Chromosomal effect in vivo of exposure to lysergic acid diethylamide

Chromosome studies of persons exposed to lysergic acid diethylamide, either self-administered or received during medical therapy, failed to demonstrate significant chromosomal damage.     

Leukocytes of humans exposed to lysergic acid diethylamide: lack of chromosomal damage

Leukocyte cultures from eight human subjects who had had recent exposure to large doses of lysergic acid diethylamide were examined for chromosome abnormalities. The number of abnormalities was not significantly greater than that in control cultures.     

Congenital malformations induced by mescaline, lysergic acid diethylamide, and bromolysergic acid in the hamster

Malformations of the brain, spinal cord, liver, and other viscera; body edema; and localized hemorrhages were found in fetal hamsters from mothers injected subcutaneously with a single dose of mescaline, lysergic acid diethylamide, or 2-bromo-D lysergic acid diethylamide on the 8th day of pregnancy. In addition, all three drugs produced an increase in the percentages of small fetuses per litter, of resorptions, and of fetal mortality.     

Lysergic acid diethylamide: role in conversion of plasma tryptophan to brain serotonin (5-hydroxytryptamine)

Injections of D-lysergic acid diethylamide decrease the turnover rate of 5-hydroxytryptamine of rat brain, as measured from the conversion of (14)C-tryptophan into (14)C-5-hydroxytryptamine. The 2-bromolysergic acid diethylamide given in doses fivefold greater than those of lysergic acid diethylamide fails to change the rate of (14)C-tryptophan conversion into (14)C-5-hydroxytryptamine. The effect of D-lysergic acid diethylamide is discussed with regard to its action on brain serotonergic neurons and its psychotomimetic effects.     

Nuclear localization of histamine in neonatal rat brain

The concentration of histamine in the brains of neonatal rats is considerably higher than that in adults. Subcellular fractionation studies revealed that about 90 percent of the histamine content of neonatal rat brain is confined to the crude nuclear fraction obtained by differential fractionation. Purified nuclei prepared from these fractions retained 90 percent of their histamine content. The nuclear localization of histamine in the brains of neonatal rats suggests a function for histamine in modulating the growth processes of the neonatal brain.     

Quantitative autoradiography of [3H]muscimol binding in rat brain

A simple quantitative autoradiographic technique for the study of neurotransmitter receptors that includes the use of a tritium-sensitive film permits saturation, kinetic, and competition studies of brain samples as small as 0.01 cubic millimeter. This technique was used to study [3H]muscimol binding in rat brain. Unilateral gamma-aminobutyric acid receptor supersensitivity was observed in the substantia nigra pars reticulata after production of localized lesions of the ipsilateral corpus striatum.     

Lysergic acid diethylamide: sensitive neuronal units in the midbrain raphe

Units in areas of the midbrain rich in neurons containing serotonin respond to parenteral injections of d-lysergic acid diethylamide by a reversible cessation of spontaneous activity. The dose required is at or below threshold for gross behavioral effects. An inhibition of neurons containing serotonin after administration of d-lysergic acid diethylamide could account for the decreased metabolism of serotonin produced by this drug.     

Corticotropin-releasing factor receptors in rat forebrain: autoradiographic identification

Corticotropin-releasing factor (CRF) receptors were identified in rat forebrain by autoradiography with an iodine-125-labeled analog of ovine CRF substituted with norleucine and tyrosine at amino acid residues 21 and 32, respectively. High-affinity receptors for CRF were found in discrete areas of rat forebrain, including laminae I and IV of the neocortex, the external layer of the medium eminence, the lateral nucleus of the amygdala, and the striatum. These results are consistent with earlier findings on the immunohistochemical distribution of CRF and suggest that endogenous CRF has a physiological role in regulating activity of the central nervous system.     

Testosterone concentration in the male chick brain: an autoradiographic survey

Differential uptake of [(3)H]testosterone in male chick brain was found in periventricular areas of preoptic-hypothalamic continuum. Concentration of silver grains for all decapitation periods was especially high in the medial preoptic area, particularly the nucleus praeopticus paraventricularis magnocellularis. Distribution of testosterone-sensitive cells is in agreement with studies showing neuroanatomical control of reproductive behavior by the avian forebrain.     

