bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production and characterization of intergeneric somatic hybrids between Moricandia arvensis and Brassica oleracea
Authors: Ishikawa S. , Bang S. W. , Kaneko Y. , Matsuzawa Y. , Röbbelen G. 
Published: June 2003

AbstractSomatic hybrids were produced between Moricandia arvensis (MaMa, 2n= 28) and Brassica oleracea (CC, 2n= 18) through cell fusion and then characterized by analysing their morphology, cytology, DNA constitution, leaf anatomy and seed fertility. Cell fusion was carried out between greenish protoplasts isolated from the mesophyll of M. arvensis and colourless ones from hypocotyls of B. oleracea. Three plants were generated from one shoot via cuttings and acclimatized in vivo. They closely resembled each other in morphology, exhibiting traits intermediate between the parental species. They were confirmed to be amphidiploids by mitotic and meiotic analyses, being 2n= 46 (MaMaCC), with pollen fertility of about 50%, which was enough to develop the subsequent progenies. Anatomical analysis of the for leaf tissue showed that the bundle sheath cells of the somatic hybrids contained some centripetally arranged organelles, like those of M. arvensis. The hybridity was also confirmed by random amplified polymorphic DNA analysis. Both chloroplast DNA and mitochondrial DNA of the somatic hybrids were estimated to be derived from M. arvensis. In leaf anatomy, the somatic hybrid showed the C3‐C4 intermediate trait as in M. arvensis. Many progenies resulted from backcrossing with parental species. The somatic hybrids are expected to be used as bridging plant material to introduce the C3‐C4 intermediate trait into Brassica crop species.
Genetic gains for yield after two back‐crosses of the interspecific hybrid Libusta (Coffea canephora P. × C. liberica Bull. Ex Hiern) to C. canephora P.
Authors: Yapo A. , Louarn J. , Montagnon C. , Weber W. E. 
Published: June 2003

AbstractThe Libusta (Coffea canephora P. × C. liberica B.) programme initiated in the seventies in Côte d'Ivoire aims at improving the quality of coffee grown in low altitudes, with a yield comparable to current commercial C. canephora clones. The second generation of back‐crosses to the C. canephora (CAN) parent, BC2, are now likely to be commercially exploited as far as yield is concerned. The best BC2 progeny yielded 1386 kg of green coffee/ha/y, averaged over five harvest years. On average, the genetic gain for yield from BC1 to BC2 reached 22%. In a factorial mating design, no interaction was observed between BC1 and CAN parents, while both main effects were highly significant. This explained that observed genetic gains and further genetic gains may be achieved with appropriate strategies.
Genetic stability and maintenance of Raphanus sativus lines with an added Brassica rapa chromosome
Authors: Kaneko Y. , Yano H. , Bang S. W. , Matsuzawa Y. 
Published: June 2003

AbstractThe genetic stability and maintenance of Raphanus sativus‐Brassica rapa monosomic chromosome addition lines (a‐h‐types MALs, 2n = 19, BC2), developed by backcrossing the synthesized amphidiploid Raphanobrassica (Raphanus sativus × Brassica rapa, 2n = 38, RRAA) with R. sativus cv. ‘Shogoin’ (2n = 18, RR), was investigated. Transmission of the added alien chromosome through selected smaller seeds (SSS) and the inheritance of morphological traits and random amplified polymorphic DNA (RAPD)‐specific markers together with meiotic chromosome configuration and seed fertility were also investigated for three successive generations (BC3 to BC5). The distinctive traits and the RAPD‐specific markers of the eight types of MAL were substantially inherited and stably maintained throughout three generations, although a few variant plants (2n =18) resembling MALs (2n = 19) and hyperploidal plants (2n = 26 and 2n = 37) were generated in the earlier generations of BC3 and BC4 in comparison with BC5. The average transmission rates for three generations ranged from 26% for both the b‐type and the d‐type to 44% for the e‐type through SSS. On the other hand, the transmission rates through randomly selected seeds (RSS) were lower, ranging from 6.5% for the f‐type to 23.5% for the b‐type. In meiosis, more than 90% of PMCs showed the 9II +1I pairing configuration at metaphase I throughout three generations. For seed fertility, when backcrossed with the radish cv. ‘Shogoin’, the values were approximately 180% to 500% with the mode around 300% with the seed harvested from a pod increasing with the advancing generations. Genetic recombination between the radish chromosomes and the added chromosome is probably rare, suggesting that the added chromosome is mostly maintained unaltered in the background of the radish genome.
Low relative humidity increases haploid production in durum wheat X maize crosses
Authors: Ballesteros J. , García‐Llamas C. , Ramírez M. C. , Martín A. , Weber W. E. 
Published: June 2003

