摘要:

AbstractDirect projections from the anterior part of the orbital gyrus and its immediate vicinity to telencephalic and diencephalic structures in the cat were investigated by means of the Nauta and Marchi methods.Association fibers were observed to project to the ipsilateral coronal gyrus, the anterior part of the insular cortex, and the lateral part of the pericruciate gyrus. Degenerated fibers originating at the site of the lesion were traced to the callosal body, and from there chiefly to the contralateral putamen and the contralateral orbital and coronal gyri. Projection fibers to the telencephalic nuclei were found to terminate in the head of the caudate nucleus, the putamen, claustrum, and anterior amygdaloid area. Degenerated fibers in the external capsule were traced to the prepyriform area and the lateral part of the olfactory tubercle. Some of these components were observed to join the medial forebrain bundle and could be followed to the lateral preoptic area. Orbitothalamic fibers were traced through the anterior limb of the internal capsule and the internal medullary lamina. These fibers were found to terminate in the rostroventral part of the nucleus reticularis and ventralis anterior, and in the rostral parts of the intralaminal nuclei.

ISSN:0092-7317    

DOI:10.1002/cne.901360202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractThe supraoptic nucleus in man extends throughout the greater length of the hypothalamus and most of it is retrochiasmatic in location. It contains an average of 75,500 neurons, of which about two‐thirds are in its dorsolateral portion (SON‐dl) and one‐third in its combined dorsomedial and ventromedial portions. The average density of neurons in SON‐dl is 15,300 per mm3and, unlike neuron frequency, is remarkably constant from specimen to specimen. The paraventricular nucleus has an average of 55,500 magnocellular neurons.In patients surviving one year or longer after hypophysectomy, there is retrograde loss of over 80% of neurons in both the supraoptic and paraventricular nuclei. Neuron loss occurs uniformly thrughout the length of each nucleus. Density decrease in SON‐dl is almost exactly proportional to decrease in neuron frequency.It is concluded from these observations that most of the neurons throughout the entire extent of both the supraoptic and paraventricular nuclei in man project to the posterior lobe of the neurohypophysis and that there are over 200,000 fibers in the hypophys

ISSN:0092-7317    

DOI:10.1002/cne.901360203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractThe arrangement of the trigeminal nerve or its primordium was studied in 27 baboon embryos and fetuses 2.5–63.0 mm (crown‐rump length), 24–64 days insemination age. The head region of seven representative specimens was reconstructed graphically or with wax. The entire extramedullary part of the nerve, including the related parasympathetic ganglia, was traced microscopically in serial sections stained with either hematoxylin and eosin or protargol‐S and eosin.The crest is first apparent in five somite embryos (24 days) and becomes more prominent and extends farther ventrally by eight somites (25 days). Lateral and ventral to the crest the ectoderm shows a slight, gradual thickening but not as a distinct placode. At 11–19 somites (25–27 days) the primordium is a column of cells that becomes loosely arranged as it terminates in the first arch. By 21–22 somites (28 days) the enlarged primordium has the three divisions with the mandibular being most prominent and closely applied to ectoderm near the first groove. Between 26 and 36 somites (29–30 days) the trigemial ganglion and motor root become apparent. The distal part of each division is eosinophilic and fibrous. Branches from each division begin to form as sprays of fibers by 6.9–9.0 mm (32–33 days) and the primordia of the four related parasympathetic ganglia become evident. Many of the definitive branches and their communications with other nerves are present at 11.6–16.5 mm (36–40 days). Most of the branches and many communications with the facial nerve are established by 18.3–36.0 mm (45–54 days). All of the named branches, including the meningeal branches, are

ISSN:0092-7317    

DOI:10.1002/cne.901360204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractProjections of the feline inferior colliculus were studied using the Nauta‐Laidlaw method to demonstrate degenerating axons. A subtentorial stereotaxic approach was used to avoid corticofugal degeneration. Direct connections from the inferior colliculus to the anterior midline cerebellar cortex were observed. There is a topographical relationship of fibers of the brachium of the inferior colliculus and parabrachial region to the superior colliculus. A definite projection to the superior colliculi including a pathway through its commissure was found from the parabrachial region. A projection exists from the inferior colliculus to the dorsolateral portion of the central gray as far as the pretectum. There is a projection along the medial portion of the superior colliculus to the pretectum. Projections to the midbrain reticular formation, central gray and superior colliculi were substantial. Thalamic projections include a distribution of fibers to the magnocellular and rostral portion of the principal divisions of the medial geniculate body and to the lateral posterior thalamic nucleus. The rostral connections of the inferior colliculus with areas other than the medial geniculate body indicate that it may function in roles in addition to that of a mass somatomotor reflex center. Possible roles of the inferior colliculus in attention, habituation, and integration of corticovisual and auditory impulses are suggeste

