Nucleus In Man Research Articles

Quantitative and cytometric analysis of the ventral cochlear nucleus in man

A systematic quantitative and cytometric study of the ventral cochlear nucleus has been performed on 3 groups of histologically normal brains, ranging in age from 20 weeks of gestation to adult life. Serial sections, 20 μm in thickness, through the length of the nucleus were obtained from paraffin-embedded blocks of the ponto-medullary junction. Every 10th section was analyzed with a Cambridge Imanco quantimet 720 Image Analyzing system. The surface area of the nucleus was determined on each slide. Cells showing neuronal characteristics were individually counted and classified into 18 pre-determined cell size classes. The raw total number of cells was then corrected for periodicity and split cell error. The total volume of the nucleus and cell packing density were estimated. The mean total number of neurons was 26,098 in premature, 31,802 in full term and 30,440 in adult cases. There was no significant difference among these values. The mean volume of the nucleus was 1.32 mm 3 in premature, 3.84 in full term and 5.43 in adult cases. Positive correlation coefficients were found comparing volume versus age. A negative correlation coefficient was detected comparing cell packing density versus age from the full term period to adult life. A significant increase in the number of cells in the largest cell classes was also found with increasing age. The mean neuronal diameter did not change significantly between premature and full term cases but was significantly different between full term and adult cases. These findings are discussed and compared to already reported quantitative studies of the ventral cochlear nucleus in man, which involved manual counting techniques.

The cochlear nuclei in man

The human cochlear nuclei are composed of a ventral and a dorsal nucleus which are similar, though not identical, in their cytoarchitecture to those of other mammals. The ventral cochlear nucleus (VCN) consists of a rostral area of spherical cells, a central area of multipolar and globular cells, a posterior area of octopus cells, and laterodorsal cap of small neurons. The interareal boundaries are less distinct in man than in the cat. The central region of multipolar cells and the cap area of small cells constitute the bulk of the human VCN. The spherical, globular, and octopus cells appear relatively less numerous in man than in other mammals. The dorsal cochlear nucleus (DCN) in man is relatively large, but lacks the typical stratification seen in other mammals, with only vestiges of the granular and molecular layers remaining. Virtually the entire DCN consists of an area of cochlear fiber neuropil containing pyramidal cells, small neurons, and occasional giant cells. The pyramidal cells have lost their typical radial orientation and lie scattered within the cochlear neuropil. Thus the entire human DCN may be equivalent to layers 2 and 3 of this nucleus in other mammals. In spite of the relatively large DCN, the acoustic striae appear small. This is in contrast to the large trapezoid body leaving the VCN. Intrinsic and descending fiber pathways to the cochlear nuclei are not clearly defined and may be less prominent in man than in the cat.

Second National Symposium on Groundwater Quality Set

The U.S. Environmental Protection Agency and the National Water Well Association are sponsoring a Second National Conference on Groundwater Quality to be held September 25–27, 1974, at the Holiday Inn in downtown Denver, Colorado.The purpose of the meeting is to bring together a nucleus of men, methods, and ideas capable of yielding solutions to problems that must be solved to ensure the protection and restoration of the quality of the nation's groundwater resources. Development of these resources is expected to double and perhaps triple in the coming decade.

Volume of the ventral cochlear nucleus in man: its relationship to neuronal population and age.

Volume of the ventral cochlear nucleus in man: its relationship to neuronal population and age.

Evoked cortical responses following stimulation of the thalamic VL nucleus in man.

Evoked cortical responses following stimulation of the thalamic VL nucleus in man.

Influence of incidence angle of monoenergetic neutrons on dose equivalent distribution for recoil nuclei in man's phantom.

Influence of incidence angle of monoenergetic neutrons on dose equivalent distribution for recoil nuclei in man's phantom.

A somatotopical pattern in the human lateral vestibular nucleus.

IN RECENT years, the vestibular apparatus and its central connections have attracted much interest by anatomists, physiologists, and clinicians. In part, it appears due to the importance of vestibular function in manned space flights. Most of the new knowledge has come from research on animals, especially as regards the vestibular nuclei, their connections and functions. Although it appears to be generally true that in principle conditions are similar in man and the experimental animals employed, on many points actual proof is still lacking. There are only few reports on the connections of the vestibular nuclei in man, and most of them are rather old. This justifies the publication of the present case study, undertaken in order to investigate a special question: Is the vestibulospinal projection in man somatotopically organized as it has been shown to be in the cat? The minute analysis of the vestibular nuclei in the cat,

Functions of cell groups in oculomotor nucleus of man

Functions of cell groups in oculomotor nucleus of man

Neuropathology of the Ventral Cochlear Nucleus in Man as Seen in Neuronal Population Estimates

Neuropathology of the Ventral Cochlear Nucleus in Man as Seen in Neuronal Population Estimates

Bilateral, Three Negative, Cortical Evoked Potentials after Unilateral Stimulation of the Thalamic VL Nucleus in Man

Bilateral, Three Negative, Cortical Evoked Potentials after Unilateral Stimulation of the Thalamic VL Nucleus in Man

Effects of stimulating or destroying the deep cerebellar regions in man.

