23 research outputs found
Multisensory information facilitates reaction speed by enlarging activity difference between superior colliculus hemispheres in rats
Animals can make faster behavioral responses to multisensory stimuli than to unisensory stimuli. The superior colliculus (SC), which receives multiple inputs from different sensory modalities, is considered to be involved in the initiation of motor responses. However, the mechanism by which multisensory information facilitates motor responses is not yet understood. Here, we demonstrate that multisensory information modulates competition among SC neurons to elicit faster responses. We conducted multiunit recordings from the SC of rats performing a two-alternative spatial discrimination task using auditory and/or visual stimuli. We found that a large population of SC neurons showed direction-selective activity before the onset of movement in response to the stimuli irrespective of stimulation modality. Trial-by-trial correlation analysis showed that the premovement activity of many SC neurons increased with faster reaction speed for the contraversive movement, whereas the premovement activity of another population of neurons decreased with faster reaction speed for the ipsiversive movement. When visual and auditory stimuli were presented simultaneously, the premovement activity of a population of neurons for the contraversive movement was enhanced, whereas the premovement activity of another population of neurons for the ipsiversive movement was depressed. Unilateral inactivation of SC using muscimol prolonged reaction times of contraversive movements, but it shortened those of ipsiversive movements. These findings suggest that the difference in activity between the SC hemispheres regulates the reaction speed of motor responses, and multisensory information enlarges the activity difference resulting in faster responses
Chiral separation of N-(trans-4-isopropylcyclohexylcarbonyl)-D,L-phenylalanine isomers by high performance liquid chromatography
Biochemical studies on the use of sodium hyaluronate in the anterior eye segment. II. The molecular behavior of sodium hyaluronate injected into anterior chamber of rabbits
Measurement of portal blood flow by an ultrasonic โduplexโ system composed of a pulsed Doppler flowmeter and a linear-type real time B mode electroscanner
2012ๅนดใใ2016ๅนดใซใใใฆใใคใธใงใชใขๅๆฑ้จใงๆคๅบใใใใฉใใตใฆใคใซในใฎ้บไผๅญฆ็่งฃๆ
Lassa virus (LASV) is endemic in parts of West Africa where it causes Lassa fever (LF), a viral hemorrhagic fever with frequent fatal outcomes. The diverse LASV strains are grouped into six major lineages based on the geographical location of the isolated strains. In this study, we have focused on the lineage II strains from southern Nigeria. We determined the viral sequences from positive cases of LF reported at tertiary hospitals in Ebonyi and Enugu between 2012 and 2016. Reverse transcription-polymerase chain reaction (RT-PCR) showed that 29 out of 123 suspected cases were positive for the virus among which 11 viral gene sequences were determined. Phylogenetic analysis of the complete coding sequences of the four viral proteins revealed that lineage II strains are broadly divided into two genetic clades that diverged from a common ancestor 195 years ago. One clade, consisting of strains from Ebonyi and Enugu, was more conserved than the other from Irrua, although the four viral proteins were evolving at similar rates in both clades. These results suggested that the viruses of these clades have been distinctively evolving in geographically separate parts of southern Nigeria. Furthermore, the epidemiological data of the 2014 outbreak highlighted the role of human-to-human transmission in this outbreak, which was supported by phylogenetic analysis showing that 13 of the 16 sequences clustered together. These results provide new insights into the evolution of LASV in southern Nigeria and have important implications for vaccine development, diagnostic assay design, and LF outbreak management.้ทๅดๅคงๅญฆๅญฆไฝ่ซๆ ๅญฆไฝ่จ็ชๅท:ๅ(ๅปๆญฏ่ฌ)็ฒ็ฌฌ1107ๅท ๅญฆไฝๆไธๅนดๆๆฅ:ๅนณๆ30ๅนด12ๆ5ๆฅAuthor: Olamide K. Oloniniyi, Uche S. Unigwe, Sayaka Okada, Mayuko Kimura, Shota Koyano, Yukiko Miyazaki, Michael O. Iroezindu, Nnenna A. Ajayi, Chinedu M. Chukwubike, Nneka M. Chika-Igwenyi, Anne C. Ndu, Damian U. Nwidi, Haruka Abe, Shuzo Urata, Yohei Kurosaki, Jiro YasudaCitation: PLoS Neglected Tropical Diseases, 12(11), e0006971; 2018Nagasaki University (้ทๅดๅคงๅญฆ)่ชฒ็จๅ