ISSN:0092-7317    

DOI:10.1002/cne.901360205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractThe distribution of degenerating fibers within the intralaminar nuclei was studied following lesions of the cerebral neocortex inMacaca mulatta, M. nemestrima, M. irus, Cercopithecus aethiops sabaeusandSaimiri sciureus.Degenerating fibers were revealed by the Nauta silver method.The cortex rostral to the central sulcus appeared to be the principal source of cortical fibers projecting to intralaminar nuclei. Very few degenerating fibers were observed in intralaminar nuclei following parietal, temporal or occipital lobe lesions. Efferent fibers of the prefrontal lobe terminated predominantly in paracentral and parafascicular nuclei. Premotor cortex projected mainly to central lateral and parafascicular nuclei. Motor cortex projected to central lateral and centromedian nuclei. The projection from motor cortex to the ventrolateral centromedian nucleus was topographically distributed, with fibers from leg area terminating lateral to those from arm area.

ISSN:0092-7317    

DOI:10.1002/cne.901360206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractIn the optic tectum Cajal's method II for neurofibrils reveals two major fiber systems in which the fibers are oriented perpendicular to one another. Theouter fiber system, composed of seven laminae, lies in the superficial zone with its fibers oriented in the anteroventral to posterodorsal direction; Golgi preparations show that optic tract fibers enter the outer system laminae at the tectal margin, run within single laminae, and end in arborizations that are elongated in the dominant fiber direction. Theintermediate fiber systemis composed of bundles of fibers in lamina 7 of Ramón and the superficial zone; its fibers are oriented in the anterodorsal to posteroventral direction. A thirddeep fiber system, forms fibrous laminae in the region between lamina 7 and the ependyma.In Golgi impregnations the deep cells are of two major classes:pyramidal cellswith relatively narrow dendritic arbors in the superficial zone andcandelabra cellswith broad arbors. Many pyamidal cell dendrites have lamellar branching patterns such that terminal bushes occur within one or another of the outer system laminae. Themultipolar cellswithin lamina 6 and lamina 7 of Ramón send large, unbranched axons directly into the deep medullary lamina and appear to be the major efferent neurons. Near the pia the perikarya ofsuperficial granule cellsgive rise to single processes that branch repeatedly within the superficial zon

ISSN:0092-7317    

DOI:10.1002/cne.901360207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractA nucleus was found in the dorsolateral funiculus of the spinal cord of the guinea‐pig. The nucleus extended from upper cervical to lumbar segments of the cord and was similar in appearance to that previously described in the rat. The nucleus also extended into lumbar segments of the spinal cord in both the rabbit and the ferret although in these species there were not as many cells in the nucleus in thoracic and lumbar segments of the cord as in the guinea‐pig. In the cat, the nucleus was confined to the upper two or three cervical segments of the spinal c

ISSN:0092-7317    

DOI:10.1002/cne.901360208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

摘要:

AbstractThe rate of growth of the various regions of the spinal cord and the vertebral column of the albino mouse aged, 1, 10, 20, 30 and 120 days was studied. It was found that:(1)There is more rapid growth in the length of the vertebral column than that of the spinal cord. The lower regions of the vertebral column grow more rapidly than the upper regions but the reverse was found in the spinal cord resulting in regression of the spinal cord. The cord ends at one day opposite the fifth sacral vertebra and then receded to the fifth lumbar vertebra till 120 days.(2)The white matter has a more rapid rate of growth in volume than the gray matter. So the process of myelination and the growth of the fibers in diameter exceed the rate of growth of the neurons and their dendrites.(3)The packing density of the neurons is nearly the same in all regions of the cord with the exception of the cervical region which showed less packing density due to more branching of their dendrites.(4)The total number of neurons at each region is fixed from birth till maturity. The thoracic region contains the highest number of neurons followed by the cervical then the lumbar and the least number is in the sacral region.

ISSN:0092-7317    

DOI:10.1002/cne.901360209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.901360201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1969

数据来源: WILEY