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Arribas, M.

Publications and source records attributed to Arribas, M..

2 recordsLinked to original sources

Reactivity to conditioned threat cues is distinct from exploratory drive in the elevated plus-maze.

Fear and anxiety are adaptive states that allow humans and animals alike to respond appropriately to threatening cues in their environment. Commonly used tasks for studying behaviour akin to fear and anxiety in rodent models are pavlovian threat conditioning and the elevated plus maze (EPM) respectively. In threat conditioning the rodents learn to associate an aversive event with a specific stimulus or context. The learnt association between the two stimuli (the memory) can then be recalled by re-exposing the subject to the conditioned stimulus. The elevated plus maze is argued to measure the agoraphobic avoidance of the brightly lit open maze arms in crepuscular rodents. These two tasks have been used extensively, yet research into whether they interact is scarce. We investigated whether recall of an aversive memory, across contextual, odour or auditory modalities, would potentiate anxiety-like behaviour in the elevated plus maze. The data did not support that memory recall, even over a series of timepoints, could influence EPM behaviour. Furthermore, there was no correlation between EPM behaviour and conditioned freezing in independent cohorts tested in the EPM before or after auditory threat conditioning. Further analysis found the production of 22kHz ultrasonic vocalisations revealed the strongest responders to a conditioned threat cue. These results are of particular importance for consideration when using the EPM and threat conditioning to identify individual differences, and the possibility to use the tasks in batteries of tests without cross-task interference.

neuroscience↗

Investigating facial information content in the hand area of individuals with a congenital and acquired missing hand

Cortical remapping after hand loss in the primary somatosensory cortex (S1) is thought to be predominantly dictated by cortical proximity, with adjacent body parts remapping into the deprived area. Traditionally, this remapping has been characterised by changes in the lip representation, which is assumed to be the immediate neighbour of the hand based on electrophysiological research in non-human primates. However, the orientation of facial somatotopy in humans is debated, with contrasting work reporting both an inverted and upright topography. We aimed to fill this gap in the S1 homunculus by investigating the topographic organisation of the face. Using both univariate and multivariate approaches we examined the extent of face-to-hand remapping in individuals with a congenital and acquired missing hand (hereafter one-handers and amputees, respectively), relative to two-handed controls. Participants were asked to move different facial parts (forehead, nose, lips, tongue) during fMRI scanning. We first report evidence for an upright facial organisation in all three groups, with the upper face and not the lips bordering the hand area. We further found little evidence for remapping of all tested facial parts in amputees, with no significant relationship to the chronicity of their PLP. In contrast, we found converging evidence for a complex pattern of face remapping in congenital one-handers across all facial parts, where the location of the cortical neighbour - the forehead - is shown to shift away from the deprived hand area, which is subsequently activated by the lips and the tongue. Together, our findings demonstrate that the face representation in humans is highly plastic, but that this plasticity is restricted by the developmental stage of input deprivation, rather than cortical proximity.

neuroscience↗