Effects of bilateral lesions of the dorsolateral funiculi and dorsal columns at the level of the low thoracic spinal cord on the control of locomotion in the adult cat. I. Treadmill walking

1996 ◽  
Vol 76 (2) ◽  
pp. 849-866 ◽  
Author(s):  
W. Jiang ◽  
T. Drew
Keyword(s):  
Spinal Cord ◽  
The Other ◽  
Emg Activity ◽  
Step Cycle ◽  
Testing Period ◽  
Left Limb ◽  
Before And After ◽  
Dorsal Columns ◽  
The Right ◽  
Bilateral Lesions

1. A quantitative and longitudinal analysis of locomotion was made after bilateral lesions of the dorsolateral funiculi (DLF) and/or the dorsal columns (DC) in the lower thoracic cord (T12 or T13) in five adult cats. All cats were chronically implanted several weeks before the spinal cord lesion to permit the recording of electromyographic (EMG) activity from selected flexor and extensor muscles of the fore- and hindlimbs of each side. This allowed each cat to act as its own control when comparing the pattern and amplitude of EMG activity before and after the lesion. All experiments were also videotaped to allow an analysis of the kinematic changes before and after the lesions. Kinematic data were only analyzed for the side of the cat facing the camera; for all cats this was the left side. 2. After recovery periods of 2-5 mo, wheat-germ-agglutinated horseradish peroxidase (WGA-HRP) was injected caudal to the lesion site (normally at L2). The extent of the lesion was verified both histologically and by evaluating the number of HRP-labeled neurons in different supraspinal structures. These analyses showed that the cortico- and rubrospinal tracts (CST and RST, respectively) were completely interrupted, bilaterally, in two of five of the cats; in one of these cats the DCs were also interrupted. In the other three cats there was more variable damage, and the CST and RST were only completely interrupted on the right side of one of these animals. The DCs were completely sectioned in two of these cats. 3. During the 1st wk subsequent to the lesion, most cats had difficulty in supporting their weight and in walking. However, within 10 days all were able to walk, unaided, for extended periods on the treadmill at speeds of at least 0.35 m/s. In the two cats with the complete, bilateral DLF lesions, the animals dragged both their left and right hindpaws along the treadmill belt during the swing phase of the step cycle (paw drag) throughout the testing period of 3-5 mo. In the other three cats, paw drag in either hindlimb was only seen in the 1st 2-3 wk after the lesions, with the exception of the cat with the complete lesion of the DLF on the right side, which showed sustained paw drag in the right hindlimb throughout the testing period. 4. Significant increases in step cycle and swing duration following the lesion were observed only in the two cats with the largest lesions. In all five cats, statistical comparisons of the slopes from a linear regression analysis showed that the relationship between swing and step cycle duration was unchanged by the lesions. 5. Joint angles in the left hindlimb of the two cats with the largest lesions were generally smaller (more flexed) than in the prelesion controls. This was particularly true for the knee and ankle joints. The other three cats showed changed joint angle values for the hip, knee, and ankle only in the 1st 2-3 wk after the lesions. All of the cats, except the one with the least damage to the left DLF, exhibited increased joint excursions at the metatarsophalangeal (MTP) joint of the left limb throughout the recovery period. 6. There were sustained changes in the coupling between the hip and the knee of the left limb, together with smaller changes in the coupling of the knee and ankle in the two cats with the complete lesions of the DLF. In contrast to the prelesion controls, flexion at the ankle occurred before swing onset in these same two cats. The changes in the coordination between the hip and the knee were associated with changes in the temporal coupling between the hip flexor, sartorius (Srt), and the knee flexor, semitendinosus (St). Despite some improvement, the coupling between these two muscles never fully recovered to the prelesion values. Similar, but smaller, changes in the delay between Srt and St were also seen in two of the other three cats. (ABSTRACT TRUNCATED)

Ascending pathways in the spinal cord involved in the activation of subnucleus reticularis dorsalis neurons in the medulla of the rat

1990 ◽  
Vol 63 (3) ◽  
pp. 424-438 ◽  
Author(s):  
Z. Bing ◽  
L. Villanueva ◽  
D. Le Bars
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
The Body ◽  
Cervical Cord ◽  
Lateral Part ◽  
Neuronal Responses ◽  
C Fiber ◽  
Dorsal Columns ◽  
Dorsolateral Funiculus ◽  
The Right

