Neuropeptide gene expression and neural activity: Assessing a working hypothesis in nucleus caudalis and dorsal horn neurons expressing preproenkephalin and preprodynorphin

1. The working hypothesis that neuropeptide gene expression in a neuron is an indicator of that neuron's physiological activity is discussed. 2. Representative examples from the literature are presented to support the hypothesis. 3. Further, we discuss the regulation of expression of two opioid peptides, preproenkephalin and preprodynorphin, in laminae I and II of the spinal cord and in nucleus caudalis of the trigeminal nuclear complex, where they may play a role in pain modulation. 4. The expression of the opioid peptide genes can be induced by both painful and nonnoxious stimuli in neurons in time-dependent and sensory-specific fashions.     

Stimulation of the Uptake of Sorbitol into Vacuoles from Apple Fruit Flesh by Abscisic Add and into Protoplasts by Indoleacetic Acid

The uptake of sorbitol into vacuoles from immature flesh ofapple fruit (Maluspumila Mill, var domestica Schneid.) was facilitatedby 10^–6 M ABA, while such uptake into protoplasts wasnot stimulated. By contrast, the application of 10^–5 MIAA facilitated uptake of sorbitol into protoplasts but didnot significantly into vacuoles. (Received July 17, 1990; Accepted December 25, 1990)     

Chimpanzee predation in the Mahale mountains from August 1979 to May 1982

Fifty-four episodes of predatory behavior of wild chimpanzees were recorded in Mahale, western Tanzania, from August 1979 to May 1982. The chimpanzees most frequently hunt in two seasons, during May, and from August to December. Longer-term fecal analysis indicates that predation frequency is significantly higher in the dry than in the rainy season. The seasonality of predation might be the result of the sum of various ecological factors, at least one of which is the birth season of the prey species. Most of the prey are juvenile blue duiker, bushbuck, bushpig, red colobus, and red-tailed monkeys. Sex difference is recognized in the prey selection and in the hunting method employed. Apparent local difference in the predatory behavior between Mahale and Combe chimpanzees (in Mahale,females hunt more frequently, and blue duiker is the most frequent prey) can be understood in terms of the difference either in the observation methods or in the faunal diversity and density. Other aspects of predatory behavior also are reported.     

Demographic study of a large-sized unit-group of chimpanzees in the mahale mountains,Tanzania: A preliminary report

Long-term demographic observations on a large-sized unit-group of chimpanzees in the Mahale Mountains, Tanzania, are summarized. The unit-group, the M group, contains over 100 individuals, which makes it the largest unit-group ever reported. The age-sex composition, natality, mortality and transfers of the M group are analyzed. An attempt is made to illustrate an age-sex pyramid of the group by estimating the ages of all the individuals in the group. The results reveal that: (1) the mortality rate of the male infants within 1 year almost doubled that of female infant; (2) adult male to adult female ratio of the M group is considerably higher than any other unit-groups elsewhere; and (3) the M group contains a relatively large number of old animals over 40 years of age, suggesting that the longevity of wild chimpanzees might be greater than estimated so far.     

Gas chromatographic determination of the hypoglycaemic agent gliclazide in plasma

A gas chromatographic method has been developed that permits the accurate and specific determination of the hypoglycaemic agent gliclazide in plasma. Gliclazide is extracted with chloroform and, after clean-up, derivatized with diazomethane followed by heptafluorobutyric anhydride to form N-methyl-N′-heptafluorobutyrylgliclazide, which is assayed on a gas chromatograph equipped with a flame ionization detector, an electron-capture detector or a nitrogen—phosphorus sensitive detector.Accurate determinations are possible with flame ionization detection over a concentration range of 1–15 μg/ml of gliclazide in plasma with a relative standard deviation of 5.2%. The minimum detectable concentration with electron-capture detection is 0.02 μg per sample. Plasma levels of gliclazide in dogs following single oral administration (40 mg per dog) have also been determined.     

