Stable transmission of targeted gene modification using single-stranded oligonucleotides with flanking LNAs

Targeted mutagenesis directed by oligonucleotides (ONs) is a promising method for manipulating the genome in higher eukaryotes. In this study, we have compared gene editing by different ONs on two new target sequences, the eBFP and the rd1 mutant photoreceptor βPDE cDNAs, which were integrated as single copy transgenes at the same genomic site in 293T cells. Interestingly, antisense ONs were superior to sense ONs for one target only, showing that target sequence can by itself impart strand-bias in gene editing. The most efficient ONs were short 25 nt ONs with flanking locked nucleic acids (LNAs), a chemistry that had only been tested for targeted nucleotide mutagenesis in yeast, and 25 nt ONs with phosphorothioate linkages. We showed that LNA-modified ONs mediate dose-dependent target modification and analyzed the importance of LNA position and content. Importantly, when using ONs with flanking LNAs, targeted gene modification was stably transmitted during cell division, which allowed reliable cloning of modified cells, a feature essential for further applications in functional genomics and gene therapy. Finally, we showed that ONs with flanking LNAs aimed at correcting the rd1 stop mutation could promote survival of photoreceptors in retinas of rd1 mutant mice, suggesting that they are also active in vivo

Etude des processus émotionnels et cognitifs impliqués dans le biais de récupération des souvenirs autobiographiques chez les consommateurs de substances

La prévalence du rappel de souvenirs généraux ou biais de surgénéralité a été originellement envisagée comme une stratégie d'évitement émotionnel. Cependant, d'autres mécanismes peuvent être impliqués dans ce phénomène, comme un déficit du contrôle exécutif et un effet de capture lié à des modèles schématiques de soi indifférenciés et à la rumination mentale. Dans cette thèse, le rappel des souvenirs autobiographiques chez les consommateurs de substances a été investigué à travers trois études expérimentales, dans lesquelles des mécanismes impliqués dans le biais de récupération des souvenirs spécifiques ont été étudiés. L'ensemble des études mettent en évidence une difficulté d'accès aux souvenirs spécifiques chez les consommateurs de substances. A travers une première étude, nous avons démontré dans cette population que cette perturbation était observable aussi bien chez les patients dépendants que chez les individus présentant un abus de substances et qu'elle ne pouvait être réduite à un déficit global de la mémoire épisodique. La deuxième étude a permis de mettre en évidence l'existence d'un lien entre le niveau de spécificité des souvenirs autobiographiques et l'utilisation des stratégies cognitives d'évitement chez des patients dépendants et en population générale. Ce constat appuie l'hypothèse d'une stratégie de régulation émotionnelle en jeu dans la perturbation du rappel autobiographique. En revanche, aucon résultat ne permet de montrer l'implication d'un déficit du contrôle exécutif dans la réduction de la spécificité des souvenirs autobiographiques. Enfin, une troisième étude a permis de démontrer que le niveau de différenciation émotionnelle prédit le niveau de récupération des souvenirs autobiographiques chez les individus dépendants et en population générale. Une réduction de la spécificité persiste après arrêt de la concommation chez les patients dépendants. Ces trois études confirment une difficulté d'accès aux souvenirs spécifiques chez les consommateurs de substances, et permettent de mieux identifier les mécanismes impliqués dans ce déficit. Un ensemble de perspectives de recherches et d'applications cliniques sera discutéA general mode of autobiographical memory retrieval also called overgeneral memory was originally assumed as a strategy of emotional avoidance. Nevertheless, other mechanisms can be involved in this phenomenon, such as a deficit on inhibition processes or a capture effect linked to undifferentiated self-schematic models or to rumination. In this thesis, autobiographical memories retrieval was investigated in three experimental studies, through which we tried to determine what were the mechanisms underlying the deficit of autobiographical retrieval in those patients. The results of the three studies reveal a difficulty in accessing specific memories in substance dependent patients. In the first study, we showed that this deficit was observable in dependent patients as well as in substance abusers and that it cannot be reduced to a global deficit of episodic memory. The existence of a link between the level of autobiographical memories specificity and the use of cognitive avoidance strategies in dependent patients and in general population was depicted in the second study. This result gives further evidence for the affect-regulating quality of reduced memory specificity. Then, through the third study, we proved thet the level of emotional diffrenciation predicts the level of memory specificity in dependent patients and in general population. A reduced specificity is still observable after withdrawal in dependent patients. These three studies confirm the existence of a difficulty in specific memories retrieving in substances consumers, and help at better identifying the mechanisms involved in this deficit. Some research perspectives and clinical applications will be discussedLILLE3-BU (590092101) / SudocSudocFranceF

