bluuebunny/crossref_metadata_2025 huggingface dataset:
Hereditary form of parkinsonism—dementia
Authors: Muenter Manfred D. , Forno Lysia S. , Hornykiewicz Oleh , Kish Stephen J. , Maraganore Demetrius M. , Caselli Richard J. , Okazaki Haruo , Howard Frank M. , Snow Barry J. , Calne Donald B.
Published: January 2005

In four generations of a family, 13 members were afflicted with an autosomal dominant disorder characterized by young age at onset, early weight loss, and rapidly progressive dopa‐responsive parkinsonism, followed later by dementia and, in some, by hypotension. Intellectual dysfunction began with subjective memory loss and objective visuospatial dysfunction and was followed later by decline of frontal lobe cognitive and memory functions. Neuropathological examination in 4 autopsied cases showed neuronal loss in the substantia nigra and locus ceruleus and widespread Lewy bodies, many of them in the cerebral cortex; those in the hypothalamus and locus ceruleus were often of bizarre shapes. Other findings were vacuolation of the temporal cortex, unusual neuronal loss and gliosis in the hippocampus (CA 2/3), and neuronal loss in the nucleus basalis. There were no neuritic plaques, neurofibrillary tangles, or amyloid deposits. Positron emission tomography in 3 patients showed decreased striatal uptake of fluorodopa. Neurochemical analysis of an autopsied brain showed a pronounced decrease in choline acetyltransferase activity in the frontal and temporal cortices and hippocampus and a severe depletion of striatal dopamine with a pattern not typical of classic Parkinson's disease.
Beneficial effects of L‐serine and glycine in the management of seizures in 3‐phosphoglycerate dehydrogenase deficiency
Authors: de Koning Tom J. , Duran Marinus , Dorland Lambertus , Gooskens Rob , van Schaftingen Emile , Jaeken Jaak , Blau Nenad , Berger Ruud , Poll‐The Bwee Tien
Published: January 2005

3‐Phosphoglycerate dehydrogenase (3‐PGDH) deficiency is an inborn error of serine biosynthesis. Patients are affected with congenital microcephaly, psychomotor retardation, and intractable seizures. The effects of oral treatment with amino acids were investigated in 2 siblings. L‐Serine up to 500 mg/kg/day was not sufficient for seizure control. Addition of glycine 200 mg/kg/day resulted in complete disappearance of seizures. Electroencephalographic abnormalities gradually resolved after 6 months. We conclude that 3‐PGDH can be treated effectively by a combination of L‐serine and glycine.
Familial spinocerebellar ataxia with cerebellar atrophy, peripheral neuropathy, and elevated level of serum creatine kinase, γ‐globulin, and α‐fetoprotein
Authors: Watanabe Mitsunori , Sugai Yoshiro , Concannon Patrick , Koenig Michel , Schmitt MichèLe , Sato Madoka , Shizuka Masami , Mizushima Kazuyuki , Ikeda Yoshio , Tomidokoro Yasushi , Okamoto Koichi , Shoji Mikio
Published: January 2005

Here, we report a familial spinocerebellar ataxia (FSCA), which has clinical features similar to Friedreich's ataxia, an ataxia with isolated vitamin E deficiency, and ataxia telangiectasia. However, the serum levels of creatine kinase, γ‐globulin, and α‐fetoprotein were elevated, and biochemical and genetic analyses ruled out diagnosis of these three ataxias as well as other FSCAs. Thus, this family is thought to have a new type of FSCA.
Hippocampal volumes in cognitively normal persons at genetic risk for Alzheimer's disease
Authors: Reiman Eric M. , Uecker Anne , Caselli Richard J. , Lewis Stephen , Bandy Daniel , De Leon Mony J. , De Santi Susan , Convit Antonio , Osborne David , Weaver Amy , Thibodeau Stephen N.
Published: January 2005

Brain imaging techniques have the potential to characterize neurobiological changes that precede the onset of cognitive impairment in persons at risk for Alzheimer's disease. As previously described, positron emission tomography (PET) was used to compare 11 cognitively normal persons 50 to 62 years of age who were homozygous for the ε4 allele of apolipoprotein E and 22 persons without the ε4 allele with a reported family history of Alzheimer's dementia who were matched for sex, age, and level of education. The ε4 homozygotes had significantly reduced glucose metabolism in the same brain regions as patients with Alzheimer's dementia; the largest reduction was in the posterior cingulate cortex. As described here, magnetic resonance imaging (MRI) was used to compare hippocampal volumes in the same subject groups. The ε4 homozygotes showed nonsignificant trends for smaller left and right hippocampal volumes; overall, smaller hippocampal volumes were associated with reduced performance on a long‐term memory test. Whereas PET measurements of cerebral glucose metabolism begin to decrease before the onset of memory decline, MRI measurements of hippocampal volume begin to decrease in conjunction with memory decline in cognitively normal persons at risk for Alzheimer's disease.
Functional brain networks in DYT1 dystonia
Authors: Eidelberg David , Moeller James R. , Antonini Angelo , Kazumata Ken , Nakamura Toshitaka , Dhawan Vijay , Spetsieris Phoebe , DeLeon Deborah , Bressman Susan B. , Fahn Stanley
Published: January 2005

