摘要:

AbstractThe expanse of cerebral cortex containing corticopontine neurons was explored in rats. The retrograde tracer horseradish peroxidase (HRP) was iontophoresed into subdivisions of the pontine nuclei (PN). The densest projection was seen to originate from somatosensory and motor areas. Visual areas also provide a major contingent of corticopontine neurons, whereas auditory areas appear to have only a minor projection. Consistent labeling of cells was also seen in the granular cingulate cortex, especially in the junction region of anterior and posterior cingulate cortex. This and a sparse projection from dorsal and posterior “insular” cortex (rhinal sulcus) have not been described in detail in previous stud

ISSN:0092-7317    

DOI:10.1002/cne.902080302

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe projection from various cortical areas to the pontine nuclei (PN) of rats was investigated with anterograde tracing methods. As a general topological rule, a medial to lateral succession of the PN projection fields from the motor, somatosensory, and visual cortices was observed. Apart from the main “private” projections, each cortical area was found to send fibers also to disjunctive “extra‐projection” territories which receive convergent inputs from two or more cortical areas. The sensorimotor and visual cortices provide the bulk of corticofugal fibers, but contributions from the following association areas were noted: frontal cortex, (dependent of the thalamic mediodorsal nucleus), rhinal sulcus region, and cingula

ISSN:0092-7317    

DOI:10.1002/cne.902080303

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractAnterograde and retrograde tracing techniques were employed to delineate the organization of a visual cortical input to the deep layers of the hamster's superior colliculus which may be mediated by links in the striatum and substantia nigra.Autoradiographic experiments showed that areas 17, 18a, and the cortex medial to area 17 (areas 18b and 29) all projected to the dorsocaudal part of the ipsilateral striatum. This projection was organized so that the rostrocaudal axis of the visual cortex was represented along the anteroposterior axis of the striatum. Large posterior neocortical injections which included all of these areas also revealed a weak, crossed corticostriatal pathway. Such injections also demonstrated clear discontinuities in the terminal distribution of the visual corticostriatal projection, similar to those which have been noted after injections of tracers into the motor and premotor cortices.Retrograde tracing experiments showed that the cells of origin of the visual cortical projections to the striatum were medium‐sized pyramidal neurons located primarily in the upper portion of lamina V.Anterograde transport of [3H]‐leucine and HRP showed that the portion of the striatum heavily innervated by the visual cortex projected to the part of substantia nigra, pars reticulata immediately adjacent to the cerebral peduncle. Injections in the rostral striatum labeled more medial portions of this nucleus. The cells of origin of the striatonigral pathway measured between 13 and 20 μm in diameter and they were located primarily in the dorsal and lateral parts of the striatum.Anterograde tracing after substantia nigra, pars reticulata injections revealed a projection to both superior colliculi. The uncrossed pathway terminated primarily as a series of patches throughout the mediolateral and rostrocaudal extents of the lower stratum griseum intermediale and stratum album intermedium. Labeling was also visible in the lateral portion of the stratum griseum profundum. The crossed nigrotectal pathway terminated primarily in the rostrolateral stratum griseum profundum. The cells of origin of the nigrocollicular pathway were fusiform or multipolar cells and were located primarily adjacent to the cerebral peduncle throughout the rostral half of the substantia nigra, pars reticu

