摘要:

AbstractThis paper gives an account of the cytoarchitectonic characteristics that make it possible to delineate, from as early as day 6, different subareas of the prefrontal cortex of the rat. Three phases can be distinguished during postnatal development. The first phase (from day 1 until day 18) is dominated by differentiation of the neurons within the cortical plate and by the formation of the cortical layers. At day 1, regional differences are observed in the cytoarchitecture of the cortical plate which correspond to the future subareas of the prefrontal cortex. The formation of layer IV occurs in the dorsolateral cortex around day 6, and from this age the agranular prefrontal cortex is well demarcated from the other parts of the frontal cortex. Between day 6 and day 10, the cortical plate has disappeared and all cortical layers can be recognized in the prefrontal cortex. Differentiation of the cells within the cortical layers changes the cytoarchitectonic character of the layers through day 18. During the second phase (from day 18 until day 30) little change occurs in the cytoarchitectonic characteristics of the prefrontal subareas. During the third phase (from day 30 until day 90) the delineation of the cortical layers becomes less clear in Nissl‐stained sections, and the individual cytoarchitectonic variance increases. On the basis of cytoarchitectonic criteria it can be concluded that the orbital prefrontal cortex develops earlier than does the medial prefrontal corte

ISSN:0092-7317    

DOI:10.1002/cne.902410302

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe medial and orbital parts of the prefrontal cortex (PFC) increase in volume during the first weeks of postnatal life. At the end of this period, however, the volumes of both parts of the PFC reach a significantly higher value than in adulthood. Subsequently the volumes decrease until the adult volume is attained. The three subareas of the medial PFC (i.e., the medial precentral area, the dorsal anterior cingulate, and the prelimbic area) reach a maximum volume around day 24, while the two orbital PFC subareas (i.e., the dorsal and ventral agranular insular areas) attain their maximum value around day 30. The differences found in the growth pattern of the five PFC subareas, which are innervated by specific subnuclei of the mediodorsal nucleus of the thalamus, suggest a role of these subnuclei in the PFC development.

ISSN:0092-7317    

DOI:10.1002/cne.902410303

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe central nucleus of the amygdala (CNA) and the parabrachial nucleus of the pons (PBN) are included within a group of brain nuclei involved in autonomic responses. Previous studies have shown that the CNA sends a considerable projection to the PBN and that both nuclei contain neurons immunoreactive to many different peptides. In the present study, we used the combined retrograde fluorescence‐immunofluorescence method to determine whether the CNA projection to the PBN contains any of the following neuropeptides: corticotropin–releasing factor (CRF), neurotensin (NT), somatostatin (SS), and enkephalin (ENK). Following injections of fluorescent dye into the PBN, neurons within both lateral and medial subdivisions of the CNA were retrogradely labeled. A significant percentage of CRF (54–66%)–, NT (40–53%)–, and SS (31–50%)‐immunoreactive neurons were retrogradely labeled, predominantly within the lateral CNA. Enkephalin‐immunoreactive neurons were never retrogradely labeled, although they were often found adjacent to retrogradely labeled neurons. Our results show that the lateral CNA is a major source of CRF, NT, and SS terminals within the PBN. Neurons in the medial CNA also provide a significant contribution to the CNA‐PBN pathway, but their chemical nature remains to be determined. We conclude that CRF, NT, and SS are important putative neurotransmitters in the CNA's regulation of PBN function. This CNA‐PBN peptidergic pathway may participate in stress‐related cardiovascular an

ISSN:0092-7317    

DOI:10.1002/cne.902410304

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

年代:1985

数据来源: WILEY

摘要:

AbstractAscending projections from the midbrain central gray (CG) and from the region lateral to it were traced in the rat using tritiated amino acid autoradiography. Leucine or a cocktail of amino acids (leucine, proline, lysine, histidine, and tyrosine) were used as tracers.In addition to projections within the midbrain, ascending fibers follow three trajectories. The ventral projection passes through the ventral tegmental region of Tsai and the medial forebrain bundle to reach the hypothalamus, preoptic area, caudoputamen, substantia innominata, stria terminalis, and amygdala. There are labeled fibers in the diagonal bands of Broca and medial septum, and terminal labeling in the lateral septum, nucleus accumbens, olfactory tubercle, and frontal cortex. The dorsal periventricular projection terminates in the midline and intralaminar thalamic nuclei. The ventral periventricular projection follows the ventral component of the third ventricle into the hypothalamus, passing primarily through the dorsal hypothalamic area and labeling the rostral hypothalamus and preoptic area.Projections from the region lateral to the CG are similar, but exhibit stronger proximal, and weaker distal, projections. Rostral levels of the CG send heavier projections to the fields of Forel and the zona incerta, but fewer fibers through the supraoptic decussation, than do caudal levels.Ascending projections from the CG are both strong and widespread. Strong projections to the limbic system and the intralaminar thalamic nuclei provide an anatomical substrate for CG involvement in nociception and affective responses.