1. Recordings were made from neurons in the left medullary subnucleus reticularis dorsalis (SRD) of anesthetized rats. Two populations of neurons were recorded: neurons with total nociceptive convergence (TNC), which gave responses to A delta- and C-fiber activation from the entire body after percutaneous electrical stimulation, and neurons with partial nociceptive convergence (PNC), which responded to identical stimuli with an A delta-peak regardless of which part of the body was stimulated and with a C-fiber peak of activation from some, mainly contralateral, parts of the body. 2. The effects of various, acute, transverse sections of the cervical (C4-C5) spinal cord on the A delta- and C-fiber-evoked responses were investigated by building poststimulus histograms (PSHs) after 50 trials of supramaximal percutaneous electrical stimulation of the extremity of either hindpaw (2-ms duration; 3 times threshold for C-fiber responses), before and 30-40 min after making the spinal lesion. 3. In the case of TNC neurons, hemisections of the left cervical cord blocked the responses elicited from the right hindpaw and slightly, but not significantly, diminished those evoked from the left hindpaw. Conversely, hemisections of the right cervical cord abolished TNC responses elicited from the left hindpaw without significantly affecting the responses elicited from the right hindpaw. 4. Lesioning the dorsal columns or the left dorsolateral funiculus was found not to affect the TNC neuronal responses elicited from either hindpaw. By contrast, lesioning the left lateral funiculus or the most lateral part of the ventrolateral funiculus, respectively, reduced and blocked the responses elicited from the right hindpaw without affecting those evoked from the left hindpaw. 5. After lesions that included the most lateral parts of the left ventral funiculus, PNC neuronal responses elicited from the right hindpaw were also abolished, whereas those elicited from the left hindpaw remained unchanged. 6. We conclude that the signals responsible for the activation of SRD neurons travel principally in the lateral parts of the ventrolateral quadrant, a region that classically has been implicated in the transmission of noxious information. Both a crossed and a double-crossed pathway are involved in this process. The postsynaptic fibers of the dorsal columns and the spinocervical and spinomesencephalic tracts do not appear to convey signals that activate SRD neurons. 7. The findings also suggest that lamina I nociceptive specific neurons, the axons of which travel within the dorsolateral funiculus, do not contribute very much to the activation of SRD neurons.

scholarly journals Altered modulation of sensorimotor rhythms with chronic paralysis

2017 ◽  
Vol 118 (4) ◽  
pp. 2412-2420 ◽  
Author(s):  
Stephen T. Foldes ◽  
Douglas J. Weber ◽  
Jennifer L. Collinger
Keyword(s):  
Spinal Cord ◽  
Motor Imagery ◽  
Muscle Activity ◽  
Cervical Spinal Cord ◽  
The Other ◽  
Emg Activity ◽  
Cortical Oscillations ◽  
Cord Injury ◽  
Intact Muscle ◽  
Sensorimotor Rhythms

After paralysis, the disconnection between the cortex and its peripheral targets leads to neuroplasticity throughout the nervous system. However, it is unclear how chronic paralysis specifically impacts cortical oscillations associated with attempted movement of impaired limbs. We hypothesized that μ- (8–13 Hz) and β- (15–30 Hz) event-related desynchronization (ERD) would be less modulated for individuals with hand paralysis due to cervical spinal cord injury (SCI). To test this, we compared the modulation of ERD from magnetoencephalography (MEG) during attempted and imagined grasping performed by participants with cervical SCI ( n = 12) and able-bodied controls ( n = 13). Seven participants with tetraplegia were able to generate some electromyography (EMG) activity during attempted grasping, whereas the other five were not. The peak and area of ERD were significantly decreased for individuals without volitional muscle activity when they attempted to grasp compared with able-bodied subjects and participants with SCI,with some residual EMG activity. However, no significant differences were found between subject groups during mentally simulated tasks (i.e., motor imagery) where no muscle activity or somatosensory consequences were expected. These findings suggest that individuals who are unable to produce muscle activity are capable of generating ERD when attempting to move, but the characteristics of this ERD are altered. However, for people who maintain volitional muscle activity after SCI, there are no significant differences in ERD characteristics compared with able-bodied controls. These results provide evidence that ERD is dependent on the level of intact muscle activity after SCI. NEW & NOTEWORTHY Source space MEG was used to investigate sensorimotor cortical oscillations in individuals with SCI. This study provides evidence that individuals with cervical SCI exhibit decreased ERD when they attempt to grasp if they are incapable of generating muscle activity. However, there were no significant differences in ERD between paralyzed and able-bodied participants during motor imagery. These results have important implications for the design and evaluation of new therapies, such as motor imagery and neurofeedback interventions.