Stratégies de surgénéralisation des souvenirs autobiographiques chez les consommateurs de cannabis et les polyconsommateurs de substances psychoactives

National audienceObjectives.—Psychoactive substance consumption induces cognitive impairments in terms ofepisodic memory and attentional and executive function deficits. This study aims to investigatewhether the recall of autobiographical memories is disturbed in substance consumers, and inparticular whether those patients tend to evoke memories at a general level rather than ata specific level when confronted by an emotional cue word. Furthermore, we aim to verifywhether adopting a more general memory retrieving style is a dynamic phenomenon and if itdepends on the type of substance consumed.Design and methods.—The participants of this research were 51 cannabis users, including17 occasional cannabis users, 17 cannabis abusers and 17 individuals addicted to cannabis. Theywere compared to 18 multiple substance-dependent individuals and to 38 nondependent individuals.Participants were subjected to the Williams and Scott (1988) [39] autobiographicalmemory test. After an assessment of the mode of substance consumption, several clinicaldimensions were measured, such as depression (BDI), anxiety (STAI Y A and B), alexithymia(TAS 20) and episodic memory (RLS-15).Results.—The results show that the percentage of general positive and negative memoriesrecalled increases progressively as the consumption takes on the characteristics of addictivebehavior, while we observe no deficit in episodic memory. The level of alexithymia evolved inparallel with the percentage of general memories. These results are not dependent on the typeof substance used and can not be explained by the level of depression.Conclusions.—Overgeneralization is a phenomenon observable in psychoactive substanceconsumers, whatever the type of substances used, which sets in progressively as the dependencedevelops. Our results show that overgeneralization is not only due to an impairment ofmnesic abilities, implying that this phenomenon could be underlined by several mechanisms.The role of overgeneralization as a functional avoidance established in attempt to protect individualsfrom emotion resurgence is discussed. Furthermore, the impact of deficits in executivefunctions on the recall of autobiographical memoriesDes perturbations cognitives sont observées chez les consommateurs de substancespsychoactives, en particulier au niveau des processus attentionnels et des fonctions exécutivesmais aussi de la mémoire. Le but de cette recherche est d’étudier chez ces patientsl’organisation de leurs souvenirs autobiographiques. On cherche à vérifier s’ils utilisent un modede récupération général de leurs souvenirs autobiographiques, et si ce phénomène s’amplifie enfonction de l’importance de la consommation. Cinquante et un consommateurs de cannabis ontparticipé à cette étude, dont un groupe de consommateurs occasionnels, un groupe d’individusprésentant des conduites d’abus et un groupe d’individus dépendants. Ils ont été comparés à ungroupe de 18 sujets dépendants polyconsommateurs et un groupe de 38 participants témoins.L’ensemble des participants a répondu au test de mémoire autobiographique de Williams etScott (1988) [39], après une évaluation clinique concernant leur consommation, leur niveaude dépression, d’anxiété, d’alexithymie et la mémoire épisodique. Les résultats montrent uneaugmentation du nombre de souvenirs autobiographiques à la fois pour les souvenirs positifset négatifs. Cette surgénéralisation s’amplifie à mesure que la consommation s’approche d’uncomportement de dépendance, alors qu’aucun déficit majeur de la mémoire épisodique n’estobservé. Les patients dépendants au cannabis surgénéralisent autant leurs souvenirs que lespolyconsommateurs.© L’Encéphale, Paris

Dérèglements émotionnels chez les consommateurs de substances psychoactives : une revue de la littérature