ISSN:0092-7317    

DOI:10.1002/cne.902410305

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

年代:1985

数据来源: WILEY

摘要:

AbstractBow‐shaped particle arrays on the P‐faces of the photoreceptor terminals R1–R6 in the lamina ganglionaris of the house fly represent the presynaptic sites of chemically mediated multiple‐contact synapses (Shaw and Stowe, '82, Saint Marie and Carlson, '82). A particle array consists of two polar patches of regularly arranged particles and a central patch of irregularly arranged ones. Corresponding to these P‐face arrays, the receptor E‐faces have lattices of pits opposite the polar patches, and pits and some particles at the center. The presynaptic particle array corresponds in its dimensions to the electron‐dense bar found in thin sections. The center‐to‐center spacing of the regularly arranged particles agrees with the spacing of striations found in the bar overlying the two polar elements of the postsynaptic tetrad. The elements in the two medial postsynaptic positions are hyperpolarizing monopolar cells Ll and L2, which show a strip of P‐face particles within an otherwise bare postsynaptic membrane enclosed by a ridge, and a bare Eface. Comparison with other invertebrate synapses reveals two types of organization of postsynaptic membranes. IMPs fracture with the postsynaptic P‐face in GABAergic and/or inhibitory synapses and with the E‐face in glutaminergic and/or excitatory synapses; the fly photoreceptor synapse thus fits

ISSN:0092-7317    

DOI:10.1002/cne.902410306

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

年代:1985

数据来源: WILEY

摘要:

AbstractAn analysis of vasoactive intestinal polypeptide immunoreactivity (VIP‐IR) and substance P‐IR in the cat spinal cord has revealed marked differences in the distribution of the two peptides. While substance P‐IR was located at all levels of the cord, VIP‐IR was most prominent in the sacral segments in Lissauer's tract and lamina I on the lateral edge of the dorsal horn. VIP‐IR was also present in the sacral cord in (1) laminae V, VII, and X, (2) a thin band on the medial side of the dorsal horn, (3) the dorsal commissure, (4) the lateral band of the sacral parasympathetic ucleus, and (5) in a few animals in Onuf's nucleus. In other segments of the spinal cord VIP‐IR was much less prominent but was present in Lissauer's tract and laminae I, II, and X. Substance P‐IR was more uniformly distributed at all segmental levels in laminae I–III, V, VII, and X and in the dorsal commissure.In ventrolateral lamina I of the sacral spinal cord both VIP‐IR and substance P‐IR exhibited a distinctive periodic pattern in te rostrocaudal axis. The peptides were associated with bundles of dorsoventrally oriented axons and varicosities spaced at approximately 210‐μm intervals center to center along the length of the spinal cord. The bundles in lamina I continued into lamina V where they further divided into smaller bundles that extended medially through laminae V and VII. The most prominent bundles of VIP axons passed ventrally from lateral laminae V and VII to enter lamina X and the ventral part of te dorsal gray commissure. On the other hand the maority of substance P axons in lamina V turned dorsally to join wth axons on the medial side of the dorsal horn and to pass into the dorsal part of the dorsal gray commissure. Rostrocaudal VIP axons were present not only in Lissauer's tract but also in dorsolateral lamina I, in the lateral funiculus and in the ependymal cell layer of the central canal.Following unilateral transectionofthe sacral dorsal roots (2 weeks–22 months) the density of VIP axons and terminals was markedly reduced in ipsilateral Lissauer's trat and lateral laminae I and V; however, no change was detected in lamina X. Sacral deafferentation reduced substance P‐IR in the dorsal gray commissure and in lateral laminae I and V.It is concluded that VIP‐IR and substance P‐IR are present at all levels of the cat spinal cord, but that VIP‐IR is most prominent in sacral afferent pathways. The distribution of VIP‐IR in spinal cord was very similar to the central projections of sacral visceral afferents. These findings are consistent with data from other experiments indicating that VIP may be a transmi

ISSN:0092-7317    

DOI:10.1002/cne.902410307

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

年代:1985

数据来源: WILEY

摘要:

AbstractCerebral cortical regions which send projection fibers to the reticular regions around the trigeminal motor nucleus were identified in the cat by the horseradish peroxidase (HRP) method. The reticular region around the trigeminal motor nucleus are known to contain many interneurons for masticatory motoneurons. After injections of HRP into the reticular regions around the trigeminal motor nucleus, HRP‐labeled neuronal cell bodies in the cerebral cortex were found in layer V. They were distributed bilaterally in the orbitofrontal cortical regions, mainly in the rostral extension of the orbital gyrus close to the presylvian sulcus; more were located in the floor and lateral bank of the presylvian sulcus than in the crown of the orbital gyrus. After injections of HRP conjugated with wheat germ agglutinin (WGA‐HRP) into these cortical regions, many labeled presumed axon terminals were distributed bilaterally in the reticular regions around the trigeminal motor nucleus; mainly in the region ventral to the trigeminal motor nucleus and in the intertrigeminal region between the main sensory trigeminal nucleus and the trigeminal motor nucleus. Terminal labeling in these regions was more prominent after WGA‐HRP injection into the lateral bank of the presylvian sulcus than after WGA‐HRP injection into the crown of the orbital gyrus. Thus, the present results indicate that the main part of the cortical region projecting directly to the reticular regions around the trigeminal motor nucleus in the cat is folded into the presylvian