ITUATED deep within the paramedian region of the cerebellum lies a constellation of nuclei that relay cerebellar influences throughout the central nervous system. The dentate, which is the largest of these nuclei in man, was first described in 1685 by VieussenY 9 It relays chiefly the efferent outflow from the lateral hemispheric area of the cerebellum, exerting its influence on the tone and movement of the ipsilateral limbs. 1,~,~4,25 Experimental dentate lesions result in hypotonia, dysmetria, and, in some cases, tremor. 1,~,24 Recently, neurosurgeons have attempted to ablate the dentate in persons with extreme hypertonia and involuntary movements. We have developed stereotaxic coordinates for the cerebellar nuclei in order to explore the paramedian cerebellar regions by electrical stimulation with a view of assessing the therapeutic possibilities of cerebellar nuclear lesions. 26 This report concerns the effects of electrical stimulation and high frequency lesions in the regions of paramedian cerebellar structures. Method

A quantitative analysis of the normal neuron population of the hypothalamic magnocellular nuclei in man and of their projections to the neurohypophysis.

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 mm3 and, 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 hypophysial stalk.

Quantitative data on the inferior olivary nucleus in man, cat and vampire bat.

AbstractA quantitative study of the inferior olivary nucleus in single specimens of man, cat and vampire bat has been made. The number of cells in the human is about 908,680 which is about one‐fifteenth the number of Purkinje cells thought by others to be present in the human cerebellum.The estimated figure in the cat is about 140,520 while in the vampire it is 26,644. The relation of these figures to the total number of Purkinje cells in the last two species is still to be determined. The neuron density is highest in the vampire where the volume of the cell bodies represents one‐eighth the total volume of the nucleus while in the cat the comparable ratio is one‐sixteenth, and in the human one‐twenty‐fifth. This reflects the richer neuropils of afferent connections and dendrites in the more highly developed species.Unsolved problems and discrepancies concerning the number of olivary cells and Purkinje cells in the light of present concepts of the olivary origin of climbing fibers are discussed and areas of future study are suggested.

Variable size of the septal nuclei in man.

Variable size of the septal nuclei in man.

Depth electrographic studies on the caudate nucleus in man

1. 1. During wakefulness, spontaneous electrical activity from the caudate nucleus in man was characterized by an alpha-like rhythm interrupted by bursts of slow and sharp waves. Decreased voltage and marked slowing were observed during light sleep. 2. 2. Somatic and visual stimulation evoked long latency complex and multiphasic activity in the caudate nucleus. 3. 3. “Spindles” or “recruiting” at the scalp could not be induced following electrical stimulation of the caudate nucleus. 4. 4. Behavioral effects of caudate stimulation consisted of interference with repetitive movements and production of autonomic responses when high current intensities were employed. These effects are attributed to current spread to the internal capsule and possibly the septal area.

Quantitative determinations of neurons and glial cells in the nuclei of the facial and vestibular nerves in man, monkey and dog.

AbstractThe number of Neurons and the Neuronal and glial density per volume of the facial and the vestibural nuclei in two brain stems on each side in man, monkey and dog were counted. The average number of Neurons in the facial nucleus in man (12,500) is greater than in the monkey (4,600), but lower than in the dog (15,800). On the contrary, in the vestibural nuclei the total number of Neurons in man (245,00) is greater than in the monkey (143,000) as in the dog (134,000). The Neuronal density varies considerably in different nucei and different species of animals. At the same time, the glial density is much more even. In all the nuclei the glial density is highest in the dog, lower in the monkey and still lower in man.

