The anticipation, perception of affective touch in women with, recovered from Anorexia Nervosa

Disruptions in reward processing and anhedonia have long been observed in Anorexia Nervosa (AN). Interoceptive deficits have also been observed in AN, including reduced tactile pleasure. However, the extent to which this tactile anhedonia is specifically liked to an impairment in a specialized, interoceptive C-tactile system originating at the periphery, or a more top-down mechanism in the processing of tactile pleasantness remains debated. Here, we investigated differences between patients with and recovered from AN and healthy controls in the perception of pleasantness of touch delivered in a CT-optimal versus a CT-non-optimal manner, and in their top-down, anticipatory beliefs about the perceived pleasantness of touch. To this end, we measured the anticipated pleasantness of various materials touching the skin and the perceived pleasantness of light, dynamic touch applied to theforearmof 27 women with AN, 24 women who have recovered and 30 healthy controls using C Tactile (CT) afferents-optimal (slow) and non-optimal (fast) velocities. Our results showed that both clinical groups anticipated tactile experiences and rated delivered tactile stimuli as less pleasant than healthy controls, but the latter difference was not related to the CT optimality of the stimulation. Instead, differences in the perception of CT-optimal touch were predicted by differences in top-down beliefs, alexithymia and interoceptive sensibility. Thus, tactile anhedonia in AN might persist as a trait even after otherwise successful recovery of AN and it is not linked to a bottom-up interoceptive deficit in the CT system, but rather to a learned, defective top-down anticipation of tactile pleasantness

The relationship between interoception and agency and its modulation by heartbeats: an exploratory study.

Interoception, the sense of the internal physiological state of the body, theoretically underpins aspects of self-representation. Experimental studies link feelings of body ownership to interoceptive perception, yet few studies have tested for association between the sense of agency and interoceptive processing. Here, we combined an intentional binding paradigm with cardiac measures of interoceptive processing (behavioural performance on a heartbeat discrimination task, and effects of timing within the cardiac cycle) in twenty-six non-clinical participants as an exploratory study. We found performance accuracy on the heartbeat discrimination task correlated positively with the intentional binding effect, an index of sense of agency (β = 0.832, p = 0.005), even after controlling for effects of age, sex, educational level, heart rate, heart rate variability and time accuracy. The intentional binding effect was enhanced during cardiac systole (compared to diastole) in individuals with greater heartbeat discrimination accuracy (β = 0.640, p = 0.047). These findings support the proposal that interoception contributes to mechanisms underlying the emergence of sense of agency

Spin density studies on p-O2NC6F4CNSSN: A heavy p-block organic ferromagnet

A complete picture of the spin density distribution in the organic radical p-O2NC6F4CNSSN has been obtained by a combination of polarized neutron diffraction, electron paramagnetic resonance (EPR), and electron-nuclear double resonance (ENDOR) spectroscopies, and ab initio density-functional theory (DFT) calculations. Polarized neutron diffraction revealed that the spin distribution is predominantly localized on the N and S atoms (+0.25μB and +0.28μB, respectively) of the heterocyclic ring with a small negative spin density on the heterocyclic C atom (−0.06μB). These spin populations are in excellent agreement with both ab initio DFT calculations (spin populations on the C, N, and S sites of −0.07, 0.22 and 0.31, respectively) and cw-EPR studies which estimated the spin population on the N site as 0.24. The DFT calculated spin density revealed less than 1% spin delocalization onto the perfluoroaryl ring, several orders of magnitude lower than the density on the heterocyclic ring. cw-ENDOR studies at both X-band (9 GHz) and Q-band (34 GHz) frequencies probed the spin populations on the two chemically distinct F atoms. These spin populations on the F atoms ortho and meta to the dithiadiazolyl ring are of magnitude 10−3 and 10−4, respectively

