Inhibition of Connexin43 hemichannels impairs spatial short-term memory without affecting spatial working memory

Astrocytes are active players in higher brain function as they can release gliotransmitters, which are essential for synaptic plasticity. Various mechanisms have been proposed for gliotransmission, including vesicular mechanisms as well as non-vesicular ones, for example by passive diffusion via connexin hemichannels (HCs). We here investigated whether interfering with connexin43 (Cx43) HCs influenced hippocampal spatial memory. We made use of the peptide Gap19 that blocks HCs but not gap junction channels and is specific for Cx43. To this end, we microinfused transactivator of transcription linked Gap19 (TAT-Gap19) into the brain ventricle of male NMRI mice and assessed spatial memory in a Y maze. We found that the in vivo blockade of Cx43 HCs did not affect the locomotor activity or spatial working memory in a spontaneous alternation Y maze task. Cx43 blockade did however significantly impair the spatial short-term memory in a delayed spontaneous alternation Y maze task. These results indicate that Cx43 HCs play a role in spatial short-term memory

Astrocytic Connexin43 channels as candidate targets in epilepsy treatment

In epilepsy research, emphasis is put on exploring non-neuronal targets such as astrocytic proteins, since many patients remain pharmacoresistant to current treatments, which almost all target neuronal mechanisms. This paper reviews available data on astrocytic connexin43 (Cx43) signaling in seizures and epilepsy. Cx43 is a widely expressed transmembrane protein and the constituent of gap junctions (GJs) and hemichannels (HCs), allowing intercellular and extracellular communication, respectively. A plethora of research papers show altered Cx43 mRNA levels, protein expression, phosphorylation state, distribution and/or functional coupling in human epileptic tissue and experimental models. Human Cx43 mutations are linked to seizures as well, as 30% of patients with oculodentodigital dysplasia (ODDD), a rare genetic condition caused by mutations in the GJA1 gene coding for Cx43 protein, exhibit neurological symptoms including seizures. Cx30/Cx43 double knock-out mice show increased susceptibility to evoked epileptiform events in brain slices due to impaired GJ-mediated redistribution of K+ and glutamate and display a higher frequency of spontaneous generalized chronic seizures in an epilepsy model. Contradictory, Cx30/Cx43 GJs can traffic nutrients to high-energy demanding neurons and initiate astrocytic Ca2+ waves and hyper synchronization, thereby supporting proconvulsant effects. The general connexin channel blocker carbenoxolone and blockers from the fenamate family diminish epileptiform activity in vitro and improve seizure outcome in vivo. In addition, interventions with more selective peptide inhibitors of HCs display anticonvulsant actions. To conclude, further studies aiming to disentangle distinct roles of HCs and GJs are necessary and tools specifically targeting Cx43 HCs may facilitate the search for novel epilepsy treatments

Homological perspective on edge modes in linear Yang-Mills theory

We provide an elegant homological construction of the extended phase space for linear Yang-Mills theory on an oriented and time-oriented Lorentzian manifold M with a time-like boundary ∂M that was proposed by Donnelly and Freidel [JHEP 1609, 102 (2016)]. This explains and formalizes many of the rather ad hoc constructions for edge modes appearing in the theoretical physics literature

Homological perspective on edge modes in linear Yang–Mills and Chern–Simons theory

We provide an elegant homological construction of the extended phase space for linear Yang-Mills theory on an oriented and time-oriented Lorentzian manifold M with a time-like boundary @M that was proposed by Donnelly and Freidel [JHEP 1609, 102 (2016)]. This explains and formalizes many of the rather ad hoc constructions for edge modes appearing in the theoretical physics literature. Our construction also applies to linear Chern-Simons theory, in which case we obtain the extended phase space introduced by Geiller

"Prévention de l'épuisement du proche aidant dans des situations de soins palliatifs à domicile: comment l'infirmière accompagne le proche aidant dans l'expérience qui est la sienne, dans une situation de soins palliatifs à domicile, en vue de prévenir son épuisement ?" : revue de la littérature scientifique : travail de Bachelor

Le domaine des soins à domicile est en pleine mutation en Suisse. Les soins palliatifs à domicile sont en pleine croissance, et le nombre de personnels qu’ils nécessiteraient ne peut pas être atteint par les institutions de soins à domicile seules. C’est la raison pour laquelle les proches aidants sont de plus en plus sollicités. Cependant ces personnes sans grande expérience dans les soins palliatifs et dans une étape de transition, ne possèdent pas forcément les stratégies pour se protéger d’un épuisement quasiment certain. Ils doivent ainsi pouvoir bénéficier du soutien adapté et suffisant pour ne pas devenir à leur tour des patients. La théorie de l’Humaindevenant de R. R. Parse décrit la manière dont une personne traverse l’expérience intense que représente une prise en soins palliative à domicile, en prenant en compte l’unicité de la personne et permettant une adaptation fine du système de santé environnant. Les auteurs ont consulté les bases de données scientifiques de références et ont extrait des articles rapportant des exemples de bonnes pratiques. Ils ont analysé ces écrits à la lumière de la théorie de l’Humaindevenant, donnant ainsi des pistes de réflexions utilisables dans la pratique infirmière quotidienne