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C H Anderson

Publications and source records attributed to C H Anderson.

36 records · Page 2Linked to original sources
PubMed1986

Comparison of the effects of muscarine and vasopressin on inositol phospholipid metabolism in the superior cervical ganglion of the rat.

Both muscarine and vasopressin have been shown previously to increase the accumulation [3H]inositol phosphates in superior cervical ganglia in which the phospholipids were labeled with [3H] inositol. In this study, we have compared the effects of muscarine and of vasopressin on phospholipid metabolism in the ganglion. The effects of these agents on [3H]inositol phosphate accumulation are additive. The response to muscarine levels off after approximately 10 min, whereas the response to vasopressin increases for at least 30 min. The incorporation of [3H]inositol into phospholipids is enhanced in decentralized ganglia and in ganglia maintained in organ culture compared to freshly isolated ganglia. These treatments appear to potentiate the effect of muscarine on [3H]inositol phosphate accumulation, but do not affect the response of the ganglia to vasopressin. Muscarine and vasopressin also increase the incorporation of [3H]inositol into phospholipids in the ganglion. Autoradiographic techniques were used to localize the inositol-containing phospholipids in the ganglion. Muscarine increases phospholipid labeling primarily in the cell bodies of the principal ganglionic neurons, whereas vasopressin increases phospholipid labeling primarily in the neuropil. These data are consistent with the hypothesis that muscarine and vasopressin stimulate the hydrolysis of different pools of ganglionic phospholipids.

Animals↗
PubMed1985

Mechanistic flexibility in the reduction of copper(II) complexes of aliphatic polyamines by mercapto amino acids.

The reactions of copper(II)-aliphatic polyamine complexes with cysteine, cysteine methyl ester, penicillamine, and glutathione have been investigated, with the goal of understanding the relationship between RS- -Cu(II) adduct structure and preferred redox decay pathway. Considerable mechanistic flexibility exists within this class of mercapto amino acid oxidations, as changes in the rate law could be induced by modest variations in reductant concentration (at fixed [Cu(II)]0), pH, and the structure of the redox partners. With excess cysteine present at 25 degrees C, pH 5.0, I = 0.2 M (NaOAc), decay of 1:1 cys-S- -Cu(II) transient adducts was found to be first order in both cys-SH and transient. Second-order rate constants characteristic of Cu(dien)2+(6.1 X 10(3) M-1 sec-1), Cu(Me5dien)2+ (2.7 X 10(3) M-1 sec-1), Cu(en)22+ (2.1 X 10(3) M-1 sec-1), and Cu(dien)22+ (4.7 X 10(3) M-1 sec-1) are remarkably similar, considering substantial differences in the composition and geometry of the oxidant first coordination sphere. A mechanism involving attack of cysteine on the coordinated sulfur atom of the transient, giving a disulfide anion radical intermediate, is proposed to account for these results. Moderate reactivity decreases in the cysteine-Cu(dien)2+, Cu(Me5dien)2+ reactions with increasing [H+] (pH 4-6) reflect partial protonation of the polyamine ligands. A very different rate law, second order in the RS- -Cu(II) transient and approximately zeroth order in mercaptan, applies in the pH 5.0 oxidations of cysteine methyl ester, penicillamine, and glutathione by Cu(dien)2+ and Cu(Me5dien)2+. This behavior suggests the intermediacy of di-mu-mercapto-bridged binuclear Cu(II) species, in which a concerted two-electron change yields the disulfide and Cu(I) products. Similar hydroxo-bridged intermediates are proposed to account for the transition from first- to second-order transient dependence in cysteine oxidations by Cu(dien)2+ and Cu(Me5dien)2+ as the pH is increased from 5 to 7. Yet another rate law, second order in transient and first order in cysteine, applies in the pH 5.0 oxidation of cysteine by Cu(Me6tren)2+ (k(25 degrees C) 7.5 X 10(7) M-2 sec-1, I = 0.2M). Steric rigidity of this trigonal bipyramidal oxidant evidently protects the coordinated sulfur atom from attack in a RSSR- -forming pathway. Formation of a coordinated disulfide in the rate-determining step is proposed, coupled with attack of a noncoordinated cysteine molecule on a vacated coordination position to stabilize the (Me6tren)Cu(I) product.

