A neural correlate of visceral emotional responses: evidence from fMRI of the thoracic spinal cord. Soc Cogn Affect Neurosci

Functional magnetic resonance imaging (fMRI) of thoracic spinal cord neurons was used to examine the neural correlates of visceral emotional responses. Participants completed four spinal fMRI runs involving passive viewing (i.e. no movement) and motoric responses to negative or neutral images. Negative images, particularly in the movement condition, elicited robust activity in motoric nuclei, indicating action preparedness. These images also enhanced activity in autonomic and sensory nuclei, thus providing a clear neural representation of visceral responses to emotional stimuli. Keywords: magnetic resonance imaging; functional MRI; spinal cord; thoracic spinal cord; emotion A core feature of emotional experience is a subjective visceral response to a stimulus or event. These responses imbue events with a vividness that enhances perception Quantifying neural activity related to such phenomenologically complex experiences poses significant methodological challenges. Paramount among these is the difficulty in separating neural activity related to the bodily responses from activity associated with the cognitive interpretation of these responses. Previous research has successfully identified key structures related to the latter. Activation of the right insula has been consistently linked with interoception One such region is the spinal cord, which has different sensory, motoric and autonomic functions but is not directly related to any cognitive process. The spinal cord is divided into four different regionscervical, thoracic, lumbar and sacraleach of which is composed of a number of individual segments projecting to and receiving information from different regions of the body. Each of these segments consists of dorsal and ventral aspects, which correspond to sensory and motoric activity and, in the thoracic segments, a lateral aspect that corresponds to autonomic activity. Although often thought to be a simple structure, the patterns of activity in the spinal cord reflect a number of potentially interacting systems. Numerous separate descending pathways from the brain modulate motoric regions of the spinal cord, and similarly, multiple separate ascending pathways bring different types of somatosensory information back to the brain. In addition to these brain-spinal cord interactions, the spinal cord houses interneurons that project both intra-segmentally and intersegmentally and that are involved in a number of reflexive responses that occur independent of the brain. Therefore, studies examining the excitability of a single descending pathway from the brain (e.g. the corticospinal tract) are measuring only a fraction of the activity occurring in the spinal cord. Examining activity at the level of the spinal cord itself will provide researchers with unique information about nervous system activity that cannot be identified using traditional brain fMRI (functional magnetic resonance imaging). In previous studies, we have used fMRI of the spinal cord ('spinal fMRI'; Stroman, 2005) to examine whether the spinal cord activity can be modulated by emotional stimuli. In the first study to examine spinal cord responses to emotions, we measured activity in the cervical spinal cord, which innervates the upper limbs including the hands (Smith and Kornelsen, 2011). We found that negative emotional stimuli elicited greater levels of activity in ventral (motoric) regions of several spinal cord segments, particularly those related to hand responses. This activity was more pronounced when participants made a movement (pressed a button on a response pad) than when they passively viewed the emotional images. Because of this very specific pattern of activity, we suggested that spinal cord neurons show evidence of emotion-dependent 'action preparedness'. However, emotional responses are obviously not limited to rapid gestural responses, as shown by measurements of the cervical spinal cord. Instead, emotional responses generally involve muscle tension in the chest and abdomen as well as autonomic nervous system activity. Neuroanatomical studies suggest that these responses should be linked with activity in a different region of the spinal cord, the thoracic cord. Spinal nerves emanating from the thoracic spinal cord innervate muscles in the trunk and abdomen, stimulating muscle contraction of these regions. Afferent somatosensory projections from the peripheral nervous system synapse with this region as well. These responses are likely linked to the subjective awareness of our emotionally aroused state. Additionally, the thoracic spinal cord is critical for a number of autonomic nervous system responses ranging from pupil dilation and cardiopulmonary responses (segments T1-T4) to the secretion of norepinephrine and epinephrine by the adrenal medulla (T10-T12; see Shields, 1993, for a detailed review). Therefore, measuring activit

Functional MRI of the thoracic spinal cord during vibration sensation

Purpose: To demonstrate that it is possible to acquire accurate functional magnetic resonance images from thoracic spinal cord neurons. Materials and Methods: The lower thoracic spinal dermatomes (T7\u2013T11) on the right side of the body were mechanically stimulated by vibration for 15 participants. Neuronal responses to vibration sensation were measured in the thoracic spinal cord using a HASTE sequence on a 3 Tesla MRI system. Results: Signal increases were observed in the corresponding lower thoracic spinal cord segments ipsilateral to the side of stimulation in the dorsal aspect of the spinal cord. Conclusion: This is the \ufb01rst study to provide proof of principle that functional imaging of the entire thoracic spinal cord is possible, by detecting neuronal activity in the thoracic spinal cord during sensory stimulation using spinal fMRI.Peer reviewed: YesNRC publication: Ye

Peer Victimization Is Associated With Neural Response to Social Exclusion

Peer victimization is associated with increased risk for mental health problems. These adverse psychological outcomes are linked with altered cognitive and emotional processes and their related neural functioning. In the present study, by using functional magnetic resonance imaging (fMRI), we examined whether peer victimization was associated with heightened neural response to social exclusion. Participants (N = 45; Mage = 17.7 years, SD = 0.60; 36 women) included three mutually exclusive groups: peer-victimized individuals (targets of bullying), cyberdefenders (defended peers who were being cyberbullied), and controls (not involved as targets or cyberdefenders). All participants underwent an fMRI scan while playing Cyberball, an experimental paradigm that simulates social exclusion. Peer victimization was associated with increased neural response in the left amygdala, left parahippocampal gyrus, left inferior frontal operculum, and right fusiform gyrus. Understanding the acute neural response to social exclusion in peer-victimized individuals may provide insight into their increased risk for poor mental health

Search for high-energy neutrinos from gravitational wave event GW151226 and candidate LVT151012 with ANTARES and IceCube

The Advanced LIGO observatories detected gravitational waves from two binary black hole mergers during their first observation run (O1). We present a high-energy neutrino follow-up search for the second gravitational wave event, GW151226, as well as for gravitational wave candidate LVT151012. We find two and four neutrino candidates detected by IceCube, and one and zero detected by Antares, within �500s around the respective gravitational wave signals, consistent with the expected background rate. None of these neutrino candidates are found to be directionally coincident with GW151226 or LVT151012. We use nondetection to constrain isotropic-equivalent high-energy neutrino emission from GW151226, adopting the GW event�s 3D localization, to less than 2�10^51�2�10^54??ergby Anand Sengupta et al

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

International audienceSpinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO

International audienceDuring their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes of IMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100  M⊙, with spins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained to be less than 0.93  Gpc−3 yr−1 in comoving units at the 90% confidence level, an improvement of nearly 2 orders of magnitude over previous upper limits

First low-frequency Einstein@Home all-sky search for continuous gravitational waves in Advanced LIGO data

International audienceWe report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the first Advanced LIGO observing run. This search investigates the low frequency range of Advanced LIGO data, between 20 and 100 Hz, much of which was not explored in initial LIGO. The search was made possible by the computing power provided by the volunteers of the Einstein@Home project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population, corresponding to a sensitivity depth of 48.7  [1/Hz]. At the frequency of best strain sensitivity, near 100 Hz, we set 90% confidence upper limits of 1.8×10-25. At the low end of our frequency range, 20 Hz, we achieve upper limits of 3.9×10-24. At 55 Hz we can exclude sources with ellipticities greater than 10-5 within 100 pc of Earth with fiducial value of the principal moment of inertia of 1038  kg m2