Early‐onset idiopathic torsion dystonia (ITD) is an autosomal dominant hyperkinetic movement disorder with incomplete penetrance, associated with a 3 base‐pair deletion in the DYT1 gene on chromosome 9q34. To determine the metabolic substrates of brain dysfunction in DYT1 dystonia, we scanned 7 nonmanifesting and 10 affected DYT1 carriers and 14 normal volunteers with [18F]fluorodeoxyglucose and positron emission tomography. We found that DYT1 dystonia is mediated by the expression of two independent regional metabolic covariance patterns. The first pattern, identified in an analysis of nonmanifesting gene carriers was designated movement free (MF). This abnormal pattern was characterized by increased metabolic activity in the lentiform nuclei, cerebellum, and supplementary motor areas. The MF pattern was present in DYT1 carriers with and without clinical manifestations and persisted in DYT1 dystonia patients in whom involuntary movements were suppressed by sleep. The second pattern, identified in an analysis of affected gene carriers with sustained contractions at rest, was designated movement related (MR). This pattern was characterized by increased metabolic activity in the midbrain, cerebellum, and thalamus. The expression of the MR pattern was increased in waking DYT1 patients with sustained dystonia, compared with DYT1 carriers who were unaffected or who had dystonia only on action, as well as normal controls. MR subject scores declined significantly with sleep in affected DYT1 patients but not in normal controls. These findings indicate the penetrance of the DYT1 gene is considerably greater than previously assumed. ITD is mediated through the interaction of functional brain networks relating separately to gene status and to abnormal movement.
Acquired idiopathic generalized anhidrosis with isolated sudomotor neuropathy
Authors: Miyazoe Seiji , Matsuo Hidenori , Ohnishi Akio , Tajima Fumihiro , Fujishita Satoshi , Ichinose Katsuhiro , Shibuya Noritoshi
Published: January 2005

The pathogenesis and underlying lesion of acquired idiopathic generalized anhidrosis (AIGA) are apparently heterogeneous. We report a patient with AIGA in whom the eccrine glands were histologically normal. However, electron microscopic examination showed markedly low numbers of nerve terminals and unmyelinated axons associated with the eccrine glands. Our laboratory investigations suggest that degeneration of postganglionic sympathietic cholinergic nerve may be the underlying pathogenetic mechanism of anhidrosis in this patient.
Correlation between cytomegalovirus infection and IgM anti‐MAG/SGPG antibody–associated neuropathy
Authors: Yuki Nobuhiro , Yamamoto Takako , Hirata Koichi
Published: January 2005

IgM anti–myelin‐associated glycoprotein (anti‐MAG)/sulfated glucuronyl paragloboside (SGPG) antibody is found in some patients with chronic polyneuropathy (CP). An antigen‐driven process is considered to induce this autoantibody, but the agent has yet to be identified. It has been reported that sera from cytomegalofvirus (CMV)‐infected patients contained anti‐SGPG antibody. To clarify the mechanism of the production of the anti‐MAG/SGPG antibody, we investigated CMV DNA in sera from 26 patients with IgM anti‐MAG/SGPG antibody–positive CP. Twenty‐three (88%) had CMV DNA. The positive frequency was significantly higher than the freqencies in sera from patients with IgM anti‐MAG/SGPG–negative CP, the other disease controls, and the normal control subjects. There were no statistical differences in the frequencies of Epstein‐Barr virus DNA between anti‐MAG/SGPG–positive and anti‐MAG/SGPG–negative CP and between anti‐MAG/SGPG–positive CP and each disease control. Moreover, no herpes simplex virus 1 DNA was detected in the sera from patients with anti‐MAG/SGPG–positive CP. The strong correlation of anti‐MAG/SGPG–positive CP with the presence of serum CMV DNA suggests that CMV infection induces the IgM anti‐MAG/SGPG antibody.
Antibodies against Helicobacter pylori were detected in the cerebrospinal fluid obtained from patients with guillain‐barré syndrome
Authors: Chiba Susumu , Sugiyama Toshiro , Matsumoto Hiroyuki , Hisano Kazunari , Awakawa Teruhito , Hiura Kazumi , Saitoh Masaki , Imai Kohzoh
Published: January 2005

We examined the antibodies against Helicobacter pylori proteins in the cerebrospinal fluid (CSF) of 7 patients with Guillain‐Barré syndrome (GBS). Crude H. pylori antigens, fractionated heat shock protein (HSP), and urease B (UB) from H. pylori antigens were separated by SDS‐PAGE. With Western blot analysis, four of seven CSF samples had several IgG antibodies against H. pylori proteins, including HSP and UB. No cross reactivity against Campylobacter jejuni was observed. These antibodies may be involved in the immune responses of patients with GBS.
D2 receptor binding in dopa‐responsive dystonia
Authors: Künig Gabriella , Leenders Klaus L. , Antonini Angelo , Vontobel Peter , Weindl Adolf , Meinck Hans M.
Published: January 2005