Involvement of the fastigial nuclei in vagally mediated respiratory responses

1997 ◽  
Vol 82 (6) ◽  
pp. 1853-1861 ◽  
Author(s):  
Fadi Xu ◽  
Donald T. Frazier
Keyword(s):  
External Jugular Vein ◽  
Vagal Afferents ◽  
Mechanical Stimuli ◽  
Lung Inflation ◽  
Arterial Blood ◽  
Before And After ◽  
The Right ◽  
Bilateral Lesions ◽  
Respiratory Reflexes ◽  
Respiratory Responses

Xu, Fadi, and Donald T. Frazier. Involvement of the fastigial nuclei in vagally mediated respiratory responses. J. Appl. Physiol. 82(6): 1853–1861, 1997.—Previous studies have demonstrated that the cerebellum, especially the fastigial nucleus (FN), is capable of modulating respiratory responses to chemical and mechanical stimuli. Because there is evidence to show projections from vagal afferents to the FN, the goal of this study was to determine the role of the FN in the respiratory reflexes elicited by activation of vagal afferents. Experiments were performed in anesthetized (chloralose), paralyzed, and artificially ventilated cats with an occipital exposure of the cerebellum. Administration of capsaicin (Cap; 5–10 μg/kg) via the right external jugular vein at the end of inspiration and application of lung inflation (LI; 10 cmH2O) during inspiration were carried out to stimulate nonmyelinated and myelinated vagal afferents, respectively. The phrenic neurogram was recorded as an index of the respiratory motor output. Control cardiorespiratory variables [expiratory duration (Te), arterial blood pressure] and their immediate responses to stimuli were compared before and after bilateral lesions of the FN. The results showed the following. 1) Cap injection and LI resulted in a dramatic increase in Te (apnea). 2) FN lesions did not significantly alter the control Te; however, the apneic duration induced by Cap injection was prolonged. 3) Neither FN lesions nor cerebellectomy affected the apneic duration that resulted from application of LI. 4) Cold blockade of the vagi (6–8°C) eliminated the respiratory responses elicited by LI but not Cap injection; vagotomy abolished the responses to both stimuli. 5) FN lesions did not change the control ABP or its responses to either LI or Cap injection. It is concluded that the FN is involved in vagally mediated respiratory reflexes elicited by activation of nonmyelinated (C-fiber) vagal afferents.

Alternate Leg Movement Amplifies Locomotor-Like Muscle Activity in Spinal Cord Injured Persons

2005 ◽  
Vol 93 (2) ◽  
pp. 777-785 ◽  
Author(s):  
Noritaka Kawashima ◽  
Daichi Nozaki ◽  
Masaki O. Abe ◽  
Masami Akai ◽  
Kimitaka Nakazawa
Keyword(s):  
Spinal Cord ◽  
Muscle Activity ◽  
Lower Limbs ◽  
Emg Activity ◽  
Joint Movement ◽  
Experimental Conditions ◽  
Biceps Femoris Muscle ◽  
Cord Injury ◽  
Leg Movement ◽  
The Right

It is now well recognized that muscle activity can be induced even in the paralyzed lower limb muscles of persons with spinal cord injury (SCI) by imposing locomotion-like movements on both of their legs. Although the significant role of the afferent input related to hip joint movement and body load has been emphasized considerably in previous studies, the contribution of the “alternate” leg movement pattern has not been fully investigated. This study was designed to investigate to what extent the alternate leg movement influenced this “locomotor-like” muscle activity. The knee-locked leg swing movement was imposed on 10 complete SCI subjects using a gait training apparatus. The following three different experimental conditions were adopted: 1) bilateral alternate leg movement, 2) unilateral leg movement, and 3) bilateral synchronous (in-phase) leg movement. In all experimental conditions, the passive leg movement induced EMG activity in the soleus and medial head of the gastrocnemius muscles in all SCI subjects and in the biceps femoris muscle in 8 of 10 SCI subjects. On the other hand, the EMG activity was not observed in the tibialis anterior and rectus femoris muscles. The EMG level of these activated muscles, as quantified by integrating the rectified EMG activity recorded from the right leg, was significantly larger for bilateral alternate leg movement than for unilateral and bilateral synchronous movements, although the right hip and ankle joint movements were identical in all experimental conditions. In addition, the difference in the pattern of the load applied to the leg among conditions was unable to explain the enhancement of EMG activity in the bilateral alternate leg movement condition. These results suggest that the sensory information generated by alternate leg movements plays a substantial role in amplifying the induced locomotor-like muscle activity in the lower limbs.