Amino Acids, Sulfur↗
PubMed1984

Visual illusions without low spatial frequencies.

It has been suggested that many geometrical illusions may be caused by the lower spatial frequencies in the Fourier spectra of these images. We have tested this hypothesis by constructing classical illusory figures out of a new dot stimulus, which is free of visible low spatial frequencies. In every case, not only does the illusion persist, but for the Müller-Lyer figures, which were measured quantitatively, the illusion magnitude is not significantly changed. We conclude that geometrical illusions are not primarily a consequence of low spatial frequencies in the illusory figures.

Form Perception↗
PubMed1982

Changes in dendritic spine density in the preoptic area of the female rat at puberty.

Preoptic area (POA) neurons stained by a modification of the Golgi-Kopsch method were studied in developing female rats. Particular attention was focused on dendritic spine densities as they might be altered in relation to the onset of puberty. Neurons in the anterior superior and posterior superior portions of the POA showed an increase in mean spine density at the age of vaginal opening. The increase in dendritic spine density in the posterior inferior quadrant of POA occurred prior to vaginal opening. The entire posterior POA maintained peak levels of spine numbers through 55 days of age, but then exhibited a dramatic drop at 75 days. Thus, modification of the neuropil may well continue at least to this age. The increases in spine densities at vaginal opening for the superior POA quadrants, followed by relatively stable values, appear to implicate these areas in the timing of the onset of puberty.

Animals↗
PubMed1976

Effect of hypophysectomy on estrogen conjugation and on plasma and tissue concentrations of tritium after administration of 3H-estradiol-17beta.

Estradiol-17beta-6,7-3H was injected into ovariectomized (control) and ovariectomized, hypophysectomized (hypox) rats in order to study the binding of estradiol in the brain. Hypophysectomy resulted in a significant increase in the concentration of tritium in the hypothalamus, and preoptic area, as well as cortex, muscle, plasma and liver. However, since the liver was lighter in hypox rats, the total tritium content in the liver was unchanged from controls. Part of the weight reduction in the liver was due to a loss of stainable glycogen, which took place within 24 hours of hypox. The increase in circulating tritiated estradiol after hypox led us to investigate hepatic metabolism of estradiol. In vitro studies on liver slices from control and hypox rats demonstrated a significant reduction in the formation of conjugates of estrogen. Specifically, estradiol glucuronide and estrone sulfate formation were reduced in hypox rats and conversely the unmetabolized estradiol concentration was higher. Hypophysectomy for 24 hours results in a significant decrease in hepatic metabolism of estradiol-17beta.

Animals↗
PubMed1976

Effects of early treatment with antiserum to ovine follicle-stimulating hormone and luteinizing hormone on gonadal development in the rat.

Neonatal rats secrete considerable amounts of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) between 5 and 15 days of age. Antisera to LH and FSH were injected during this 11-day period in an attempt to study the importance of gonadotropins for functional development of the gonads. Autopsies at 15 days of age revealed normal ovarian follicular histology after either antiserum treatment, but antiserum to LH significantly retarded differentiation of interstitial tissue. Uterine weights were increased, and some of the serum samples showed elevated FSH levels following the antiserum treatments. The testes of antiserum-treated rats were heavier at 15 days of age, while accessory sex organ weights were unchanged. Vaginal opening after antiserum treatment was more variable than in controls, but tended to be earlier. The first appearance of penile serum was not significantly changed. Both males and females were fertile as adults. Important limitations to the use of chronic antiserum injections were found in immature rats. The antisera were present for at least 34 days after injection. The ways in which this pool of antiserum might have influenced the results are discussed.