We have studied dopamine D2 receptor binding by [11C]raclopride positron emission tomography in 14 patients with dopa‐responsive dystonia (DRD). Data were compared with 16 levodopa‐treated patients with Parkinson's disease (PD) and 26 healthy controls. The results revealed an elevated [11C]raclopride binding index in the putamen and caudate nucleus of DRD patients compared with controls as well as significant elevation in the caudate nucleus compared with PD patients. The increase of [11C]raclopride binding may be interpreted either as reduced tracer displacement by endogenous dopamine, or as an alteration of the receptor features due to chronic dopamine deficiency. The difference in [11C]raclopride binding in DRD and PD patients in the caudate nucleus suggests that this structure may be of pathophysiological relevance in the presentation of the clinical features of both diseases.
Adult polyglucosan body disease in Ashkenazi Jewish patients carrying the Tyr329 Ser mutation in the glycogen‐branching enzyme gene
Authors: Lossos Alexander , Meiner Zeev , Barash Varda , Soffer Dov , Schlesinger Ilana , Abramsky Oded , Argov Zohar , Shpitzen Shoshi , Meiner Vardiella
Published: January 2005

Adult polyglucosan body disease (APBD) is a late‐onset, slowly progressive disorder of the nervous system caused by glycogen branching enzyme (GBE) deficiency in a subgroup of patients of Ashkenazi Jewish origin. Similar biochemical finding is shared by glycogen storage disease type IV (GSD IV) that, in contrast to APBD, is an early childhood disorder with primarily systemic manifestations. Recently, the GBE cDNA was cloned and several mutations were characterized in different clinical forms of GSD IV. To examine whether mutatins in the GBE gene account for APBD, we studied 7 patients from five Jewish families of Ashkenazi ancestry. The diagnosis was based on the typical clinical and pathological findings, and supported by reduced GBE activity. We found that the clinical and biochemical APBD phenotype in all five families cosegregated with the Tyr329Ser mutation, not detected in 140 controls. As this mutation was previously identified in a nonprogressive form of GSD IV and was shown in expression studies to result in a significant residual GBE activity, present findings explain the late onset and slowly progressive course of APBD in our patients. We conclude that APBD represents an allelic variant of GSD IV, but the reason for the difference in primary tissue involvement must be established.
Neuromuscular blockade by IgG antibodies from patients with Guillain‐Barré syndrome: A macro‐patch‐clamp study
Authors: Buchwald Brigitte , Toyka Klaus V. , Zielasek Jürgen , Weishaupt Andreas , Schweiger Susanna , Dudel Josef
Published: January 2005

Guillain‐Barré syndrome (GBS) is often associated with serum antibodies to glycoconjugates such as GM1 and GQ1b. The pathogenic role of these antibodies and other serum factors has not yet been clarified. We have investigated the effect of serum, plasma filtrate, and highly purified IgG and IgM from 10 patients with typical GBS on motor nerve terminals in the mouse hemidiaphragm. Quantal endplate currents were recorded by means of a perfused macro‐patch‐clamp electrode. The plasma filtrate of all GBS patients led to a 5‐ to 20‐fold reduction of evoked quantal release within 7 to 15 minutes of continuous superfusion. In 4 patients, the amplitudes of single quanta were clearly reduced (by 10–66% of control values), indicating an additional postsynaptic action. Blocking effects could be reversed to a variable degree within 15 to 18 minutes after washout. Purified IgG was as effective as native serum, whereas a purified GBS IgM fraction did not block transmission. Sera from convalescent patients and IgM from healthy subjects were without blocking effect. The effects were complement independent and there was no link to the presence (in 6 patients) or absence (in 4 patients) of detectable antibodies to GM1 or GQ1b. In GBS, antibodies to an undetermined antigen depress the presynaptic transmitter release and, in some cases, the activation of postsynaptic channels. We suggest that weakness in the acute stage of GBS may be caused in part by circulating antibodies.
The change in volume of the olfactory and accessory olfactory bulbs of the albino rat during postnatal life
Authors: Smith C. G.
Published: January 2005

Transverse sections of the olfactory bulbs were prepared for seventy‐one male and six female albino rats, all of which were of the Experimental Colony strain obtained from The Wiostar Institute. These were selected and grouped according to age so that representative ages throughout the whole of the postnatal life cycle are available.
The cochlear nuclei in the common porpoise, Phocaena phocaena
Authors: Osen Kirsten Kjelsberg , Jansen Jan
Published: January 2005

The structure of the primary cochlear nuclei in three specimens of the common porpoise, Phocaena phocaena, has been studied in transverse and sagittal sections stained for cells (Nissl) and myelin sheaths. A rudimental dorsal cochlear nucleus and a very large ventral cochlear nucleus were found. The large cochlear nerve (nine tenths of the entire VIII nerve) enters the rostral pole of the ventral cochlear nucleus within which it fans out to form ascending and descending fibers. Five subdivisions were distinguished in the ventral nucleus, viz., the anterior part, the posterior part, the dorsolateral part, the dorsomedial part, and the interstitial part.

