摘要:

Squirrel monkeys were filmed in the act of prehending objects of various sizes, shapes, and states of motion. Subsequent three-dimensional analyses indicated that general aspects of prehension do not vary grossly across individuals nor as a function of the object to be prehended, at least at the level of measurement used in these studies. The monkeys exhibited only whole-hand control, even with small or moving objects. However, in comparison with stationary objects, moving objects did elicit variations of arm and hand positions, and were associated with higher frequencies of blinking than nonmoving objects: Some stationary objects also elicited subtle adjustments of movement and form. Sex differences were found in several aspects of prehensive movement and passive joint mobility, but the significance of these findings is not yet clear.

ISSN:0006-8977    

DOI:10.1159/000121499

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Rubral neurons innervating the spinal cord, the lateral brainstem and the inferior olivary nucleus have been identified in the North American opossum by the retrograde transport of horseradish peroxidase and fluorescent markers. Neurons which project to the spinal cord are found mainly in caudal and rostroventral parts of the red nucleus. In contrast, rubral neurons which innervate the facial nucleus and lateral areas of the medulla are most numerous rostrodorsally. There is overlap in the location of rubral neurons which project to the spinal cord and lateral brainstem, however and; double-labelling techniques show that some rubral neurons provide collaterals to both areas. Neurons which innervate the inferior olive are located primarily in rostromedial portions of the red nucleus with some overlap with those innervating the spinal cord. Few rubral neurons provide collaterals to both the spinal cord and inferior olive.

ISSN:0006-8977    

DOI:10.1159/000121490

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

Afferents from limbic system-related structures (aside from the cingulate and retrosplenial cortex) to medial and lateral regions of the bush baby's frontal cortex were investigated by means of the somatopetal transport of horseradish peroxidase. The frontopolar region received afferents from the subicular cortex, the lateral nucleus of the amygdala, from hypothalamic nuclei ventral tegmental area and other brain stem nuclei. Injections of horseradish peroxidase into other frontal regions usually resulted in labeled cellsin brain stem nuclei and in the hypothalamus, but not in telencephalic regions; only the large injection into the posterior part of the frontal cortex was followed by labeled amygdaloid neurons. From these results it is concluded that a small number of limbic system-related telencephalic areas projects to the frontal cortex and that a somewhat larger number of diencephalic and brain stem nuclei reaches this part of the cortex.

ISSN:0006-8977    

DOI:10.1159/000121491

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

This article attempts to develop an empirical foundation for the notion of 'cell type', and to use this notion to clarify the issues involved in the classification, pathways, and trans-species comparisons of retinal ganglion cells.

ISSN:0006-8977    

DOI:10.1159/000121492

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

This article attempts to develop an empirical foundation for the notion of 'cell type', and to use this notion to clarify the issues involved in the classification, pathways, and trans-species comparisons of retinal ganglion cells.

ISSN:0006-8977    

DOI:10.1159/000315993

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

This article attempts to develop an empirical foundation for the notion of 'cell type', and to use this notion to clarify the issues involved in the classification, pathways, and trans-species comparisons of retinal ganglion cells.

ISSN:0006-8977    

DOI:10.1159/000121493

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

A morphometric analysis of the corticospinal tract's relation to digital dexterity was performed on 21 species theoretically related to man's ancestral lineage. The results indicate that the Primate line is not unique among mammals with respect to the cortical control of digital dexterity. A comparative analysis suggests that two changes took place early in Primate evolution: a reduction in functional distance (i.e. number of synapses) between neocortex and spinal motor neurons innervating the digits, and an extension of direct neocortical influence beyond the cervical segments of the spinal cord. A further change progressed throughout Primate evolution, from the mid-Eocene to the present, in which the overall size of the corticospinal tract increased steadily as though consolidating the cortical influence over body musculature, especially that of the digits.

ISSN:0006-8977    

DOI:10.1159/000121494

出版商:S. Karger AG    

年代:1983

数据来源: Karger

摘要:

To assess the locations and densities of cells in the dorsal medulla giving rise to ipsilateral versus contralateral projections to the mechanosensory regions of cerebellar cortex in the anterior lobe and paramedian lobule, these cortical regions were injected unilaterally with horseradish peroxidase in each of 5 raccoons. To show injection sites and retrogradely labelled cells in the medulla, sections through the medulla and the cerebellum, in at least two different planes for each, were reacted with tetramethylbenzidine; alternate sections were reacted with cobalt-enhanced diaminobenzidine. Labelled were 60–80% of cells in the ipsilateral and 15–25% of cells in the contralateral external cuneate nuclei, as well as 25–50% of cells in the ipsilateral and the contralateral cell groups f and x near the descending vestibular nucleus.Substantial contralateral, as well as ipsilateral cerebellar projections from external cuneate nuclei and cell group x may be related to development of forelimb dexterity in raccoons, since these nuclei mediate forelimb muscular sensibility. The numerical complementarity of ipsilaterally versus contralaterally projecting cells suggests that they represent two separate populations.

ISSN:0006-8977    

DOI:10.1159/000121495

出版商:S. Karger AG    

年代:1983

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000121496

出版商:S. Karger AG    

年代:1983

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000121497

出版商:S. Karger AG    

年代:1983

数据来源: Karger