Estudios conformacionales de la bencidrilamina

La bencidrilamina (BB2) y sus derivados obtenidqs por sustitución arílica y/o amínica presentan actividad inhibidora de los espasmos de la musculatura lisa. Como punto de partida de una investigación cuya finalidad es el diseño de nuevos derivados con mayor actividad y especificidad se estudió, mediante difracción de rayos X de monocristal, la geometría de la bencidrilamina en su forma de clorhidrato, encontrándose que presenta una conformación helicoidal, con los anillos aproximadamente perpendiculares entre sí. Cálculos de mecánica molecular para la molécula libre de bencidrilamina y de su forma protonada (bencidrilamonio), utilizando distintos potenciales, muestran que la conformación de energía mínima depende de la inclusión o no de las interacciones coulombianas. Puesto que el estado relevante para la función biológica es en solución acuosa, se efectuaron cálculos de energía mínima en presencia de agua y se comenzó el análisis mediante dinámica molecular. La simulación se lleva a cabo a presión y temperatura constante en una caja cúbica en presencia de 216 moléculas de agua (SPC/E). Se discute la relación entre la geometría en el estado sólido y las geometrías predichas para la molécula libre y solvatada.Facultad de Ciencias ExactasInstituto de Física de Líquidos y Sistemas Biológico

Limbic neurochemical changes in patients with functional motor symptoms

ObjectiveTo assess by magnetic resonance spectroscopy (MRS) the N-acetylaspartate, myo-inositol, choline, sum of glutamate and glutamine (Glx), and creatine (Cr) content in the anterior cingulate cortex (ACC)/medial prefrontal cortex (mPFC) and in the occipital cortex (OCC) (control region) in patients with functional motor symptoms (FMS) and healthy controls, and to determine whether neurochemical limbic changes as estimated by MRS correlate with FMS-related motor symptom severity, alexithymia, anxiety, depression, and quality of life.MethodsThis case-control study enrolled 10 patients with FMS and 10 healthy controls. Participants underwent MRS and were tested with the Mini-Mental State Examination, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, 20-Item Toronto Alexithymia Scale, and EuroQol 5D.ResultsIn patients with FMS, MRS showed increased Glx/Cr in the ACC/mPFC but normal content in the control OCC. All the other metabolites tested were normal in both regions. The increased Glx/Cr content in the ACC/mPFC correlated with alexithymia, anxiety, and severity of symptoms.ConclusionsThe abnormal limbic Glx increase could have a crucial pathophysiologic role in FMS, possibly by altering limbic-motor interactions, ultimately leading to abnormal movements

Structural-magnetic correlations on the first dinuclear spin crossover d⁴ system

The triple decker dinuclear Cr(II) salt [(5-C5Me5)Cr(µ2:5-P5)Cr(5-C5Me5)]+ (SbF6)– has been structurally characterised by multiple temperature X-ray diffraction experiments from 290 K to 12 K. This material shows changes in its structural features which correlate with its magnetic response, including a structural transition with a change of symmetry from the orthorhombic space group Fddd to the monoclinic I2/a at 160 K and an abrupt rearrangement of electron density at 23 K

The neuromodulatory effect of tDCS in patients affected by functional motor symptoms: an exploratory study

Background: Recent studies have shown how emotional and cognitive factors might combine together to determine the onset and maintenance of functional motor symptoms (FMS). Nevertheless, no studies have assessed whether brain circuits involved in regulation and processing of emotions and attention might be influenced by neuromodulation. The purpose of this study was to evaluate the effect of a single anodic tDCS session over the right posterior parietal cortex in subjects with FMS and in healthy individuals. Materials and methods: Nine patients and seven healthy subjects underwent two sessions of tDCS (real and sham), in a randomized order. At the end of each session, all participants underwent the heart beat detection task (interoceptive sensitivity) and the Posner paradigm (spatial attention). Results: After sham stimulation, patients with FMS showed significantly lower interoceptive sensitivity and greater cueing effect for reaction times at the Posner paradigm than healthy controls. There was a significant improvement between the levels of interoceptive sensitivity after real and sham stimulation in the whole group of participants and in the group of patients with FMS. Conclusions: Our study provides first indications for a neuromodulatory effect of a single anodic tDCS session over the right posterior parietal cortex on interoceptive sensitivity in subjects with FMS