Great similarity exists between the Phocaena and other toothed whales with regard to the structure of the cochlear nuclei. Neither seems any principal difference to exist in this respect between the Phocaena and the landliving mammals, especially when compared with the primates which have likewise a poorly differentiated dorsal nucleus. The five subdivisions of the ventral nucleus of Phocaena presumably are the homologues of the subdivisions distinguished by Fuse ('13) and Lorente de Nó ('33) in the corresponding nucleus of terrestrial mammals. The enormous size of the ventral cochlear nucleus is the only reliable criterion observed that might reasonably be associated with the extraordinary sense of hearing in Cetacea.
A simple method for determining cerebralization. Brain weight and intelligence
Authors: Krompecher S. T. , Lipák J.
Published: January 2005

By means of comparing the weight of the brain with the weight of the spinal cord the authors seek a way to appraise the intelligence of the individual. Authors' concept, on the one hand, unites the advantages of the other methods, on the other hand, it reduces their errors. Namely, the weight of the spinal cord stands in proportion to the bulk of the body of the individual, its surface and its functions, while the brain — with the exception of a small somatic part standing in constant correlation with the spinal cord — serves as the seat of the intellect. In different vertebrates the weight of the brain surpasses that of the spinal cord in different degrees. The weight of the brain in the frog is twice as high as that of its spinal cord, in the dog six times, in the cerkof monkey 14 times, in the orang‐utan 33 times, and in man 43 times. Pertinent detailed data are revealed by the table.
The localization, in the nucleus ambiguus of the rabbit, of the cells of origin of motor nerve fibers in the glossopharyngeal nerve and various branches of the vagus nerve by means of retrograde degeneration
Authors: Lawn A. M.
Published: January 2005

The glossopharyngeal nerve and the vagus nerve or its branches were cut individually or in various combinations in different rabbits. In two animals the cricothyroid muscle of the larynx was dissected away. The distribution in the nucleus ambiguus of the neurons of origin of motor fibers in the various nerve branches was deduced from the retrograde degeneration observed in these cells after the appropriate branch had been cut or muscle had been removed. The part of the glossopharyngeal nerve associated with the nucleus ambiguus was found to arise from a compact mass of cells lying level with, but ventrolateral to, the rostral tip of the principal column of the nucleus, forming the rostral extremity of the medial column. The remainder of the medial column was shown to give rise to axons innervating the cricothyroid muscle. The principal column contains a group of cells innvervating the pharynx and soft palate and a group innervating the esophagus, but there was considerable rostrocaudal overlap between these two groups. Some evidence is presented showing that the cells for the cervical esophagus are not clearly separated rostrocaudally from the cells for the abdominal esophagus. The cells of the diffuse formation innervate the intrinsic muscles of the larynx excepting the cricothyroid muscle.
Patterns of form and function in the central nervous system of Ariolimax
Authors: Turner R. S.
Published: January 2005

The external and internal morphology of the central nervous system of the large terrestrial gastropod Ariolimax columbianus are shown to be typical of the general pattern for stylommatophoran pulmonates. This typicality recommends Ariolimax as a useful normal model for experimental investigation of the molluscan nervous system. The central nervous system of this form was reconstructed by tracing every section of a horizontally serially sectioned specimen onto transparent acetate tracing film at a magnification of 32 ×. The position of all cells greater than 50 m̈ in diameter as well as the locations of neuropil, septa, exits of the various nerves, etc., were all carefully indicated on this model. By comparing sections serially cut in different planes with the reconstruction it becomes apparent that many, if not most, of the larger cells and constellations of cells are identifiable from animal to animal. This finding is consistent with the assumption that basic stereotyped responses most probably reflect stereotyped anatomical patterns. Fixed neuronal patterns in turn suggest basic identifiable discharge patterns over the major nervous pathways. By double beam recording it is demonstrated that recognizable “core discharge” patterns from the central nervous system can indeed be distinguished following various controlled afferent inputs. The results of this study support the concept of a physiologically and anatomically patterned, as opposed to a randomly functioning, neuropil.
Electron microscopic studies of the dentate gyrus of the rat. I. Normal structure with special reference to synaptic organization
Authors: Laatsch R. H. , Cowan W. M.
Published: January 2005

The fine structure of the dentate gyrus of the rat has been studied in glutaraldehyde perfused material. With the exception of the short axon association cells, the major components of each of the three layers of the gyrus have been identified, and a detailed account is given of the synaptic organization of the dentate granule cells.

The granule cells have most of the features typical of small neurons and although they contain no large aggregates of granular endoplasmic reticular they exhibit a variety of cisternal specializations. In the granule cell layer numerous axo‐somatic and axo‐dendritic synapses have been observed, and on occasion a single presynaptic fiber has been seen to contact the soma of one cell and a proximal dendrite of another. In the inner part of the molecular layer the majority of synapses are upon the main dendritic shafts of the granule cells but many also contact short dendritic spines. In the outer two‐thirds of this layer most presynaptic fibers end upon long dendritic spines some of which are characterized by a prominent projection from the subsynaptic surface into the presynaptic process. The unmyelinated axons of the granule cells establish many en passant contacts with dendrites and spines of CA4 pyramids before ending in large presynaptic bags which may contain a number of large agranular vesicles (up to 2,000 Å in diameter) and vesicles with dense cores.
The lateral cervical nucleus of the Japanese monkey (Macaca fuscata)
Authors: Mizuno Noboru , Nakano Katsuma , Imaizumi Masamichi , Okamoto Michio
Published: January 2005

Based on the normal histological findings and the organization of the spinal afferents revealed by the Nauta and the Marchi methods, a cell group corresponding to the lateral cervical nucleus (NCL) of the cat was identified in the first and the second cervical segments of the spinal cord of the Japanese monkey (Macaca fuscata).