AbstractHaploidization is a useful tool for genetic analysis and plant breeding, but a consistent and satisfactory protocol for haploid production has been difficult to achieve in durum wheat. The objective of this study was to analyze the influence of the relative humidity of the environment, when culturing detached tillers during the production of haploids plants in durum wheat by the maize method. Thirty‐eight F3 lines from eight crosses of durum wheat were pollinated with bulked pollen from three commercial maize hybrids. A mixture of 2‐4D and dicamba was used as a hormone treatment. The numbers of caryopses, embryos and haploids plants were scored. When 65‐85% (light‐dark) humidity was substituted for 55‐65% the number of haploids per spike increased notably. This increased frequency was largely attributed to a rise in the production of generated caryopses. On average, 15.2 vs. 9.3 caryopses, 5.0 vs. 2.8 embryos, and 3.1 vs. 0.6 haploid plants, per spike, were produced under low and high humidity regimes, respectively.
Associative mossy fibre LTP induced by pairing presynaptic stimulation with postsynaptic hyperpolarization of CA3 neurons in rat hippocampal slice
Authors: Sokolov Maxim V. , Rossokhin Alexej V. , M. Kasyanov Alexander , Gasparini Sonia , Berretta Nicola , Cherubini Enrico , Voronin Leon L. 
Published: May 2003

AbstractWhole cell recordings of excitatory postsynaptic potentials/currents (EPSPs/EPSCs) evoked by minimal stimulation of commissural–associative (CF) and mossy fibre (MF) inputs were performed in CA3 pyramidal neurons. Paired responses (at 50 ms intervals) were recorded before, during and after hyperpolarization of the postsynaptic membrane (20–30 mV for 15–35 min). Membrane hyperpolarization produced a supralinear increase of EPSPs/EPSCs amplitude in MF‐inputs. Synaptic responses remained potentiated for the rest of the recording period (up to 40 min) after resetting the membrane potential to control level (221 ± 60%, n = 15 and 219 ± 61%, n = 11 for MF‐EPSP and MF‐EPSC, respectively). We shall refer to this effect as hyperpolarization‐induced LTP (HI‐LTP). In the absence of afferent stimulation, membrane hyperpolarization was unable to produce HI‐LTP. In contrast to MF‐EPSPs, the mean amplitude of CF‐EPSPs did not increase significantly after hyperpolarization relative to controls (138 ± 29%, n = 22). HI‐LTP was associated with modifications of classical indices of presynaptic release: paired‐pulse facilitation, failures rate, coefficient of variation of EPSP amplitudes and quantal content. The induction of HI‐LTP was NMDA independent but was dependent on metabotropic glutamate receptors (mGluRs) activation and calcium release from inositol 1,4,5‐triphosphate (IP3)‐sensitive intracellular stores: it was prevented by mGluR antagonist, intracellular heparin and BAPTA. We conclude that while the induction of HI‐LTP was postsynaptic, its expression was presynaptic.
Medial prefrontal cortex suppression of the hypothalamic–pituitary–adrenal axis response to a physical stressor, systemic delivery of interleukin‐1β
Authors: Crane J. W. , Ebner K. , Day T. A. 
Published: May 2003