Hydrogen exchange kinetics of nucleic acids: Double and triple helices with Hoogsteen-type basepairs

The kinetics of hydrogen-tritium exchange reaction have been followed by a Sephadex technique of a double-helical poly(ribo-2-methylthio-adenylic acid)·poly(ribouridylic acid) complex with the Hoogsteen-type basepair. Only one hydrogen in every 2-methylthio-adenine·uracil basepair has been found to exchange at a measurably slow rate, 0.023 s^?1 (at 0°C), which is, however, much greater than that for a double-helix with the Watson-Crick type A·U pair. The kinetics of hydrogen-tritium exchange were also examined by triple-helical poly(rU)·poly(rA)·poly(rU) which involves both the Watson-Crick and Hoogsteen basepairings. Here, three hydrogens in every U·A·U base triplet have been found to exchange at a relatively slow rate, 0.0116 s^?1 (at 0°C). The kinetics of hydrogen-deuterium exchange reactions of these polynucleotide helices have also been followed by a stopped-flow ultraviolet absorption spectrophotometry at various temperatures. On the basis of these experimental results, the mechanism of the hydrogen exchange reactions in these helical polynucleotides was discussed. In the triple helix, the rate-determining process of the slow exchange of the three (one uracil-imide and two adenine-amino) hydrogens is considered to be the opening of the Watson-Crick part of the U·A·U triplet. This opening is considered to take place only after the opening of the Hoogsteen part of the triplet.     

Effects of acorn masting on population dynamics of three forest-dwelling rodent species in Hokkaido,Japan

The effects of the abundance of acorns of the oak, Quercus crispula, on the population dynamics of three rodent species (Apodemus speciosus, A. argenteus, and Clethrionomys rufocanus) were analyzed using time series data (1992–2006). The data were obtained in a forest in northern Hokkaido, Japan, by live trapping rodents and directly counting acorns on the ground. Apodemus speciosus generally increased in abundance following acorn masting. However, the clear effect of acorn abundance was not detected for the other two rodent species. Acorns of Q. crispula contain tannins, which potentially have detrimental effects on herbivores. Apodemus speciosus may reduce the damage caused by acorn tannins with tannin-binding salivary proteins and tannase-producing bacteria, whereas such physiological tolerance to tannins is not known in the other two rodent species. The differences in the effects of acorns between the three species may be due to differences in their physiological tolerance to tannins.     

Energy Coupled Transport of Sorbitol and Other Sugars into the Protoplast Isolated from Apple Fruit Flesh

The uptake kinetics of sorbitol, sucrose, glucose and fructoseacross the plasma membrane using protoplasts isolated from applefruit flesh (Malus pumila Mill. var. domestica Schneid.) wasinvestigated. When sorbitol was taken up into the cell, PCMBS-sensitivesaturable transport was distinguishable from the diffusive transport.At a low sorbitol concentration, the saturable transport systemaccounted for more than 50% of the total uptake, whereas ata high concentration the diffusive transport system was moredominant. The saturable transport was suggested be a carrier-mediatedtransport system coupled with ATP because the system was inhibitedCCCP or orthovanadate. The K_m value for sorbitol was computedto be 3.6mM. A carrier-mediated transport system coupled withATP was also observed for glucose and fructose with correspondingK_m values of 5.0 and 2.5 mM. However, no saturable transportfor sucrose was observed over a range of 0.1 to 10 mM sucroseconcentration. The relationship among these sugar transportsystems across the plasma membrane, apoplastic unloading, andsugar accumulation vacuoles are discussed. ¹Present address: Laboratory of Horticulture, Faculty of Agriculture,Nagoya University, Chikusa, Nagoya 464, Japan. (Received April 8, 1988; Accepted June 8, 1988)     

2-Ketogluconate Reductase Inhibition by Oxalate

The active site of α-glucosidase from Mucor javanicus IFO 4570 was investigated by kinetic studies. Competition between maltose and soluble starch, and linearity of Lineweaver-Burk plots for the mixed substrates were observed. The dependence of the apparent maximum velocities agreed with those predicted for a single active site mechanism. These results suggest that the enzyme hydrolyzes maltose and soluble starch at a single active site.