The nucleus begins to appear at the level of the caudal end of the gracile nucleus and gradually disappears within the caudal half of the second cervical segment of the cord. The nucleus consists of medium‐sized and small‐sized nerve cells and receives spinal afferents ascending through the lateral funiculus, probably chiefly through the posterior spino‐cerebellar tract, from lower levels of the spinal cord. The spinal afferents seem to take origin entirely, or at least chiefly, from the ipsilateral spinal gray and to terminate in the nucleus without any localization. Some problems concerning the lateral cervical nucleus as the site of the spino‐thalamic tract have also been discussed from the point of view of comparative anatomy.
Electron microscopy of classically stained astrocytes
Authors: Vaughn James E. , Pease Daniel C.
Published: January 2005

Sections of cat cerebral cortex stained for astroytes by the Cajal gold chloride‐sublimate method have been examined with the electron microscope. Small, electron‐opaque dots representing gold deposition are specifically concentrated in cells which have swollen, clear perikaryal areas and processes which terminate as perivascular end feet. The appearance of these cells is very similar to the “watery” cells identified as astrocytes in some of the early electron microscopic investigations of central nervous tissue. Neurons and oligodendrocytes, in those layers of cortex examined electron microscopicallly, contain only a small number of gold particles.

A possible morphological substrate explaining the sepecificity of the Cajal method for astrocytes is discussed.
Visual and non‐visual factors in the centripetal stimulation of postnatal growth of the visual centers in mice
Authors: Gyllensten Lars , Malmfors Torbjörn , Norrlin‐Grettve Marie‐Louise
Published: January 2005

The diameter of cell nuclei and mean volume of internuclear material per nucleus were determinated in the visual corte, lateral geniculate bodies and superior colliculi in growing mice. The influence of bilateral removal of the eyes at birth was studied, and compared with the effects of rearing the animals in complete darkness from birth.

Bilateral removal of the eyes caused a decrease in nuclear size and relative voulme of internuclear material at two and four months after birth. Compared to similar changes in dark‐reared mice, the decreases were greater in the mice without eyes, particularly in the subcortical visual centers. After eye removal, no growth of nuclei and internuclear material was observed between two and four months of age. This is in contrast to the findings in dark‐reared mice, in which partial “normalization” occurred during prolonged stay in the dark betwen two and four months. It is concluded that the postnatal growth and differentiation of the visual centers are stimulated both by visual stimuli and by non‐visual stimuli from the optic nerve fibers.
Somatotopic organization of raccoon dorsal column nuclei
Authors: Johnson J. I. , Welker W. I. , Pubols B. H.
Published: January 2005

Somatotopic organization was demonstrated by means of microelectrode mapping studies of three somatic sensory nuclear regions in the raccoon medulla.

Projections of peripheral receptive fields in the cuneate‐gracile nuclear complex occur iteratively in rostro‐caudal columns. These projections are organized into a detailed 3‐dimensional pattern, in contrast to the more diffuse intermingling of such projections in the spinal dorsal roots and columns. This indicates that afferent fibers are re‐sorted before synaptic termination. In the extensive representation of the volar hand, there are distinct subnuclei, delineated by intervening fiber laminae, each containing the projections from one of the forepaw digits.

Units in the external‐cuneate nucleus responded only to stimulation of deeperlying tissues in anterior body regions. These projections were also somatotopically organized. Retrograde degeneration studies indicated that some cells, in that region where cuneate‐gracile adjoins external‐cuneate, may project through both the ipsilateral cerebellar peduncles and the contralateral midbrain.

The spinal trigeminal nucleus adjoining the cuneate‐gracile complex displayed many characteristics similar to those of the latter.

Neighboring, although anatomically distinct, regions contained projections from neighboring peripheral receptive fields.
The development of hippocampal and dorsolateral pallial regions of the cerebral hemisphere in fetal rabbits. VI. Ninety millimeter stage, cortical differentiation
Authors: Stensaas L. J.
Published: January 2005

The structure of the cerebral hemisphere of 90 mm rabbit embryos was studied with aniline and Golgi stains and a comparison of cortical plate morphology was made with earlier stages. Neuronal differentiation was inferred to be a continuous process since cells forming the base of the cortical plate gradually increase in size from 29 mm through 90 mm stages. However, differentiation also appeared to be most rapid among cells situated near the marginal lamina. Analysis of the development of large pyramids of layer V in the pallial region provided the most convincing proof for this conclusion. This mode of cortical development suggests the possibility that embryonic synapses are estabilished sequentially along the apical dendrites of pyramidal cells as the cortical plate grows through the addition of new cells. This process is postulated to occur in a “critical zone” at the boundary of the marginal lamina with the cortical plate.

The development of interneuronal neuropile in the lower part of the cortical plate of 90 mm embryos seems to be correlated not only with the growth of basal dendrites and axon collaterals, but also with the simultaneous appearance of true astrocytes and oligodendrocytes.
Development of fine structure of spinal cord in monkey fetuses. II. Pre‐reflex period to period of long intersegmental reflexes
Authors: Bodian David , Melby Edward C. , Taylor Naomi
Published: January 2005

