Interneuronal mechanisms for learning-induced switch in a sensory response that anticipates changes in behavioral outcomes

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Calcium ion uptake,somatotropin release,and fine structure of somatotrophs in cultures of the rat anterior pituitary upon the action of an oligopeptide (Boc-Gln-Leu-Lysinal)

Summary Cultured cells from the anterior pituitary glands of adult rats were treated with the tripeptide aldehyde proteinase inhibitor, Boc-Gln-Leu-Lys-H. The oligopeptide had a profound relesing effect on growth hormone, whereas the prolactin release remained unchanged at 10^–3 mol/l drug concentration after an incubation for 2 h. In the presence of the oligopeptide a time- and dose-dependent calcium influx into cultured cells has been shown which was proved to be almost completely antagonized with magnesium ions but not with Nifedipine. In addition, radioactive calcium ions could be detected in a number of cells by light microscopic autoradiography when cultures were treated with Boc-Gln-Leu-Lys-H for short periods. The selective Gel action of the oligopeptide on growth hormone producing cells has been demonstrated also in fine structural investigations: multigranular and single exocytotic profiles have been observed. Accordingly, we have postulated that Boc-Gln-Leu-Lysinal mimics the effects of the known ionophores. Its mode of action needs, however, further studies especially on isolated somatotrophs.     

Conditional DNA repair mutants enable highly precise genome engineering

Oligonucleotide-mediated multiplex genome engineering is an important tool for bacterial genome editing. The efficient application of this technique requires the inactivation of the endogenous methyl-directed mismatch repair system that in turn leads to a drastically elevated genomic mutation rate and the consequent accumulation of undesired off-target mutations. Here, we present a novel strategy for mismatch repair evasion using temperature-sensitive DNA repair mutants and temporal inactivation of the mismatch repair protein complex in Escherichia coli. Our method relies on the transient suppression of DNA repair during mismatch carrying oligonucleotide integration. Using temperature-sensitive control of methyl-directed mismatch repair protein activity during multiplex genome engineering, we reduced the number of off-target mutations by 85%, concurrently maintaining highly efficient and unbiased allelic replacement.     

Neutron scattering in photosynthesis research: recent advances and perspectives for testing crop plants

Photosynthesis Research - The photosynthetic performance of crop plants under a variety of environmental factors and stress conditions, at the fundamental level, depends largely on the organization...     

Spectral Characteristics of Phase Sensitivity and Discharge Rate of Neurons in the Ascending Tectofugal Visual System

Drifting gratings can modulate the activity of visual neurons at the temporal frequency of the stimulus. In order to characterize the temporal frequency modulation in the cat’s ascending tectofugal visual system, we recorded the activity of single neurons in the superior colliculus, the suprageniculate nucleus, and the anterior ectosylvian cortex during visual stimulation with drifting sine-wave gratings. In response to such stimuli, neurons in each structure showed an increase in firing rate and/or oscillatory modulated firing at the temporal frequency of the stimulus (phase sensitivity). To obtain a more complete characterization of the neural responses in spatiotemporal frequency domain, we analyzed the mean firing rate and the strength of the oscillatory modulations measured by the standardized Fourier component of the response at the temporal frequency of the stimulus. We show that the spatiotemporal stimulus parameters that elicit maximal oscillations often differ from those that elicit a maximal discharge rate. Furthermore, the temporal modulation and discharge-rate spectral receptive fields often do not overlap, suggesting that the detection range for visual stimuli provided jointly by modulated and unmodulated response components is larger than the range provided by a one response component.     

Activity-induced skeletal markers in historical anthropological material

A new research way of palaeopathology has recently opened: it concerns the study of the impact of the human activities on the skeleton and the reconstitution of these activities. Being interested essentially in the activity-induced skeletal markers, we carried out this study on 354 human skeletal remains. The Hungarian series represents a larger sample (263 skeletons from the 10th century; collections of the Department of Anthropology, József Attila University, Szeged, Hungary). We considered also as comparison series a collection of 91 skeletons dating from the Late Antiquity (4th century A.D.) from Provence (France), stored in the collections of the Centre Archéologique du Var (Toulon, France). The present work is based on the results of a general palaeopathological analysis with a particular attention to the possible activity-linked microtraumatic lesions. Articular and periarticular markers of activity were detected as secondary degenerative joint diseases and mechanical enthesopathies. In spite of the high rate of non-specific cases, the alterations reveal several possible activities, historically and archaeologically well documented as riding on horse-back in the Hungarian series. The sexual inegality in the distribution of the macrotraumatic lesions (male predominance of the fractures and sprains in the Hungarian series) reveals also some information about the activities of the ancient Hungarians.