ISSN:0092-7317    

DOI:10.1002/cne.902080304

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractRepetitive left mystacial vibrissae movements were produced by electrical stimulation of right motor cortex (MI) with a bipolar electrode in the alert, unanesthetized rat. Regional increases of (14C) 2‐deoxyglucose (2DG) uptake were mapped autoradiographically during these left vibrissae movements. Uptake of 2DG increased in a 2–4‐mm‐diameter area about the stimulating electrode in right MI and in a smaller region in left MI cortex. Columnar increases of 2DG uptake occurred bilaterally in somatosensory cortex in the face region of somatosensory cortex (SI). Bilateral increases of 2DG uptake occurred subcortically in dorsolateral caudate‐putamen (CP) and subthalamic nucleus. Primarily right‐sided increases of 2DG uptake occurred in other basal ganglia structures including dorsal globus pallidus (GP), posterior entopeduncular nucleus (EPN), ventrolateral substantia nigra pars reticulata (SNr), and anterolateral substantia nigra pars compacta (SNc). Uptake of 2DG increased on the right side of the following thalamic regions: much of the ventrolateral (VL) nucleus, particularly dorsally; the anterodorsal reticular nucleus; dorsolateral posteromedial (POm) nucleus; the ventromedial nucleus; and dorsolateral parafasicular nucleus. The anterior and ventral posterior portions of VL were not activated. Caudal to thalamus right‐sided 2DG uptake increased in the medial, ventral, and lateral pontine nuclei, deep layers of superior colliculus, lateral deep mesencephalic nucleus (DMN), and nucleus cuneiformis (NCU). Uptake of 2DG increased in right rostral parvocellular red nucleus in a few animals. Discrete portions of the right internal capsule and right medial pyramidal tract increased 2DG uptake during MI stimulation.Uptake of 2DG increased on the left side of the brain during right MI stimulation in the left lateral nucleus (NL) of cerebellum and in several discrete regions of left cerebellar hemisphere granule cells including anterior paravermis, lobulus simplex, crus II, and the paramedian lobule. Uptake of 2DG increased in left nucleus of the spinal tract of the trigeminal nerve (ntV) ventrally in subnuclei interpolaris and oralis. Left lateral portions of the facial nucleus were activated in a few animals. The lateral portions of the facial nucleus are known to project to vibrissae musculature.All of the above structures may be involved in the motor‐sensory processing responsible for vibrissae movements. Regions not previously suggested to play a major role in vibrissae movements include DMN and NCU. Though NCU has been called the “locomotor center” it may play a role in facial movements as well. Polysynaptic activation of GP, EPN, NL, and cerebellar hemisphere occurred since no connections between MI and these regions exist. A pathway from ntV to POm to MI and SI is suggested to provide proprioceptive input to motor‐sensory cortex from the moving vibrissae since neither the principal trigeminal sensory nucleus nor the ventrobasal nucleus of thalamus increased 2DG uptake

ISSN:0092-7317    

DOI:10.1002/cne.902080305

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractA perfused, isolated retina‐eyecup preparation of the rabbit was utilized to correlate the physiology and morphology of horizontal cells. Neurons were physiologically characterized by intracellular recording techniques and subsequently stained with intracellular iontophoretically injected horseradish peroxidase for morphological identification. Three types of rabbit horizontal cell recordings have been differentiated, based on variations in response waveform, amplitude‐intensity properties, and area summation characteristics. These three types have been unequivocally associated with the axonless A‐type horizontal cells and the somatic and axon terminal endings (each displaying its own distinct physiology) of B‐type horizontal cells first described in studies using Golgi‐impregnation techniques (Fisher and Boycott, 1974). In addition, the sizes of A‐type horizontal cells were found to be directly related to their retinal eccentricities from the optic disk. However, a unique subclass of A‐type cells has been discovered (elongated or Ae type) which displayed the largest dendritic field of any cells studied here, yet had the smallest eccentricities—within 1.4 mm of the optic disk. Moreover, elongated A‐type cells exhibited long asymmetrical dendritic fields which were oriented parallel with the visual streak. The unique asymmetry and orientation of these cells suggests that they may have orientation‐biased receptive field properties. Physiological evidence for an orientation‐biased horizontal cell is presented in s

ISSN:0092-7317    

DOI:10.1002/cne.902080306

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

摘要:

AbstractSubstance P‐like immunoreactivity was examined in theLimuluslateral eye and protocerebrum by the unlabeled antibody peroxidase‐antiperoxidase method. Small‐diameter immunoreactive fibers innervate the corneal epidermis of the lateral eye and appear to be part of a generalized epidermal innervation. No immunoreactive neurons or fibers were found in the ventral, median, or lateral optic nerves nor in the lamina or chiasma. The optic medulla contains neurons with immunoreactive perinuclear caps in the ganglion cell layer and fibers of undetermined origin in the posterolateral regions of the neuropil. The central body contains many immunoreactive fibers in its neuropil, some or all of which arise from neurons adjacent to its anteromedial tips. Immunoreactive neurons within the curve of the central body give rise to processes which join the central neuropil of the protocerebrum. The immunoreactive innervation of the corpora pedunculata includes processes which terminate among Kenyon cell somata, and processes in the peduncular neuropil, all of which arise from a bilateral cluster of neurons along the midline. Attempts to investigate the source of the immunoreactive fibers using cobalt impregnation of the severed circumesophageal connective have revealed two additional innervations of the corpora pedunculata, one from raphe neurons along the midline and one from lateral portions of the midline ganglion adjacent to but separate from that portion containing the immunoreactive neurons. The results demonstrate that immunocytochemical methods are another powerful tool for the study of neuronal pathways in inverteb

ISSN:0092-7317    

DOI:10.1002/cne.902080307

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.902080301

出版商:Alan R. Liss, Inc.    

年代:1982

数据来源: WILEY