AbstractPrevious studies have shown that the medial prefrontal cortex can suppress the hypothalamic–pituitary–adrenal axis response to stress. However, this effect appears to vary with the type of stressor. Furthermore, the absence of direct projections between the medial prefrontal cortex and corticotropin‐releasing factor cells at the apex of the hypothalamic–pituitary–adrenal axis suggest that other brain regions must act as a relay when this inhibitory mechanism is activated. In the present study, we first established that electrolytic lesions involving the prelimbic and infralimbic medial prefrontal cortex increased plasma adrenocorticotropic hormone levels seen in response to a physical stressor, the systemic delivery of interleukin‐1β. However, medial prefrontal cortex lesions did not alter plasma adrenocorticotropic hormone levels seen in response to a psychological stressor, noise. To identify brain regions that might mediate the effect of medial prefrontal cortex lesions on hypothalamic–pituitary–adrenal axis responses to systemic interleukin‐1β, we next mapped the effects of similar lesions on interleukin‐1β‐induced Fos expression in regions previously shown to regulate the hypothalamic–pituitary–adrenal axis response to this stressor. It was found that medial prefrontal cortex lesions reduced the number of Fos‐positive cells in the ventral aspect of the bed nucleus of the stria terminalis. However, the final experiment, which involved combining retrograde tracing with Fos immunolabelling, revealed that bed nucleus of the stria terminalis‐projecting medial prefrontal cortex neurons were largely separate from medial prefrontal cortex neurons recruited by systemic interleukin‐1β, an outcome that is difficult to reconcile with a simple medial prefrontal cortex–bed nucleus of the stria terminalis–corticotropin‐releasing factor cell control circuit.
Agonistic encounters in aged male mouse potentiate the expression of endogenous brain NGF and BDNF: possible implication for brain progenitor cells' activation
Authors: Fiore Marco , Amendola Tiziana , Triaca Viviana , Tirassa Paola , Alleva Enrico , Aloe Luigi 
Published: May 2003

AbstractThe condition of dominance or submission following agonistic encounters in the adult male mouse is known to differentially affect brain nerve growth factor, a neurotrophin playing a role in brain remodeling, in the fine tuning of behaviour and in the regulation of the basal forebrain cholinergic neurons. During development and adult life nerve growth factor regulates brain expression of neurotransmitters and the stimulation of progenitor cells (stem cells) which, under different external stimuli, may differentiate into neuronal and/or glial cells promoting the recovery of the injured brain. However, little information is available for the aged brain. Thus in the present study we investigated the effect of the social status (‘dominance’ vs. ‘submission’) in the aged mouse on the presence of nerve growth factor, brain‐derived neurotrophic factor, choline acetyltransferase, neuropeptide Y and progenitor cells of selected brain regions. We found that aged dominant mice showed increased brain‐derived neurotrophic factor in the subventricular zone and hippocampus and increased choline acetyltransferase in the septum and basal nuclei, which were associated with increased presence of progenitor cells in the subventricular zone. Conversely, in aged subordinate mice the data showed a marked brain increase in nerve growth factor in the subventricular zone and hippocampus, choline acetyltransferase in the septum and basal nuclei and neuropeptide Y in the hippocampus and parietal cortex. The possible functional implications of these findings are discussed.
Attenuation of neuropathic pain by the nociceptin/orphanin FQ antagonist JTC‐801 is mediated by inhibition of nitric oxide production
Authors: Mabuchi Tamaki , Matsumura Shinji , Okuda‐Ashitaka Emiko , Kitano Takahiro , Kojima Hirotatsu , Nagano Tetsuo , Minami Toshiaki , Ito Seiji 
Published: May 2003

AbstractAt the spinal level, the involvement of nociceptin/orphanin FQ (N/OFQ) in pain transmission is controversial. JTC‐801, a selective nonpeptidergic N/OFQ antagonist, is a good tool to examine the involvement of endogenous N/OFQ in pathophysiological conditions. In the present study, we studied the effect of JTC‐801 on neuropathic pain induced by L5 spinal nerve transection in mice. Thermal hyperalgesia was evident on day 3 postsurgery and maintained during the 10‐day experimental period. Oral administration of JTC‐801 relieved the thermal hyperalgesia in neuropathic mice in a dose‐dependent manner. Following L5 nerve transection, the increase in nitric oxide synthase (NOS) activity was observed in the superficial layer of dorsal horn and around the central canal in the spinal cord by NADPH diaphorase histochemistry. Using the novel fluorescent nitric oxide (NO) detection dye diaminofluorescein‐FM, we confirmed that NO production increased in the spinal slice prepared from neuropathic mice and that the increase was more prominent in the ipsilateral side to the nerve transection than in the contralateral side. These increases in NOS activity and NO production in neuropathic mice were blocked by pretreatment of oral JTC‐801. Although intraperitoneal injection of the nonselective NOS inhibitor NG.‐nitro‐L‐arginine methyl ester transiently, but significantly, attenuated neuropathic hyperalgesia, inducible NOS‐deficient mice showed neuropathic pain after L5 spinal nerve transection. These results suggest that N/OFQ is involved in the maintenance of neuropathic pain and that the analgesic effect of JTC‐801 on neuropathic pain is mediated by inhibition of NO production by neuronal NOS.
Systemic or intra‐amygdala injections of glucose facilitate memory consolidation for extinction of drug‐induced conditioned reward
Authors: Schroeder Jason P. , Packard Mark G. 
Published: May 2003

