Emotion-dependent responses in spinal cord neurons: A spinal fMRI study

Abstract

Previous research has demonstrated that emotional stimuli receive preferential processing in the brain. In the current study, functional magnetic resonance imaging was utilized to determine if emotion-specific responses are detectable in the cervical spinal cord. During the passive (i.e., non-motoric) perception of images, activity was detected in the left dorsal and right ventral spinal cord in response to negative emotional stimuli; however, this pattern was reversed in response to neutral and positive stimuli. Critically, during active motoric responses to images, there was greater activity in the ventral cervical spinal cord in response to negative emotional stimuli than to neutral stimuli. These results demonstrate preferential motor responses to negative emotional images by the spinal cord, likely indicating an enhancement of activity in response to threat. Research highlights Activity in the cervical spinal cord is influenced by emotional images.  Positive and negative images elicit opposite patterns of activity during perception.  Threatening images increase activity in the cervical spinal cord during movements.  Activity occurs in the ventral aspect of the cord during the negative condition.  Activity is lateralized to the side producing movement in the negative condition.

Neural Responses to Consciously and Unconsciously Perceived Emotional Faces: A Spinal fMRI Study

“…Indeed, consciously perceived fearful faces elicited much less activity than either consciously perceived angry or neutral faces. This result was surprising given that earlier spinal fMRI found pronounced activity in ventral/motoric neurons in segments C2–C5 when participants passively viewed emotionally negative images [16]. A key difference between the results is the stimuli used.…”

“…A key difference between the results is the stimuli used. Whereas the current result involved the presentation of emotional faces, Smith and Kornelsen [16] used pictorial stimuli from the IAPS image database [19]; it is possible that the movement implied by the complex emotional scenes led to the motoric responses to these stimuli (see [20] for a demonstration of this issue in a brain fMRI study).…”

“…Cervical spinal cord fMRI data was analyzed with the use of a custom-written Matlab script [37] used in previous studies [15,16,18]. First, images underwent a slice timing correction and were coaligned to correct for bulk motion using a nonlinear 3D adjustment to align each volume to the 3rd volume of the set.…”

“…Recent research has demonstrated that this emo-motoric system extends to both the cervical [15,16] and thoracic spinal cord [17,18]. Using fear- and disgust-eliciting images, Smith and Kornelsen [16] demonstrated that the perception of negative stimuli leads to an increase in neuronal activity in ventral regions of spinal cord segments C5–C8.…”

“…Using fear- and disgust-eliciting images, Smith and Kornelsen [16] demonstrated that the perception of negative stimuli leads to an increase in neuronal activity in ventral regions of spinal cord segments C5–C8. This emotion-dependent activity is similar to the enhanced responses in extrastriate and motoric regions of the brain and likely reflects the nervous system preparing motoric responses to the perceived stimuli.…”