

Quantitative analysis of the columnar arrangement of neurons in the human cingulate cortex

Schlaug

Schleicher

Zilles

1995

J of Comparative Neurology

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“…These differences suggest that alterations in minicolumn organization-in autism-may have a profound impact on hemispheric specialization and functions that dependent on hemispheric specialization (such as language). In normal brain, the width of minicolumns and the distance between the columns is larger on the left than on the right [Seldon, 1981a[Seldon, , 1981b[Seldon, , 1982Buxhoeveden et al, 2001]. Seldon [1981aSeldon [ , 1981bSeldon [ , 1982 also showed that pyramidal cells in the posterior language cortex on the left contacted fewer columnar units than on the right.…”

Section: Brain Serotonin In Autistic Childrenmentioning

confidence: 98%

“…In normal brain, the width of minicolumns and the distance between the columns is larger on the left than on the right [Seldon, 1981a[Seldon, , 1981b[Seldon, , 1982Buxhoeveden et al, 2001]. Seldon [1981aSeldon [ , 1981bSeldon [ , 1982 also showed that pyramidal cells in the posterior language cortex on the left contacted fewer columnar units than on the right. In addition, there is asymmetry in the size of the pyramidal cells constituting the minicolumns, with a greater number of large pyramidal cells in the left hemisphere than in the right hemisphere [Hutsler, 2003].…”

Section: Brain Serotonin In Autistic Childrenmentioning

confidence: 98%

Serotonin in autism and pediatric epilepsies

Chugani

2004

Ment. Retard. Dev. Disabil. Res. Rev.

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Serotonergic abnormalities have been reported in both autism and epilepsy. This association may provide insights into underlying mechanisms of these disorders because serotonin plays an important neurotrophic role during brain development-and there is evidence for abnormal cortical development in both autism and some forms of epilepsy. This review explores the hypothesis that an early disturbance in the serotonin system affects cortical development and the development of thalamocortical innervation, and is a potential mechanism, common to autism and pediatric epilepsies associated with cortical dysplasia. An argument is made that cortical malformation leads to abnormalities of thalamocortical connectivity, and that serotonin plays a critical role in this process. Finally, a role for altered metabolism of the serotonin precursur, tryptophan, in both epilepsy and autism is discussed. Key Words: serotonin; autism; epilepsy; tryptophan; cortical development; kynurenine E pilepsy is more common among autistic children than in the general population; conversely, autism (or milder pervasive developmental disorders) is more common in epileptic children than in the general population. There is evidence for abnormalities of the neurotransmitter serotonin in both epilepsy and autism. The role of serotonin in brain development is briefly reviewed here and then the evidence considered for a role of an altered serotonin system in these developmental disorders. We hypothesize that serotonergic abnormalities during prenatal and early postnatal development may lead to changes in thalamocortical connectivity, which results in a predisposition for autism and epilepsy. In addition, we discuss the involvement of aberrant metabolism of tryptophan-the metabolic precursor of serotonin-as a potential mechanism for alterations in serotonin availability.

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“…Zatorre [2001] pointed out that the findings of Lié-geois-Chauvel et al [2001] could be the consequence of a more general principle underlying hemispheric specialization. Based on macro-and micro-anatomical studies, he argued that the right hemispheric superiority to process spectral information may be due to a relatively weaker myelination of nerve fibers [Penhune et al, 1996;Anderson et al, 1999], smaller layer IV pyramidal cells [Hutsler and Gazzaniga, 1996], and more narrowly spaced columns [Seldon, 1981]. All these features are characteristic of neural nets exhibiting a low degree of spatial integration, i.e.…”

Section: Hemispheric Differencesmentioning

confidence: 99%

Sensitivity of the Neuromagnetic N100m Deflection to Spectral Bandwidth: A Function of the Auditory Periphery?

Seither-Preisler

Krumbholz²,

Lütkenhöner³

2003

Audiol Neurotol

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The amplitude of the auditory evoked field (AEF) component N100m in response to tonal stimuli of varying spectral bandwidth and periodicity was compared with simulated peripheral activity patterns of the auditory nerve (AN). The AEF of ten subjects was recorded with a 37-channel axial gradiometer system (four independent measurement sessions per hemisphere). The simulated peripheral activity was characterized using measures derived from spike probabilities of the AN. Stimuli were pure tones, narrow-band harmonic complex tones (spectrum: 4–4.8 kHz), and broad-band harmonic complex tones (spectrum: 800 Hz–4.8 kHz) with periodicities of 100, 200, and 400 Hz. The intensity of all stimuli was set to 65 dB above the absolute thresholds. Both the simulated AN activity and measured cortical response amplitudes increased consistently with spectral bandwidth. This suggests that the enhanced sensitivity of the N100m amplitude to broad-band complex tones is to some extent a function of the auditory periphery.

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Structure of human auditory cortex. II. Axon distributions and morphological correlates of speech perception

Cited by 132 publications

References 31 publications

Quantitative analysis of the columnar arrangement of neurons in the human cingulate cortex

Quantitative analysis of the columnar arrangement of neurons in the human cingulate cortex

Serotonin in autism and pediatric epilepsies

Sensitivity of the Neuromagnetic N100m Deflection to Spectral Bandwidth: A Function of the Auditory Periphery?

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