Animals↗
PubMed1975

Localization of cells retaining 3H-estradiol in the forebrain of rabbits.

Ovariectomized rabbits received 3H-estradiol via an ear vein and were killed one hour later. Autoradiograms were prepared and exposed up to six months. Labeled cells, as indicated by many silver grains over the nucleus of a neuron, were found in many nuclei of the brain. Thus, the bed nucleus of the stria terminalis had labeled cell bodies. The stria terminalis leads into the medial preoptic area where great numbers of cells concentrated the estrogen. Farther into the hypothalamus the labeled cells were numerous in the ventromedial and arcurate nuclei. Other locations with labeled cells were the lateral septal nucleus and nucleus accumbens septi, the periventricular preoptic nucleus, anterior hypothalamic nucleus, nucleus supraopticus diffusus, posterior hypothalamic nucleus, and premammillary nucleus. The labeled cells could be followed into the central gray surrounding the aqueduct of Sylvius. The amygdaloid nuclei, and in particular the medial amygdaloid nucleus, had labeled cells as did the most ventral posterior part of the hippocampal cortex. The results are discussed in comparison with those in the rat, and with reference to physiologic data.

Amygdala↗
PubMedDate not supplied

Efferents of the medial preoptic area in the guinea pig: an autoradiographic study.

Medial preoptic axons were traced into the diagonal band of Broca and septum, particularly lateral septum. Other labeled fibers could be followed dorsally from medial preoptic area injections adjacent to the stria medullaris, and in the periventricular fiber system and the stria terminalis and its bed nucleus. The anterior and medial amygdaloid nuclei were labeled by fibers via the stria terminalis and other arching over the optic tract and through the substantia innominata. The lateral habenula was labeled. Labeled periventricular fibers reached the periventricular nucleus of the thalamus. Descending efferents were traced principally below the fornix and in the adjacent lateral hypothalamus to label the anterior hypothalamus, the tuberal nuclei, and median eminence. Axons of the medial preoptic area joined the medial part of the medial forebrain bundle and distributed to the reticular formation and the central gray of the midbrain and pons. A small amount of contralateral connections were described.

Animals↗
PubMedDate not supplied

Efferents from the medial anterior hypothalamic area in the guinea pig.

Medial anterior hypothalamic connections were studied with H3-proline and autoradiography. Most of the axons projected to other hypothalamic nuclei. The major pathways were found ventral medial to the fornix and in the periventricular tract. Substantial projections were apparent in the ventromedial and dorsomedial nuclei with less label in the arcuate nucleus. The dorsal premammillary nuclei were labeled bilaterally, particularly with more caudal injections of anterior hypothalamus. Efferents were evident in the posterior hypothalamus and continued into the central gray of the midbrain. Labeled fibers reached the ventral tegmental area and in the reticular formation were traced only through pons. Rostral projections were to the medial and lateral preoptic areas and ventral lateral septum. The bed nucleus of stria terminals was labeled a very few fibers reached the medial amygdaloid nucleus. The periventricular nucleus of thalamus was labeled.

Animals↗
PubMedDate not supplied

An integrated software suite for surface-based analyses of cerebral cortex.

The authors describe and illustrate an integrated trio of software programs for carrying out surface-based analyses of cerebral cortex. The first component of this trio, SureFit (Surface Reconstruction by Filtering and Intensity Transformations), is used primarily for cortical segmentation, volume visualization, surface generation, and the mapping of functional neuroimaging data onto surfaces. The second component, Caret (Computerized Anatomical Reconstruction and Editing Tool Kit), provides a wide range of surface visualization and analysis options as well as capabilities for surface flattening, surface-based deformation, and other surface manipulations. The third component, SuMS (Surface Management System), is a database and associated user interface for surface-related data. It provides for efficient insertion, searching, and extraction of surface and volume data from the database.

Anatomy, Artistic↗