Allan Philip Colburn—the years with du pont

IT WAS a fortunate circumstance that brought Allan Colburn to the Du Pont Experimental Station, 23 September 1929. A research group in chemical engineering had just been organized, under the far-sighted administration of C. M. A. Stine, Chemical Director, and A. P. Tanberg, Director of the Experimental Station, paralleling and extending the groups set up to undertake fundamental research, not tied to immediate commercial objectives, in polymer chemistry, headed by W. H. Carothers, in colloid chemistry, and in catalysis. The chemical engineering group, which I had the privilege of heading, was built around the nucleus of men who had been working on improvements in the manufacture of acids, but Colburn was one of the very first additions made to prosecute the fundamental research objectives. He had conducted at the University of Wisconsin, with 0. A. Hougen, a noteworthy investigation in the field of heat transfer [19]. It was this, indeed, which brought him to the attention of the Du Pont Company, and it was natural, therefore, that heat transfer was the topic assigned to him for study. The objectives of the research group in chemical engineering were to find out what was known about the several unit operations, with the aim of making information available to the people engaged in the design of plants that would lead to the specification of equipment and methods of operation that would be the most economical and give the greatest assurance of satisfactory performance. Colburn fell in readily with these objectives. He attacked his assignments with unfeigned zeal, and found, I feel sure, real satisfaction in carrying them out. The chemical engineering research group, with a unified central aim but with the members each responsible for separate topics, provided a congenial atmosphere, refreshed and stimulated by the frequent visits of W. H. McAdams as a consultant. Colburn’s first publication from the Experimental Station was in a sense an extension of his Wisconsin thesis [q. His work there was directed towards improving the design of dehumidifying gas coolers used in the manufacture of city gas. It is cited here as establishing the early date of his putting forward of the “Colburn analogy”, as it might better be called, even though not in the exact form in which it has come to be known. In this paper Colburn extended the idea he lirst developed in the second part of his earlier publication [18] ; namely, that the incorporation of the ratio of the molecular diffusivity to the momentum diffusivity (kinematic viscosity) should accomplish for mass transfer in conduits what the Prandtl and Taylor modifications of the Reynolds analogy did for heat transfer, with the function of the Prandtl number called for to conform to the velocity distribution in turbulent flow. Colburn was able to show that the corresponding expression did show agreement with the Wisconsin data on dehumidification, as well as with data obtained some years before at the Experimental Station by C. H. Greenewalt on the drying of air with sulfuric acid in a falling film column. The group of three papers published in 1931 exemplifies Colburn’s special talents [2, 7, 201. The chemical engineering group was, among other things, looking into the possibility of designing an integral converter-heat exchanger for the catalytic conversion of SO2 to SOs, and Colburn undertook to carry out tests to determine the heat-transfer coefficients we could

SLOW POTENTIAL WAVES PRODUCED IN THE CUNEATE NUCLEUS BY CUTANEOUS VOLLEYS AND BY CORTICAL STIMULATION.

SLOW POTENTIAL WAVES PRODUCED IN THE CUNEATE NUCLEUS BY CUTANEOUS VOLLEYS AND BY CORTICAL STIMULATION.

Limbic nuclei of thalamus and connections of limbic cortex. IV. Thalamocortical projection of the ventral anterior nucleus in man.

Introduction In an earlier paper in this program of studies on the organization of thalamo-cortical projections evidence has been presented that the lateral dorsal nucleus represents a caudal member of the group of nuclei which project upon the limbic cortex—the limbic nuclei. 22 This interpretation of the position and main projection of the lateral dorsal nucleus is not in accord with the views in the extant literature. 9,11,12,18,21 That the lateral dorsal nucleus does project to cortex is apparent from experimental studies in the monkey 1,14,21 and pathological material in the human. 3,12,13,17 In the recorded human cases the cortical lesions have been quite extensive. From such material only the most inferential conclusions can be drawn with regard to the cortical projection field of the lateral dorsal nucleus. A human brain in the collection of the Warren Anatomical Museum (NP Series MU-5-57) with a circumscribed old infarct involving the praecallosal

Biosynthesis of C19 steroids from 4-14C-cholesterol and 7-3H-pregnenolone in vivo: consideration of new pathways.

ABSTRACT 3H and 14C specific activities of dehydroepiandrosterone, androsterone, 3α-hydroxy-5β-androstan-17-one and 3α-hydroxy-5α-androst-16-ene (without dilution) have been determined following a single intravenous injection of 4-14C-cholesterol and 7α-3H-pregnenolone to a virilized woman with an adrenal adenoma and massive dehydroepiandrosterone excretion. Assuming a one compartment model, or a two compartment model in which the injected radioactivity enters the compartment in which the precursor is secreted exclusively, a new pathway by which dehydroepiandrosterone is formed from cholesterol not through pregnenolone and possibly by cleavage of the side chain C-17 and C-20 is indicated. Analysis of the data by a model in which pregnenolone is secreted into two separate compartments in which progesterone and dehydroepiandrosterone are made, respectively, would explain the findings without necessitating the assumption of a new pathway. 3α-Hydroxy-5α-androst-16-ene was isolated from urine following incubation with β-glucuronidase and partition chromatography on celite suggesting that this steroid is a genuine natural product as surmised by Prelog & Ruzicka (1944) and Brooksbank & Haslewood (1950). 2-14C-Mevalonate was shown to give rise to C19 steroids which is the first in vivo demonstration that mevalonic acid is a precursor of the steroid nucleus in man.