Spinal Cord Maps of Spatiotemporal Alpha-Motoneuron Activation in Humans Walking at Different Speeds

2006 ◽  
Vol 95 (2) ◽  
pp. 602-618 ◽  
Author(s):  
Y. P. Ivanenko ◽  
R. E. Poppele ◽  
F. Lacquaniti
Keyword(s):  
Spinal Cord ◽  
Center Of Mass ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Step Cycle ◽  
Human Spinal Cord ◽  
Spinal Segments ◽  
Motoneuron Activity ◽  
Pattern Generators ◽  
Walking Speeds

Functional MRI (fMRI) imaging of motoneuron activity in the human spinal cord is still in its infancy, and it will remain difficult to apply to walking. Here we present a viable alternative for documenting the spatiotemporal maps of α-motorneuron (MN) activity in the human spinal cord during walking, similar to the method recently reported for the cat. We recorded EMG activity from 16 to 32 ipsilateral limb and trunk muscles in 13 healthy subjects walking on a treadmill at different speeds (1–7 km/h) and mapped the recorded patterns onto the spinal cord in approximate rostrocaudal locations of the motoneuron pools. This approach can provide information about pattern generator output during locomotion in terms of segmental control rather than in terms of individual muscle control. A striking feature we found is that nearly every spinal segment undergoes at least two cycles of activation in the step cycle, thus supporting the idea of half-center oscillators controlling MN activation at any segmental level. The resulting spatiotemporal map patterns seem highly stereotyped over the range of walking speeds studied, although there were also some systematic redistributions of MN activity with speed. Bursts of MN activity were either temporally aligned across several spinal segments or switched between different segments. For example, the center of mass of MN activity in the lumbosacral levels generally shifted from rostral to caudal positions in two cycles for each step, revealing four major activation foci: two in the upper lumbar segments and two in the sacral segments. The results are consistent with the presence of at least two and possibly more pattern generators controlling the activation of lumbosacral MNs.

Capsaicin-induced activation of pulmonary vagal C fibers produces reflex laryngeal closure in the rat

2006 ◽  
Vol 101 (4) ◽  
pp. 1104-1112 ◽  
Author(s):  
I-Jung Lu ◽  
Kun-Ze Lee ◽  
Ji-Chuu Hwang
Keyword(s):  
Intravenous Administration ◽  
Digital Camera ◽  
Vocal Folds ◽  
Emg Activity ◽  
Glottal Closure ◽  
C Fibers ◽  
Before And After ◽  
Subglottal Pressure ◽  
Male Wistar Rats ◽  
The Right

Our recent studies show that intravenous administration of capsaicin induces enhancement of the intralaryngeal thyroarytenoid (TA) branch but a reduction of the intralaryngeal abducent branch, suggesting that the glottis is likely closed by capsaicin. The aim of the present study was to examine whether the glottis is adducted by intravenous administration of capsaicin. Electromyographic (EMG) activity of the TA muscle, subglottal pressure (SGP), and glottal behavior were evaluated before and after intravenous administration of capsaicin in male Wistar rats that were anesthetized and tracheostomized. Catheters were placed in the femoral artery and vein, as well as in the right jugular vein. Low and high doses of capsaicin (0.625 and 1.25 μg/kg) produced apnea and increases in the amplitude of the TA EMG. This enhancement of the TA EMG was observed during apnea as well as during recovery from apnea. Moreover, the onset of the TA EMG was advanced such that it commenced earlier during inspiration. Concomitantly, the SGP substantially increased. Increases in both the TA EMG and SGP were abolished after bilateral sectioning of the recurrent laryngeal nerve. In some animals, movement of the vocal folds was recorded by taking a motion picture with a digital camera under a surgical microscope. With intravenous administration of capsaicin, a tight glottal closure, decreases in blood pressure, and bradycardia were observed. These results strongly suggest that glottal closure is reflexively induced by intravenous administration of capsaicin and that closure of the glottis is beneficial for the defense of the airway and lungs when an animal is exposed to environmental irritants.

