Oligodendrocyte development and differentiation in the rumpshaker mutation

The jimpy rumpshaker (jprsh) mutation is an amino acid substitution in exon 4 (Ile186[RIGHTWARDS ARROW]Thr) of the proteolipid protein (PLP) gene on the X chromosome. Affected mice show moderate hypomyelination of the central nervous system (CNS) with increased numbers of oligodendrocytes in the white matter of the spinal cord, a feature distinguishing them from other PLP mutations such as jp, in which premature cell death occurs with reduced numbers of oligodendrocytes. Myelin sheaths of jprsh immunostain for myelin basic protein (MBP) and DM-20, but very few contain PLP. This study examines the differentiation of oligodendrocytes cultured from the spinal cords of young mutant and wild type mice using various surface and cytoplasmic antigenic markers to define the stage of development. The majority of oligodendrocytes from mutant mice progress normally to express MBP; approximately 30%, relative to wild type, contain DM-20 at the in vivo age of 16 days, but very few immunostain for PLP or the O10 and O11 markers. The morphology of mutant cells in respect to membrane sheets and processes appears similar to normal. The jprsh oligodendrocyte is, therefore, characterized by a failure to express the markers indicative of the most mature cell; however, it is probably able to achieve a normal period of survival. These data, taken in conjunction with previous results, suggest that the PLP gene has at least two functions; one, probably involving PLP, is concerned with a structural role in normal myelin compaction; the other, perhaps related to DM-20 (or another lower molecular weight proteolipid), is essential for cell survival. The mutation in jprsh at residue 186 suggests that this region, which is common to PLP and DM-20, is not critical for this latter function

Evening Telegram, 1915-03-10

The Evening Telegram began publication in St. John's on 3 April 1879 and remains in print today under the title The Telegram. It was published daily except Sunday through to 1958, the frequency changing thereafter. -- The total collection has been split into several parts; this portion contains from 1900-1918

Your words are my words: Effects of acting together on encoding

Item does not contain fulltextSocial influences on action and memory are well established. However, it is unknown how acting together affects the incidental encoding of information. The present study asked whether coactors encode information that is relevant to a partner's task, but irrelevant to their own task. In Experiment 1, participants performed a categorization task alone and together, followed by a surprise free recall test where they were asked to recall items from the categorization task. Recall was better not only for items that participants had responded to themselves, but also for items that their coactor had responded to, than for items that had not required a response. The same results were found in Experiment 2, even though financial incentives motivated participants to only encode words they had responded to themselves. Together, the findings suggest that performing tasks together can modulate how information relevant to coactors is processed. Shared task representations may act as a vehicle for establishing shared memories