What Happens in Between? Human Oscillatory Brain Activity Related to Crossmodal Spatial Cueing

Previous studies investigated the effects of crossmodal spatial attention by comparing the responses to validly versus invalidly cued target stimuli. Dynamics of cortical rhythms in the time interval between cue and target might contribute to cue effects on performance. Here, we studied the influence of spatial attention on ongoing oscillatory brain activity in the interval between cue and target onset. In a first experiment, subjects underwent periods of tactile stimulation (cue) followed by visual stimulation (target) in a spatial cueing task as well as tactile stimulation as a control. In a second experiment, cue validity was modified to be 50%, 75%, or else 25%, to separate effects of exogenous shifts of attention caused by tactile stimuli from that of endogenous shifts. Tactile stimuli produced: 1) a stronger lateralization of the sensorimotor beta-rhythm rebound (15–22 Hz) after tactile stimuli serving as cues versus not serving as cues; 2) a suppression of the occipital alpha-rhythm (7–13 Hz) appearing only in the cueing task (this suppression was stronger contralateral to the endogenously attended side and was predictive of behavioral success); 3) an increase of prefrontal gamma-activity (25–35 Hz) specifically in the cueing task. We measured cue-related modulations of cortical rhythms which may accompany crossmodal spatial attention, expectation or decision, and therefore contribute to cue validity effects. The clearly lateralized alpha suppression after tactile cues in our data indicates its dependence on endogenous rather than exogenous shifts of visuo-spatial attention following a cue independent of its modality

Molecular mechanisms and cellular functions of cGAS-STING signalling

The cGAS–STING signalling axis, comprising the synthase for the second messenger cyclic GMP–AMP (cGAS) and the cyclic GMP–AMP receptor stimulator of interferon genes (STING), detects pathogenic DNA to trigger an innate immune reaction involving a strong type I interferon response against microbial infections. Notably however, besides sensing microbial DNA, the DNA sensor cGAS can also be activated by endogenous DNA, including extranuclear chromatin resulting from genotoxic stress and DNA released from mitochondria, placing cGAS–STING as an important axis in autoimmunity, sterile inflammatory responses and cellular senescence. Initial models assumed that co-localization of cGAS and DNA in the cytosol defines the specificity of the pathway for non-self, but recent work revealed that cGAS is also present in the nucleus and at the plasma membrane, and such subcellular compartmentalization was linked to signalling specificity of cGAS. Further confounding the simple view of cGAS–STING signalling as a response mechanism to infectious agents, both cGAS and STING were shown to have additional functions, independent of interferon response. These involve non-catalytic roles of cGAS in regulating DNA repair and signalling via STING to NF-κB and MAPK as well as STING-mediated induction of autophagy and lysosome- dependent cell death. We have also learnt that cGAS dimers can multimerize and undergo liquid–liquid phase separation to form biomolecular condensates that could importantly regulate cGAS activation. Here, we review the molecular mechanisms and cellular functions underlying cGAS–STING activation and signalling, particularly highlighting the newly emerging diversity of this signalling pathway and discussing how the specificity towards normal, damage-induced and infection-associated DNA could be achieved

Die Trauma-Maschine

Trauma bleibt aufgrund der etymologischen Herkunft des Begriffs mit Verwundungen verbunden. In diesem Zusammenhang wird diskutiert, inwiefern körperliche Wunden Affekte symbolisieren, die mit Brüchen in Wahrnehmung, Sinnstiftung und letztlich auch der Identitätsfindung assoziiert sind. Die Studie geht der Frage nach, wodurch körperliche Verwundungen zum Ausdruck psychischer Ausnahmezustände erhoben werden. Diese Diskrepanz wird an psychoanalytische Diskurse und kulturwissenschaftliche Debatten herangeführt, die Trauma als Ausgangspunkt von Subjektivierung, Wahrnehmung und Identitätsbildung betrachten. Dabei werden zudem die Zusammenhänge zwischen Trauma, Unfällen und maschinellen Ausfällen beleuchtet, durch die Trauma als Anlass somatischer und psychischer Irritationen in den Fokus tritt. Im Anschluss rücken fünf ausgewählte Positionen der zeitgenössischen Kunst exemplarisch in den Fokus, um die eingehenden Diskussionen kontextuell zu vertiefen

Proprioceptive head posture-related processing in human polysensory cortical areas

Besides visual input and vestibular afferents, proprioceptive input from muscle spindle receptors of the neck region contributes to the perception of egocentric space. Using fMRI we performed a neck muscle vibration paradigm in humans in order to detect brain areas involved in processing changes of the head position in relation to the rest of the body. We identified a network of primary and secondary cortical areas: (I) regions that presumably receive direct proprioceptive thalamic input such as areas 3a, 2, S2 and the parieto-insular vestibular cortex (PIVC), (II) foci in the intraparietal sulcus, motor and premotor areas, and the frontal eye field (FEF). Activation of the former reflect early stages of proprioceptive processing, nevertheless these areas contain polysensory subdivisions such as area 3aNv, which also receives vestibular afferents. Together with area PIVC and the vestibular field in area 2 (2v), area 3aNv constitutes the inner vestibular circuit, an interconnected cortical triangle of polysensory areas that project to the posterior parietal cortex (PPC), which is known to be involved in polysensory integration. With respect to possible analogies in the monkey, we speculate that the activation we observed in the PPC is closely related to the LIP and VIP regions of the macaque