A series of 13 macaque fetuses of estimated ovulation ages 42 to 51 days (17 to 41 mm) was subjected to behavioral analysis with umbilical cord intact (in and out of the amnion), and to light and electron microscopic analysis of the cervical spinal cord. This period is a critical one in terms of onset and early development of spontaneous activity and of cutaneous reflexes. Behavioral criteria, reinforced by well‐defined microscopic characteristics, suggested a grouping of specimens into three major stages, namely, a pre‐reflex group (Stage 1: 17–22 mm); a group in the period of onset of primitive spontaneous activity and of precocious local cutaneous reflexes in the trigeminal‐cervical region (Stage 2: 24 to 28 mm); and a group characterized by the development of more vigorous activity, spontaneous and otherwise, and of long intersegmental and crossed reflexes (Stage 3: 32 to 41 mm). The evidence suggests that junctional differentiation and occurrance of a cluster of agranular spheroid synaptic vesicles characterize the primitive synaptic knobs which appear on motoneuron dendrites coincident with earliest reflexes. Onset of active long intersegmental reflexes in Stage 3 is coincident with development of axosomatic synaptic knobs, and of F type (flattened) synaptic vesicles in a rapidly increasing fraction of all synaptic bulbs in the motoneuron neuropil. Total volume of all synaptic bulbs increases gradually as a fraction of the volume of the motoneuron neuropil until birth, but a steep increase in proportionate number of F type synaptic knobs occurs in Stage 3.
A third neuroglial cell types. An electron microscopic study
Authors: Vaughan James E. , Peters Alan
Published: January 2005

During a study of developing optic nerves, it was necessary to reevaluate the earlier electron microscopic evidence that only two neuroglial types, oligodendrocytes and fibrous astrocytes, are contained within central white matter. A reexamination of adult optic nerves showed that in addition to these two kinds of cells, a third morphologically distinct cell type exists. Cells of this third neuroglial variety are small and their cytoplasmic density is less than that of all forms of oligodendrocytes but slightly more than that of astrocytes. Neither the filaments and glycogen particles characteristic of astrocytes nor the microtubules typical of oligodendrocytes are observed in the third type of neuroglia. Dense, laminar bodies and fat droplets are frequently present within their cytoplasm, and profiles of the granular endoplasmic reticulum consist of long, stringy cisternae. Fetal and early postnatal optic nerves contain a cell type with the same morphological characteristics. This suggests that the third type of neuroglia in adult nerves may represent cells of a similar nature to the multipotential stem cells of other tissues. Some of the characteristics of the third type of neuroglia are reminiscent of the microglia of classical light microscopy, but data from developing nerves indicates that the former are derived from neuroectodermal matrix cells and not from invading mesenchymal elements.
Cholinesterases in the area subpostremas. A region adjacent to the area postrema in the cat
Authors: Gwyn David G. , Wolstencroft John H.
Published: January 2005

A region in the medulla oblongata of the cat, which has been named the area subpostrema, has been described. This area is unique in demonstrating strong staining for both specific and pseudocholinesterase in the walls of capillaries and also in an arc of neuropil which partly surrounds these capillaries. Over most of its length the area subpostrema lies immediately ventral or ventrolateral to the area postrema, dorsal to the dorsal motor nucleus of the vagus and dorsomedial to the tractus solitarius. The area subpostrema, unlike the area postrema, is not stained by the vital dye trypan blue. A group of capillaries in the inferior olivary nucleus which demonstrate specific but not pseudocholinesterase activity have also been described.

Using Nissl stains and silver impregnation techniques the area subpostrema has been found to contain a few small neurones and many unmyelinated nerve fibers. Some nerve fibers within the area subpostrema demonstrate specific cholinesterase activity.

The relation of the area subpostrema to the nucleus of the tractus solitarius has been discussed. It has been suggested that the area subpostrema might have receptor functions related to autonomic control.
A study of fiber systems within the spinal cord of the domestic pig that subserve pain
Authors: Breazile James E. , Kitchell Ralph L.
Published: January 2005

A total of 21 domestic pigs were used in a study of spinal cord fiber systems which subserve a pain response in the pig. Distribution of fiber systems were determined by the placement of various lesions into the spinal cord and examining the animal for its ability to give a complete pain response. The Swank‐Davenport modification of the Marchi technique for staining degenerating myelnated fibers was used to determine the pattern of trajectory of myelinated fibers along the spinal cord. Lesions were made at the cervical level in three animals and resulting pattern of degenerating fibers was compared with those of the other animals in which the lesions had been placed at lower thoracic levels. In most animals the lesions were limited to a single site on the spinal cord, but in six animals staggered, bilateral hemisections were made to determine whether or not these fiber systems are as diffuse in the pig as has been reported for the cat.

The spinal cord fiber systems which subserve a pain response in the pig are located generally within the ventrolateral quadrant of the spinal cord. It was found that only a small portion of one lateral funiculus just ventral to the dorsal and ventral spinocerebellar tracts, if left intact, was sufficient for the elicitation of a pain response from either rear limb.