scholarly journals Clinical Effects of Theophylline on Inspiratory Muscle Drive in Tetraplegia

1999 ◽  
Vol 13 (3) ◽  
pp. 191-197 ◽  
Author(s):  
Gary T. Ferguson ◽  
Narendra Khanchandani ◽  
Chris D. Lattin ◽  
Harry G. Goshgarian
Keyword(s):  
Spinal Cord ◽  
Muscle Function ◽  
Muscle Force ◽  
Cervical Spinal Cord ◽  
Inspiratory Muscle ◽  
Emg Activity ◽  
Neural Activation ◽  
Clinical Effects ◽  
Respiratory Drive ◽  
Before And After

Theophylline has been shown to restore diaphragmatic function in animals following cervical spinal cord hemisection, which induces hemidiaphragm paralysis. Although theophylline had been used clinically in the treatment of various pulmonary diseases, its effects on respiratory muscle function in cervical spinal cord injured tetraplegics has not been studied. In the present case study, we evaluated a patient injured in 1979 with a chronic asymmetric C5-7 tetraplegia (left C5-6, right C6-7) before and after receiving theophylline chronically by mouth for three weeks and again before and after receiving acute intravenous (IV) aminophylline after the effects of the chronic drug administration wore off. Neural activation to inspiratory muscles was assessed by right and left parasternal intercostal and diaphragm EMGs during quiet breathing and max imal inspiratory efforts. Global respiratory drive was assessed by P100, and inspiratory muscle force was assessed by maximal inspiratory pressures and vital capacity. Both long-term orally administered and acute IV theophylline increased neural activation to the diaphragm, especially on the more affected left side. Theophylline treatment was also associated with an increase in global central respiratory drive and inspiratory muscle force, without changing expiratory airflows. Left diaphragm EMG activity was markedly increased following the administration of theophylline. Of interest, upper parasternal intercostal EMG activity was also recruited on the left in spite of being below the level of cervical injury. We speculate that the administration of theophylline in selected patients with an asymmetric cervical spinal cord injury may activate la tent bulbospinal respiratory pathways and improve inspiratory muscle function, re ducing the likelihood of associated respiratory failure.

scholarly journals Locomotor impact of beneficial or nonbeneficial H-reflex conditioning after spinal cord injury

2014 ◽  
Vol 111 (6) ◽  
pp. 1249-1258 ◽  
Author(s):  
Yi Chen ◽  
Lu Chen ◽  
Rongliang Liu ◽  
Yu Wang ◽  
Xiang Yang Chen ◽  
...  
Keyword(s):  
Spinal Cord ◽  
H Reflex ◽  
Spinal Reflex ◽  
Step Cycle ◽  
Reflex Pathway ◽  
Cord Injury ◽  
Kinematic Analyses ◽  
Spinal Cord Contusion ◽  
The Right ◽  
The Impact

When new motor learning changes neurons and synapses in the spinal cord, it may affect previously learned behaviors that depend on the same spinal neurons and synapses. To explore these effects, we used operant conditioning to strengthen or weaken the right soleus H-reflex pathway in rats in which a right spinal cord contusion had impaired locomotion. When up-conditioning increased the H-reflex, locomotion improved. Steps became longer, and step-cycle asymmetry (i.e., limping) disappeared. In contrast, when down-conditioning decreased the H-reflex, locomotion did not worsen. Steps did not become shorter, and asymmetry did not increase. Electromyographic and kinematic analyses explained how H-reflex increase improved locomotion and why H-reflex decrease did not further impair it. Although the impact of up-conditioning or down-conditioning on the H-reflex pathway was still present during locomotion, only up-conditioning affected the soleus locomotor burst. Additionally, compensatory plasticity apparently prevented the weaker H-reflex pathway caused by down-conditioning from weakening the locomotor burst and further impairing locomotion. The results support the hypothesis that the state of the spinal cord is a “negotiated equilibrium” that serves all the behaviors that depend on it. When new learning changes the spinal cord, old behaviors undergo concurrent relearning that preserves or improves their key features. Thus, if an old behavior has been impaired by trauma or disease, spinal reflex conditioning, by changing a specific pathway and triggering a new negotiation, may enable recovery beyond that achieved simply by practicing the old behavior. Spinal reflex conditioning protocols might complement other neurorehabilitation methods and enhance recovery.