National audienceSince the first assumptions suggesting emotional deficits in psychoactive substance consumers, some other concepts referring to emotional awareness, emotion regulation or theory of mind complete the first approach studying alexithymia. The first investigation methods used were self-report questionnaire and those actually are associated to direct and experimental measures. Given the heterogeneity of emotional concepts studied and of emotion assessment methods, this paper aims at reviewing existing empirical studies showing the existence of a deficit in emotional information processing in substance consumers. These studies depict a difficulty in comprehending, recognizing and discriminating their own emotional states and those of others, and a deficit of emotional experience.Depuis les premières hypothèses suggérant des troubles émotionnels chez les consommateurs de substances psychoactives, aujourd’hui d’autres concepts relatifs à la conscience émotionnelle, à la régulation émotionnelle ou la théorie de l’esprit viennent compléter les premières approches étudiant l’alexithymie. Les méthodes d’investigation, à l’origine principalement basées sur des autoquestionnaires, sont actuellement associées à des mesures directes et expérimentales. Au regard de l’hétérogénéité des concepts émotionnels et des méthodes d’évaluation, cette revue de la littérature propose de recenser l’ensemble des études empiriques, objectivant l’existence de troubles du traitement de l’information émotionnelle chez les consommateurs de substances. Ces études montrent une difficulté dans l’appréhension, la reconnaissance et la discrimination de leurs états émotionnels et de ceux d’autrui, ainsi qu’un déficit du vécu émotionnel

Flashbulb memories of the Charlie Hebdo attack

Flashbulb memories refer to the vivid recall of the circumstances of first learning about significant public events. Our paper assesses whether these memories were triggered by the attack on the..

Characterization of Self-Defining Memories in Individuals with Severe Alcohol Use Disorders After Mid-Term Abstinence: The Impact of the Emotional Valence of Memories

BACKGROUND: Self-defining memories (SDM) are distinguished from other autobiographical memory (AM) processes to delineate those associated with the sense of personal identity and continuity in one's individual history. With chronic alcohol consumption, the construction of such memories may be modified in terms of specificity, valence, meaning-making, and evoked topics. This study sought to characterize SDM in a population of 27 patients with alcohol use disorder (AUD) who had been abstinent for at least 2 months compared with 28 control participants. METHODS: Besides cognitive and clinical assessment, participants were told to describe verbally and date 5 SDM and their narratives were recorded. For each memory, 5 dimensions were evaluated: level of specificity, emotional valence, integration of meaning, topics, and distance of memory in time. RESULTS: Overall, SDM of participants with AUD were specifically characterized by (i) low specificity, (ii) low integration, (iii) a predominance of memories with negative emotional valence and a low frequency of positive memories, and (iv) a low frequency of topics related to success. When different dimensions of the SDM were crossed, their characteristics depended mainly on the valence of the memory. Negative memories were more frequent, more specific and more integrated, while positive SDM were less frequent, less specific and less integrated. CONCLUSIONS: The results underline the construction of a form of SDM with drinking problems that is mainly characterized by the disruption of positive memory and the presence of highly specific and integrated negative experiences. A disruption of the integration process modulated by the valence of memories could have repercussions on maintaining a sense of personal identity, the pursuit of personal goals and on social adaptability, and could constitute one of the main risks associated with persistent drinking problems. These results highlight the relevance of developing AM training programs for patients with AUD

Flashbulb memories of the Paris attacks

Flashbulb memories are vivid autobiographical memories of the circumstances where an individual first learns about emotionally significant public events. Our paper assesses whether these memories were triggered by the attacks of Friday 13 November 2015 in Paris. Two hundred and ninety-one participants answered a web-based questionnaire that assessed their memory of the circumstances in which they first learned of the attacks. The questionnaire also assessed vividness, rehearsal, emotion, surprise and novelty. The results showed substantial and vivid recall of the context in which the participants first learned of the event. This recall was associated with fair rehearsal, negative emotional valence, surprise, and novelty. Regression analysis showed that the flashbulb recall was predicted by negative emotion. Negative emotion seems to play a key role in the formation of flashbulb memories, at least those associated with the Paris attacks

Autobiographical memory compromise in Alzheimer's disease: a cognitive and clinical overview

Autobiographical memory refers to memory for personal information. The compromise of autobiographical memory in Alzheimer's disease (AD) results in a loss of knowledge about events and facts that defined the patients' life, and consequently, degradation of their self-knowledge and sense of identity. The compromise of autobiographical memory in AD can be attributed to a diminished subjective experience of memory and a diminished sense of the self. Our review provides a comprehensive overview of cognitive and clinical processes that may be involved in difficulties to retrieve autobiographical memories in Alzheimer's disease. Our review also proposes a theoretical model according to which, the diminished ability to retrieve contextual information and the overgenerality of recall result in a diminished subjective experience of past and future thinking. Besides its theoretical contribution, our review proposes clinical applicability for evaluation and rehabilitation of autobiographical memory in AD