The results presented here indicate that the fiber systems in the spinal cord of the pig which subserve pain responses are more diffuse than in carnivora or in primates.
Direct projections from the masseteric nerve to the mesencephalic nucleus
Authors: Smith R. Dale , Marcarian Heront Q. , Niemer William T.
Published: January 2005

The caliber spectrum of the nerve to the masseter muscle of the cat was found to be unimodal, ranging from 1 to 16 μ, with the majority of the fibers in the 4‐8 μ range. The upper 25%, which includes the afferent propriococoptive fibers, averaged 10.4 μ. The nerve to the masseter was stimulated and evoked potentials were recorded from the ipsi‐ and contralateral mesencephalic nuclei of the trigeminus and from the contralateral nerve. The average latencies were 0.846, 0.935 and 1.46 msec respectively. The mesencephalic nucleus was stimulated and evoked potentials were recorded from the contrlateral nucleus with an average latency of 0.385 msec. Analysis of the latencies of the responses recorded from the ipsilateral nucleus suggested that about half of the fibers of the nerve to the masster projected directly and the other half projected by way of an intervening synapse. A similar distribution of the fibers to the contralateral nucleus was deduced from the recorded latencies. Potentials recorded in the nuclei as a result of stimulation of the contralateral nucleus demonstrated that there were direct internuclear pathways without intervening synapses. The latencies of potentials recorded in the nerve as a result of stimulation of the contralateral nerve indicated that there was always at least one synapse intervening. It was also shown that there were direct projections from the nerve of the masseter to the contralateral motor nucleus of V. The work confirms our earlier report of bilateral projections from a muscle of mastication to the mesencephalic nuclei and provides a pathway for bilteral simultaneous activation of the muscles of mastication resulting from stimulation of unilateral tension receptors.
The frequency of occurrence of Barnes' ventrolateral pyramidal tract
Authors: Mizuno Noboru , Nakamura Yasuhisa , Okamoto Michio
Published: January 2005

In order to study the frequency of occurrence of Barnes' ventrolateral pyramidal tract, the lower parts of the medulla oblongata and the upper three cervical segments of the spinal cords of 210 adult Japanese were examined histologically.

The tracts were encountered in 43 out of 210 cases (20.5 ± 2.8%); bilaterally in (7.6 ± 1.8%), and unilaterally in 27 (12.9 ± 2.3%) cases. Consequently the tracts were found to be present in 59 out of 420 sides (14.0 ± 1.7%). Sex diffierence was not statistically significant (χ2 = 0.6, d.f. = 1, p > 0.25).
Somatotopic organization of mechanoreceptor units in the trigeminal nuclear complex of the macaque
Authors: Kerfl F. W. L. , Kruger L. , Schwassmann H. O. , Stern R.
Published: January 2005

The properties of neurons in the sensory trigeminal nuclear complex of macaque monkeys have been investigated by a systematic exploration of the principal sub‐divisions in an attempt to define somatotopic organization, modality representation, receptive field size and adaptive properties. Particular attention was paid to several discrepancies in the literature on the cat trigeminal complex. The results suggest that each cutaneous locus is represented by a rostro‐caudally oriented column of neurons possessing comparable properties and receptive field sizes at all levels examined in deeply anesthetized animals. A consistent somatotopic pattern with minor variations, was evident at all rostro‐caudal levels. Criteria for distinguishing “spinothalmic” and “lemniscal” neuron properties in appropriate portions of the sensory complex (inferred from human data) could not be identified. Neurons in adjacent structures may respond to crude stimuli and lack distinct receptive fields, but it is unlikely that these are related to an afferent “pain” pathway.
Degeneration in the dorsal lateral geniculate nucleus of the rat following interruption of the retinal or cortical connections
Authors: Montero V. M. , Guillery R. W.
Published: January 2005

Two distinct fiber systems are recognizable in the dorsal lateral geniculate nucleus of the rat. One consists of small bundles running in a transverse plane from the ventrolateral to the dorsomedial parts of the nucleus, and the other is made up of longitudinal fibers which pass approximately antero‐posteriorly through the nucleus parallel to the columns of cells that represent restricted retinal areas (Montero et al., '68).

The Nauta method, used after suitable lesions, shows that the transverse bundles carry corticofugal and retinogugal fibers. The former lie mainly in the ventromedial parts of the nucleus and the latter in the dorsolateral parts, but the two groups are also mingled within individual transverse bundles. Both groups send fibers into the lateral geniculate nucleus and each also continues beyond the nucleus. The fibers that ramify in the nucleus leave the transverse bundles and run in the longitudinal system as they break up into a pericelluar plexus. There is evidence that both groups have a terminal distribution along the lines of projection of retinal points.

Four days after a lesion within visual area I the degenerating corticogeniculate fibers form a fine plexus limited to the anterior half of the segment that would show retrograde cell degeneration with longer survival times. Seven and 13 days following a cortical lesion the retrograde cell changes obscure the fine corticogeniculate degeneration, but coarse geniculocortical fibers that are undergoing indirect Wallerian degeneration can be seen in the longitudinal system.
Autoradiographic study of histogenesis in the mouse olfactory bulb I. Time of origin of neurons and neuroglia
Authors: Hinds James W.
Published: January 2005

Time of origin (final cell division) of neurons and neuroglia of the mouse olfactory and accessory olfactory formations was determined by autoradiography. Animals were injected with thymidine‐H3 at various developmental stages and killed at or near maturity. In the olfactory formation mitral cells (the largest neurons) arise first, mainly over the three day period from the eleventh day of gestation (E11) to E13, tufted cells chiefly from E13 to E18, and granule cells (the smallest neurons) mainly from E18 to postnatal day 20. Most of the smaller and more superficial peripheral tufted cells arise later than the deeper and larger middle and internal tufted cells. All three types of granule cells have a time of origin extending well into postnatal life, with internal granule cells arising over a longer and later period than periglomerular cells or granule cells of the mitral cell layer. Neuroglial precursors undergo final cell division chiefly between E17 and P10. In the phylogenetically less evolved accessory olfactory formation, mitral cells originate earlier than their homologues in the olfactory formation; mitral cells principally from E10 to E12 and granule cells chiefly from E12 to E18. The results support the concept that some germinal layers of the central nervous system are programmed to produce a succession of cell types, larger cells before smaller ones.
Relationship of myelin internode elongation and growth in the rat sural nerve
Authors: Schlaepfer William W. , Myers Fay K.
Published: January 2005

