摘要:

AbstractThe CNS of cats including newly‐born, 2 day‐, 4 day‐, 10 day‐, 18 day‐, 3 week‐, 6 week‐ and 3 month‐old kittens and adults, were fixed by perfusion from the aorta with 1% osmium tetroxide in acetate‐veronal buffer, or with 2.5 to 3% glutaraldehyde or 4% formaldehyde in phosphate buffer and retreatment with osmium tetroxide after removal. The astrocytes in the intermediolateral horn of the thoracic spinal cord and in the neighboring lateral funiculus were examined under the electron microscope. The astrocytic mitochondria are larger than the neuronal ones at birth. They have a finely granular matrix and dispersed cristae mitochondriales. During the first 4 to 10 days after birth many of the astrocytic mitochondria enlarge, with an increase in the amount of matrix material and its crystallization into a filamentous array, forming “gliosomes.” Within two to three weeks, a bundle of crystalline filaments with a regular periodicity are formed in the matrix. The rough surfaced endoplasmic reticulum seems to be closely associated with the processes of gliosome formation. Namely, cisterane of the rough endoplasmic reticulum first accompany the growing mitochondria, then lose ribosomes on their proximal membranes, and finally change into vesicles of the smooth endoplasmic reticulum around the gliosomes and gliofilaments. The possible significance of these structural

ISSN:0092-7317    

DOI:10.1002/cne.901370302

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

年代:1969

数据来源: WILEY

摘要:

AbstractAcoustic nerve fibers, stained by the rapid Golgi method, were observed to bifurcate, after entering the ventral cochlear nucleus, into an ascending and a descending branch. Each branch was composed of fibers running parallel to each other with very little overlap. Prior to bifurcating, the acoustic nerve fibers gave rise to collaterals which ramified in the region of the bifurcations. Ascending branch fibers terminated in bulbs of Held and bore from zero to five additional collateral endings, including bulbs of Held. Descending, branch fibers gave rise within the posterior ventral cochlear nucleus to from zero to five collateral endings. These included large endings identified as bulbs of Held. Ascending and descending branch collaterals did not extend beyond 40–50 μ from their paret axons. Descending branch fibers projected into the dorsal cochlear nucleus. The area of the ventral cochlear nucleus dorsal to the region of bifurcations was innervated in a unique manner. This innervation occurred via long dorsally running collaterals arising from the most dorsal fibers of the ascending and descending branch projections.The data suggest morphological correlates of certain neurophysiological and behavioral findings in the areas of auditory localization and discriminati

ISSN:0092-7317    

DOI:10.1002/cne.901370303

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe cortical projection from the pulvinar has been studied in the cat with the help of stereotaxic coagulation and silver impregnation methods. The pulvinar of the cat projects fundamentally into the gyri suprasylvius posterior and medius, lateral bank of the posterior lateral sulcus, middle ectosylvian and anterior sylvian gyri. The projection to the gyrus suprasylvius is topologically organized overlapping with the projection of the n. lateralis posterior. The question of the ending of degenerated fibers in the parasplenial gyri is discussed.The thalamic degenerated fibers are present in the deeper layers of the cortex. There are however regions in the posterior suprasylvian gyrus in which degenerated fibers are present in the molecular layer as well as in the deeper layers. This different topographic distribution of the endings of the thalamic fibers is discussed with relation to the problem of the “sustaining” and “essential” thalamo‐cortical pr

ISSN:0092-7317    

DOI:10.1002/cne.901370304

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe efferent projection fibers from the rostral and the medial segments of the anterior olfactory nucleus have been studied using the Nauta or the Fink modification of the Nauta method for degenrating axons. Lesions were suitably placed by electrocoagulation. From the rostral segment of the anterior olfactory nucleus efferent fibers by way of the bulbar part of the anterior commissure were traced to the internal granular and the mitral cell layer of the normal side. Preterminal and terminal degeneration were traced by way of the homolateral lateral olfactory tract and these fibers ended in the lateral two‐thirds of the olfactory tubercle, the prepiriform, the piriform and the periamygdalar cortices and into the corticomedial segment of the amygdaloid complex. Degenerating fibers were also noted in the dorsomedial nucleus, the lateral habenular nucleus, the lateral hypothalamic area and in the supraoptic area of the same side where the lesion was made. In animals where the lesion was placed in the medial segment of the anterior olfactory nucleus the same fiber distribution was observed as reported when the lesion was placed in the rostral segment of the anterior olfactory nucleus. However, other areas were observed receiving fibers from the medial segment of the nucleus. These areas were the basolateral segment of the amygdaloid complex and the mammillary area