ISSN:0092-7317    

DOI:10.1002/cne.902410308

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe thalamic relations of the caudal inferior parietal lobule and the dorsolateral prefrontal cortex in monkeys have been investigated with both anterograd and retrograde neuroanatomical tracing techniques.The results of these experiments indicate that the medial pulvinar nucleus (Pul.m.) is the principal thalamic relay to the gyral surface of the caudal inferior parietal lobule (area 7a). Within the Pul.m. there are two or three disklike aggregates of neurons which project to area 7a; these disklike neuronal aggregates are oriented from dorsomedial to ventrolateral and extend over most of the rostrocaudal extent of the nucleus. Within these disks there are rodlike clusters of neurons which are elongated in the rostrocaudal dimension of the thalamus, and which project in a topographically ordered manner to area 7a. Thus, the more rostrally located neurons within the Pul.m. disks project to more rostral parts of area 7a and, conversely, the more caudally located neurons project to the caudal part of this cortical field. Similarly, the medial part of each disk projects to the lateral part of area 7a while the laterally placed neurons project to the medial part of the cortical field. In addition to its input from the Pul.m., area 7a is also reciprocally connected with the magnocellular division of the nucleus ventralis anterior, with the nuclei which abut upon the medullary capsule of the laterodorsal nucleus, and with the suprageniculate nucleus and the nucleus limitans.The cortex on the lateral bank of the intraparietal sulcus (the so‐called lateral intraparietal area, LIP) projects principally to the lateral pulvinar nucleus (Pul.1) of the thalamus rather than to Pul.m. Area LIP has been found to project to the pregeniculate nucleus, the zona incdrta, the anterior pretectal nucleus, and the superior colliculus. Area 7a projects to none of these structures, but it does project to the posterior pretectal nucleus. The thalamic relations of the neighboring cortical regions, such as the prelunate gyrus and area 7b, are also distinct from those of area 7a. It thus seems that the prelunate gyrus is primarily interconnected with the Pul.l., and area 7b with the oral pulvinar nucleus. Taken together these different subcortical relationships provide further evidence for the view that the caudal inferior parietal lobule is not a homogeneous cortical area, but is composed of a number of subsidiary fields.The projection from the Pul.m. to the lateral prefrontal cortex arises from disklike aggregates of neurons, similar in their orientation to the neuronal disks that project to. area 7a. These two populations of Pul.m. neurons occupy partially overlapping zones so that after large dye injections into both the parietal and frontal lobes there are label‐free spaces between the sidklike neuronal aggregates. However, although they overlap, it is evident from double labeling experiments with distinct retrogradely transportedflourescent dyes that the two populations of cortically projecting neurons are essentially separ

ISSN:0092-7317    

DOI:10.1002/cne.902410309

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

年代:1985

数据来源: WILEY

摘要:

AbstractBrainstem nuclei projecting to the lumbar spinal cord in the monkey were identified by using horseradish peroxidase and the fluorescent dye granular blue. These retrogradely transported tracers were used in fluid and/or gel forms to determine the funicular trajectories of the brainstem‐spinal projections. The major descending components of the dorsal funiculus arose from the n. gracilis, n. cuneatus, and the n. of the solitary tract. Major components of the dorsolateral funiculus (DLF) came from the raphe complex, medullary and pontine reticular formation, locus coeruleus, Edinger‐Westphal n., and red n. Other nuclei giving rise to minor contributions to the DLF included n. gracilis, n. cuneatus, n. of the solitary tract, medial and spinal vestibular n., subcoeruleus, periaqueductal gray, interstitial n. of Cajal, n. of Darkschewitsch, and the anteromedian n. The major components of ventral cord paths (ventrolateral and ventral funiculi) arose from the raphe complex, the medullary and pontine reticular formation, lateral and spinal vestibular n., and the coerulean complex. Minor contributions to the ventral paths descended from the dorsal motor n. of X, n. of the solitary tract, medial vestibular n., paralemniscal reticular formation, dorsal parabrachial n., n. cuneiformis, periaqueductal gray, Kölliker‐Fuse n., and red n. The possible functional implications of the funicularr distribution of these descending pathways are discussed from the perspective of descending inhibition and pain modu

ISSN:0092-7317    

DOI:10.1002/cne.902410310

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

年代:1985

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.902410301

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

年代:1985

数据来源: WILEY