AbstractThe conditioned place preference (CPP) task has been used extensively to investigate the neurobiological bases of drug‐induced reward. The initial expression of a CPP involves memory for an association between environmental stimuli and the affective state produced by a rewarding treatment. The present experiments examined the hypothesis that post‐trial administration of glucose can facilitate memory consolidation processes underlying the extinction of drug‐induced CPP behaviour. Adult male Long‐Evans rats acquired an amphetamine CPP, and subsequently received extinction training. Immediately following extinction training, separate groups of rats received peripheral (100 mg/kg, 500 mg/kg, or 2 g/kg) or intra‐amygdala (basolateral nucleus; 1.5 µg/0.5 µL or 10 µg/0.5 µL) injections of glucose or vehicle. Peripheral (100 mg/kg and 2 g/kg) and intra‐amygdala (1.5 and 10 µg) glucose injections facilitated the extinction of amphetamine CPP behaviour relative to vehicle‐injected controls. Postextinction trial peripheral or intra amygdala glucose injections that were delayed 2 h had no effect. The findings indicate that: (i) extinction of approach behaviour to drug‐associated cues involves the formation of new memories that undergo a time‐dependent consolidation process; and (ii), systemic or intra‐amygdala administration of a known memory‐enhancing agent facilitates extinction of drug‐induced CPP behaviour.
p53 Inactivation leads to impaired motor synchronization in mice
Authors: Campana Aline L. M. , Rondi‐Reig Laure , Tobin Christine , Lohof Ann M. , Picquet Florence , Falempin Maurice , Weitzman Jonathan B. , Mariani Jean 
Published: May 2003

AbstractWe have combined genetic and pharmacological approaches to investigate the behavioural consequences of inactivation of the murine p53 protein. Our behavioural analysis revealed that p53‐null mice (p53KO) exhibit a very specific and significant motor deficit in rapid walking synchronization. This deficit, observed using the rotarod test, was the only behavioural defect of p53KO mice. We demonstrated that it was not due to an increase in neuronal number or abnormal connectivity in the olivo‐cerebellar system, thought to control motor synchronization. In order to test the role of p53 in the central nervous system, we injected a pharmacological inhibitor of p53 activation, pifithrin‐α, into the cerebellum of wild‐type mice. This treatment mimicked the walking synchronization deficit of p53KO mice, suggesting that presence of p53 protein in the cerebellum is necessary to execute this synchronization of walking. Our investigation reveals a functional role of cerebellar p53 protein in adult walking synchronization.
Individual differences in prefrontal cortical activation on the Tower of London planning task: implication for effortful processing
Authors: Cazalis F. , Valabrègue R. , Pélégrini‐Issac M. , Asloun S. , Robbins T. W. , Granon S. 
Published: May 2003

AbstractSolving challenging (‘effortful’) problems is known to involve the dorsal and dorsolateral prefrontal cortex in normal volunteers, although there is considerable individual variation. In this functional magnetic resonance imaging study, we show that healthy subjects with different levels of performance in the Tower of London planning task exhibit different patterns of brain activation. All subjects exhibited significant bilateral activation in the dorsolateral prefrontal cortex, the anterior and posterior cingulate areas and the parietal cortex. However, ‘standard performers’ (performance < 70% correct) and ‘superior performers’ (performance >70% correct) differed in the patterns of activation exhibited. Superior performers showed a significantly more spatially extended activation in the left dorsolateral prefrontal cortex than did standard performers, whereas the latter group tended to show increased activation of the anterior cingulate region.
HCN channels are expressed differentially in retinal bipolar cells and concentrated at synaptic terminals
Authors: Müller Frank , Scholten Alexander , Ivanova Elena , Haverkamp Silke , Kremmer Elisabeth , Kaupp U. Benjamin 
Published: May 2003