ISSN:0092-7317    

DOI:10.1002/cne.901370305

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe preganglionic parasympathetic neurons in the sacral spinal cord of the cat have been demonstrated by retrogade changes following section of the pelvic nerve.Transection of the pelvic nerve twice, a week apart, was necessary to produce reliable signs of chromatolysis in the preganglionic neurons. Serial sections of the sacral spinal cord were made and the location of affected cells plotted.The sacral parasympathetic nucleus was located in the intermediate region of S‐2 and S‐3. The majority of the perikarya were located in the intermediolateral cell column, but a significant number were also found in the intermediomedial column.The distribution of afferent fibers in the pelvic nerve was demonstrated by chromatolysis in cells of the dorsal root ganglia. Retrograde changes were limited to the ganglia of S‐2 and S‐3 in five cats, while a few cells with chromatolysis were found also in the S‐1 ganglion of

ISSN:0092-7317    

DOI:10.1002/cne.901370306

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe spinal cord origin and peripheral pathways of the sensory and motor nerves to the urinary bladder were delineated in the cat by stimulating the appropriate nerves near the urinary bladder and recording from the dorsal and ventral rootlets near the spinal cord.The parasympathetic preganglionic neurons originated in the sacral segments of the spinal cord and reached the bladder by way of the pelvic nerve. The preganglionic parasympathetic perikarya to the urinary bladder were distributed over a length of approximately 1.5 segments, centered near the junction of segments S‐2 and S‐3 in cats with a median arrangement of the lumbosacral plexus. Conduction velocities in preganglionic parasympathetic fibers to the bladder ranged from 46 to 2 M/sec with a mean maximal velocity of 18.2 M/sec.The major sympathetic pathway to the bladder was in the hypogastric nerve. Preganglionic sympathetic fibers originated in the lumbar spinal cord and traveled through the caudal mesenteric ganglion and hypogastric nerve to the urinary bladder. There were both ipsilateral and contralateral preganglionic and afferent fibers in this pathway. The preganglionic sympathetic neurons originated in segments L‐2 and L‐5. They were usually distributed over approximately 2 full segments centered near the junction of L‐3 and L‐4 in cats with a median arrangement of the lumbosacral plexus.Neurons involved in the micturition reflex may extend from the rostral end of the L‐2 segment to the caudal end of the S‐3 segment. The sympathetic preganglionic neurons were usually separated from the somatic and parasympathetic columns by segm

ISSN:0092-7317    

DOI:10.1002/cne.901370307

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe center median nucleus of the cat was damaged electrolytically by a horizontally introduced electrode through the cerebellum. After a postoperative survival of ten days to a month degenerated fibers were studied by a modified Nauta method. Direct connections of the center median nucleus of diffuse character were found terminating bilaterally in V–VI layers of the neocortex. Another cortical projection from the center median nucleus terminating in layers III–IV was limited to the anterior and middle regions of the lateral and suprasylvian gyri, the anterior ectosylvian and sylvian gyri and the cornal gyrus. Fibers to the contralateral cortex were found to pass through the corpus callosum.Threshold stimulation of the center median nucleus evoked recruiting response (with a short latency) only in the limited area of the cortex whose direct connections terminate in III–IV layers. Diffuse recruiting response was obtained only with the stronger stimulation. Following lesion of the center median nucleus, diffuse recruiting response, evoked by stimulation of other nonspecific nuclei, was not obtained in the area of the cortex whose III–IV layers recieve connections from the center median nucleus. This supports the view that diffuse recruiting response during stimulation of one nonspecific nucleus is evoked by intrathalamic sprading of impulses to other nonspecific

ISSN:0092-7317    

DOI:10.1002/cne.901370308

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

年代:1969

数据来源: WILEY

摘要:

AbstractOne group of rats was reared under conditions of environmental complexity, while their littermates served as isolation controls. The occipital cortex was 4.9% (p<0.01) and the hippocampus 5.7% (P<0.05) thicker in the environmental complexity rats than in the isolation control animals. Differntial cell counts demonstrated significant differences in neuroglia in the hippocampus.

ISSN:0092-7317    

DOI:10.1002/cne.901370309

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

年代:1969

数据来源: WILEY

摘要:

AbstractSecondary degeneration of foreleg afferents was traced in the prothoracic ganglion of the common wood ant (Formica lugubris Zett) with the aid of phase contrast and electron microscopy. The legs were amputated at the coxal level in 43 workers; 1–35 days were allowed for degeneration. Localization of degenerated sensory nerves in the entering nerve root and within the neuropil of the ganglion was opumal after 4‐10 days. Afferent fibers were found predominantly in the ipsilateral half of the ganglion. However, a few fibers seemed to cross the midline and to end in the medial portion of the contralateral side. No degenerations could be located within the cranial and caudal connectives. The significance of the findings with respect to the problem of functional localization pattern in the neuropil of an insect ganglion is discus

ISSN:0092-7317    

DOI:10.1002/cne.901370310

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.901370301

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

年代:1969

数据来源: WILEY