scholarly journals The results of open surgical treatment of bilateral staghorn and multiple nephrolithiasis

2018 ◽  
Vol 99 (4) ◽  
pp. 722-729
Author(s):  
S B Imamverdiev ◽  
T A Talibov ◽  
I F Makhmudov
Keyword(s):  
Surgical Treatment ◽  
Renal Artery ◽  
Open Surgery ◽  
Left Kidney ◽  
The Other ◽  
Before And After ◽  
The Status ◽  
Group 2 ◽  
Open Surgical Treatment ◽  
The Right

Aim. To determine the status and to increase the effectiveness of open surgical treatment of bilateral staghorn nephrolithiasis. Methods. We studied the results of surgical treatment of 250 patients who underwent open surgery for severe forms of bilateral staghorn nephrolithiasis. The patients were divided into four groups according to the features of changes in both kidneys and ureters - group 1 included 125 (50.0%) patients with bilateral staghorn nephrolithiasis, group 2 - 35 (14.0%) patients with staghorn nephrolithiasis of solitary or the only functioning kidney, 70 (28.0%) patients with unilateral staghorn nephrolithiasis and solitary or multiple kidney or ureter stones on the other side were included into group 3, and group 4 inlcuded 20 (8.0%) patients with unilateral staghorn nephrolithiasis and nonobstructive hydronephrosis and other diseases on the other side. The age of patients ranged from 7 to 76 years old, ranging among children from 7 to 18 years (average age 12.1±0.4 years) and among adults from 19 to 76 years (average age 46.4±0.6 years). Among patients, 121 (48.4%) were males and 129 (51.6%) were females. Results. Surgical tactics and the results of performed surgeries in certain groups were studied. Overall, 127 (50.8±3.8%) of 250 patients underwent surgery on the right kidney, and 123 (49.2±3.2%) - on the left kidney. To achieve minimal blood loss during the surgery, in 20% of cases renal artery was clamped. To protect kidneys from ischemia, 3 mg/kg of furosemide, 0.2 mg/kg of verapamil and 1 mg/kg of methylethylpiridinol were used before and after clamping of the renal artery. Open surgical treatment of 250 patients with bilateral staghorn nephrolithiasis was successful in 246 (98.4±0.8%) patients. In case of residual stones, extracorporeal or ureterorenoscopic shock wave lithotripsy was performed. Conclusion. Despite the wide application of modern endoscopic methods of therapy in the treatment of this group of patients, in complex forms of staghorn nephrolithiasis open surgery is more effective.

scholarly journals Lateralized Brainstem and Cervical Spinal Cord Responses to Aversive Sounds: A Spinal fMRI Study

2018 ◽  
Vol 8 (9) ◽  
pp. 165 ◽  
Author(s):  
Stephen Smith ◽  
Tiffany Kolesar ◽  
Jennifer Kornelsen
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Brain Structures ◽  
The Other ◽  
Auditory Stimuli ◽  
Fmri Study ◽  
Spinal Fmri ◽  
Auditory Cortices ◽  
The Right ◽  
Influence Activity

Previous research has delineated the networks of brain structures involved in the perception of emotional auditory stimuli. These include the amygdala, insula, and auditory cortices, as well as frontal-lobe, basal ganglia, and cerebellar structures involved in the planning and execution of motoric behaviors. The aim of the current research was to examine whether emotional sounds also influence activity in the brainstem and cervical spinal cord. Seventeen undergraduate participants completed a spinal functional magnetic resonance imaging (fMRI) study consisting of two fMRI runs. One run consisted of three one-minute blocks of aversive sounds taken from the International Affective Digitized Sounds (IADS) stimulus set; these blocks were interleaved by 40-s rest periods. The other block consisted of emotionally neutral stimuli also drawn from the IADS. The results indicated a stark pattern of lateralization. Aversive sounds elicited greater activity than neutral sounds in the right midbrain and brainstem, and in right dorsal and ventral regions of the cervical spinal cord. Neutral stimuli, on the other hand, elicited less neural activity than aversive sounds overall; these responses were left lateralized and were found in the medial midbrain and the dorsal sensory regions of the cervical spinal cord. Together, these results demonstrate that aversive auditory stimuli elicit increased sensorimotor responses in brainstem and cervical spinal cord structures.

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