The lengthening of myelin internodes along peripheral nerve fibers was studied in rat sural nerve during the period of myelination and subsequent growth. Sural nerves were examined from 34 animals ranging in age from 2 to 140 days. Analyses of osmicated, epon‐embedded and transversely sectioned nerves indicated that myclination of rat sural nerve commenced in the two to five day period and continued until day 20. Direct measurements of consecutive myelin internodes along representative teased fibers disclosed a progressive increase of internode length and fiber diameter. A direct relationship was shown between the rate of increment of the largest internodes and the longitudinal growth rate of the rat hind limb as determined by the combined lengths of the disarticulated femur and tibia. Increases of internode lengths among the entire population of myelinated fibers also appeared to correlate with the longitudinal growth pattern of the hind limb. This was assessed by comparing the size distribution of myelinated fibers in adult sural nerve with a theoretical distributional profile based upon the assumption that internode length is solely determined by amount of longitudinal growth after myelination. Assuming that internode elongation is determined by growth, it was shown that the quantity of longitudinal growth after myelination could account for the size and distribution of all myelin internodes in the adult sural nerve. In addition, the relationships between myelin internodes and fiber size at different ages was expressed by slopes of the regression lines. A significant change in this value for sural nerve fibers in the 30–40 day age period indicated that there was an increase of composite fiber diameter relative to internode length during the interval. During the remaining periods of growth, the diameters of myelinated fibers increased at a rate comparable to the increase of internode length.
Retinal structure in the smooth dogfish, Mustelus canis: Light microscopy of photoreceptor and horizontal cells
Authors: Stell William K. , Witkovsky Paul
Published: January 2005

Photoreceptor and horizontal cells in retinas of the smooth dogfish were impregnated by the rapid Golgi method. Cones as well as rods are present; there are hundreds of rods per cone. The rod synaptic endings are small spherules which send out basal processes (telodendria). The cone synaptic endings are large pedicles which also extend telodendria.

Horizontal cells of three distinctive varieties are segregated in vertically separate layers. Horizontal cells of the first (external) row are thick and cuboidal. They send out processes which enter into the invaginations in rod spherules. These cells and their processes cover a circular to elliptical field measuring 75–125 by 125–200 μm. They probably contact every rod in this field. Horizontal cells of the second (intermediate) row are flattened and stellate. Their processes also enter into the rod spherules. These cells cover a circular to elliptical field slightly larger than that covered by cells of the first row. Although they appear not to contact every rod in their field, the fields of adjacent cells of this type overlap. Every rod, therefore, probably contacts one horizontal cell of the second row as well as one of the first row. Horizontal cells of the third (internal) row are stellate, with a few long cylindrical horizontal processes. Finer vertical processes go from these to contact cone pedicles. Probably each cone contacts one such process, and each third‐row horizontal cell contacts on the order of ten cones. Although somewhat uncertain, the size, shape, and degree of overlap of the fields covered by third‐row cells are probably not very different from those of first‐ and second‐row cells. The vertical sequence of horizontal cells which contact rods or cones in dogfish is inverted from that in teleosts.
The ascending fiber projections from the principal sensory trigeminal nucleus in the rat
Authors: Smith Ronald L.
Published: January 2005

Persisting reports of uncrossed secondary trigeminothalamic pathways originating from the principal sensory trigeminal nucleus (PrV) are based mainly on data obtained from surgically induced lesions analyzed by methods other than reduced silver impregnation techniques. After complete stereotaxic or direct surgical lesions of PrV, degenerating fibers proceed ventrally and rostrally from the nucleus and cross the midline in the rostral pons, completing their decussation caudal to nucleus interpeduncularis. These fibers form a large trigeminal lemniscus that ascends through the midbrain dorsomedial to the smaller medial lemniscus. PrV fibers terminate in the posterior thalamic nucleus and throughout the medial two‐thirds of the ventrobasal thalamic complex (VBm) contralateral to the side of the lesion. Connections with the ventral part of zona incerta were also found similar to those reported for the medial lemniscus.

Another fiber system proceeds dorsad from the parvicellular reticular formation in the PrV region and terminates on cells of the ipsi‐and contralateral motor trigeminal nuclei and the adjacent contralateral parvicellular reticular formation. Differential lesions indicate that these “intertrigeminal” commissural connections arise chiefly from the parvicellular reticular formation that lies between PrV and the motor trigeminal nucleus.

These experiments, which also included selective lesions of dorsal and rostral portions of PrV, failed to produce any evidence supporting the existence of an uncrossed principal sensory trigeminothalamic pathway in the rat. While selective, ventral zona incerta PrV connections can be demonstrated, no PrV intralaminar projections appear to exist. Initial findings show that comparable fully decussated PrV–VBm connections also exist in the guinea pig but that some ipsilaterally ascending fibers occur in monkeys (Smith, '72). These and other recent data demonstrate that phyletic neural variations exist in the PrV‐thalamic projections in various mammalian species.