Immunohistochemical localization in the rat brain of the precursor for thyrotropin-releasing hormone

A rabbit antiserum to a peptide sequence present in the precursor for thyrotropin-releasing hormone (proTRH), deduced from cloned amphibian-skin complementary DNA, was raised by immunization with the synthetic decapeptide Cys-Lys-Arg-Gln-His-Pro-Gly-Lys-Arg-Cys (proTRH-SH). Immunohistochemical studies on rat brain tissue showed staining of neuronal perikarya in the parvicellular division of the paraventricular nucleus of the hypothalamus and the raphe complex of the medulla, identical to that already described for thyrotropin-releasing hormone (TRH). Immunostaining was abolished by preincubation with proTRH-SH (10(-6)M) but not TRH (10(-5)M). Both TRH precursor and TRH were located in neurons of the paraventricular nucleus. However, in contrast to the findings for TRH, no staining was observed in axon terminals of the median eminence. These results suggest that a TRH precursor analogous to that reported in frog skin is present in the rat brain and that TRH in the mammalian central nervous system is a product of ribosomal biosynthesis.     

Hydrocalcite (CaCO3 * H2O) and Nesquehonite (MgCO3 * 3H2O) in Carbonate Scales

Hydrocalcite (CaCO(3) * H(2)O) with exactly one molecule of hydrate water is the main component of carbonate scales deposited from cold water in contact with air. When the magnesium content of the water is high, the hydrocalcite occurs together with MgCO(3) * 3H(2)O (nesquehonite). From the conditions under which hydrocalcite is transformed into calcite and aragonite, it appears that in some cases aragonite in nature may be formed by way of an intermediary of CaCO(3) * H(2)O.     

Pentapeptide (pepstatin) inhibition of brain acid proteinase

The pentapeptide pepstatin obtained from culture filtrates of actinomycetes completely inhibited brain acid proteinase (cathepsin D) at exceedingly low concentrations. Among the brain enzymes tested, the effect is specific for acid proteinase because addition of 1000-fold higher concentrations was without effect on neutral proteinase, aminopeptidase, and arylamidases. Pepstatin also inhibits pepsin as tested with hemoglobin or with N-acetylphenylalanyl-L-diiodotyrosine as substrate. Pepstatin must be regarded as the most powerful agent yet described that inhibits intracellular acidic proteolytic enzyme in brain.     

Quinolinic acid: an endogenous metabolite that produces axon-sparing lesions in rat brain

A current hypothesis links the neuroexcitatory properties of certain acidic amino acids to their ability to cause selective neuronal lesions. Intracerebral injection of the neuroexcitatory tryptophan metabolite, quinolinic acid, has behavioral, neurochemical, and neuropathological consequences reminiscent of those of exogenous excitotoxins, such as kainic and ibotenic acids. Its qualities as a neurotoxic agent suggest that quinolinic acid should be considered as a possible pathogenic factor in neurodegenerative disorders.     

Autoradiographic localization of radioactivity in rat brain after injection of tritiated sex hormones

Radioactivity was found in cell bodies of neurons and glial cells throughout brains of male and female rats that had been injected with either testosterone-H(3) or estradiol-H(3). Uptake by limbic and hypothalamic structures was higher and longer lasting than that in nonlimbic structures. In all brains, the preoptic area, prepiriform cortex, olfactory tubercle, and septum had particularly high, long-lasting uptake of both hormones.     

Ribonucleic acid biosynthesis in adult and infant rat brain in vitro

The rate of biosynthesis of ribonucleic acid (as judged by the rate of incorporation of uridine into ribonucleic acid) in infant and adullt rat brain cortex slices, incubated (aerobically in tile presenice of various substrates, is directly proportionial to the adenosine triphosphate concentration. This suggests that the adenosine triphosphate concentration is one of the factors involved in the control of ribonucleic acid biosynthesis in infant and adult rat brain. Acetoacetate or beta-hydroxybutyrate is about 70 percent as effective as glucose, with both infant and adult brain, for the promotion of ribonucleic acid biosynthesis. but they are considerably mnore effective than succinate in infant brain than in adult brain.     

Alpha-hydroxy acid oxidase: localization in renal microbodies

Differential and density equilibrium centrifugation have established the presence of alpha-hydroxy acid oxidase in microbodies of the kidney of the rat. The enzyme has been demonstrated in cells of the distal convoluted tubule by a microscopic cytochemical method. This enzyme, like certain others in microbodies, produces hydrogen peroxide.     

Language production: electroencephalographic localization in the normal human brain

Slow negative potentials, which are at a maximum over Broca's area in the left hemisphere, were recorded when normnal subjects spontaneously produced polysyllabic words. Bilaterally symmetrical potentials were seen with analogous, nonspeech control gestures. These potentials began up to 1 second before word or gesture articulation. These results are the first demonstration of localization of language production in normal human brain.