AbstractHyperpolarization‐activated and cyclic nucleotide‐gated (HCN) channels codetermine the integrative behaviour of neurons and shape their response to synaptic stimulation. We used immunohistochemistry and patch‐clamp recording to study the composition and distribution of HCN channels in the rat retina. All four HCN channel isoforms (HCN1–4) are expressed differentially in the retina. In particular, different classes of bipolar cells have a different inventory of HCN channels. We found no evidence for the formation of heterooligomeric HCN channels. HCN channels are densely clustered at synaptic terminals of bipolar cells and photoreceptors. This suggests that HCN channels are involved in the control of transmitter release.
Temporal upregulation of prodynorphin mRNA in the primate striatum after cocaine self‐administration
Authors: Fagergren P. , Smith H. R. , Daunais J. B. , Nader M. A. , Porrino L. J. , Hurd Y. L. 
Published: May 2003

AbstractSeveral human and rat studies suggest that the striatal dynorphin system is important for neuroadaptation following cocaine exposure. In the current study, prodynorphin (PDYN) mRNA expression was examined in monkeys at initial and chronic phases of cocaine self‐administration. Adult Rhesus monkeys were trained to self‐administer food (banana flavoured pellets) or cocaine (0.03 or 0.3 mg/kg per injection) on a fixed interval 3‐min schedule for 5 or 100 sessions. Each session ended after 30 reinforcers were delivered. The PDYN mRNA expression was analysed in the precommissural striatum using in situ hybridization histochemistry. We found a specific activation of PDYN mRNA expression in the limbic‐innervated patch/striosome compartment of the dorsal caudate and dorsal putamen during the initial (i.e. 5 day) phase of the high dose cocaine self‐administration. After 100 days of the high dose exposure, the patch/striosome compartment remained activated, but an increase in PDYN mRNA levels was also evident in the sensorimotor‐connected matrix compartment of the caudate. Neither self‐administration phase resulted in significant changes in the corresponding striatal regions of the low dose cocaine‐exposed primates. Moreover, cocaine self‐administration failed to alter the PDYN mRNA expression in high‐ or low‐expressing PDYN cell populations in the nucleus accumbens during any condition studied. These results demonstrate the vulnerability of the dorsal striatum (in particular the caudate) to neuroadaptations following long‐term high dose cocaine self‐administration. In addition, the temporal nature of the changes in PDYN gene expression within the striatal compartments could reflect a change in drug responsivity that occurs during the transition to drug dependence.
Role of the medial septum diagonal band of Broca cholinergic neurons in oestrogen‐induced spine synapse formation on hippocampal CA1 pyramidal cells of female rats
Authors: Lâm Thiên‐Trí , Leranth Csaba 
Published: May 2003

AbstractOestrogen is known to influence pyramidal cell spine synapse plasticity in the CA1 subfield of the hippocampus. Apart from direct oestrogen action on the hippocampus, oestrogen effects mediated by subcortical structures are known to be important. The purpose of this study was to investigate whether the medial septum diagonal band of Broca (MSDB) takes part in mediating oestrogen effects to the hippocampus. Special attention was given to the role of cholinergic MSDB neurons that project to the hippocampus, as a rather large population of them contains oestrogen receptors and, consequently, may be sensitive to oestrogen signals. Adult female rats were ovariectomized. Oestradiol‐ and cholesterol‐filled cannulae (control) were implanted into the MSDB. To selectively eliminate the cholinergic population of MSDB neurons of oestrogen‐treated animals, a group of rats was injected with 192 IgG‐saporin (SAP) into the lateral ventricle 1 week before the cannula implant. Immunostaining with anti‐choline acetyltransferase and parvalbumin (PA) showed that cholinergic but not PA‐containing GABAergic neurons were substantially reduced in the MSDB of SAP rats. Comparative electron microscopic unbiased stereological analysis on the spine synapse density of CA1 area pyramidal cells was performed between all animal groups. Rats that received oestradiol‐filled cannulae showed a higher (30%) spine synapse density than control animals. Oestrogen‐treated rats that had received SAP treatment showed no significant difference to controls. Thus, this observation indicates that septo‐hippocampal cholinergic neurons are involved in mediating oestrogen effects to the hippocampus. The relevance of this observation to mnemonic functions and Alzheimer's disease is discussed.