Segmental organization of visceral and somatic input onto C3-T6 spinothalamic tract cells of the monkey

1992 ◽  
Vol 68 (5) ◽  
pp. 1575-1588 ◽  
Author(s):  
S. F. Hobbs ◽  
M. J. Chandler ◽  
D. C. Bolser ◽  
R. D. Foreman
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Urinary Bladder ◽  
Visceral Pain ◽  
Cell Activity ◽  
Afferent Input ◽  
Spinothalamic Tract ◽  
Afferent Fibers ◽  
Increased Activity ◽  
Stimulation Of

1. Referred pain of visceral origin has three major characteristics: visceral pain is referred to somatic areas that are innervated from the same spinal segments as the diseased organ; visceral pain is referred to proximal body regions and not to distal body areas; and visceral pain is felt as deep pain and not as cutaneous pain. The neurophysiological basis for these phenomena is poorly understood. The purpose of this study was to examine the organization of viscerosomatic response characteristics of spinothalamic tract (STT) neurons in the rostral spinal cord. Interactions were determined among the following: 1) segmental location, 2) effects of input by cardiopulmonary sympathetic, greater splanchnic, lumbar sympathetic, and urinary bladder afferent fibers, 3) location of excitatory somatic field, e.g., hand, forearm, proximal arm, or chest, 4) magnitude of response to hair, skin, and deep mechanoreceptor afferent input, and 5) regional specificity of thalamic projection sites. 2. A total of 89 STT neurons in segments C3-T6 were characterized for responses to visceral and somatic stimuli. Neurons were activated antidromically from the contralateral ventroposterolateral oralis or caudalis nuclei of the thalamus. Cell responses to visceral and somatic stimuli were not different on the basis of the thalamic site of antidromic activation. Recording sites for 61 neurons were located histologically; 87% of lesion sites were located in laminae IV-VII or X. There was no relationship between response properties of the neurons and spinal laminar location. 3. Different responses to visceral stimuli were observed in three zones of the rostral spinal cord: C3-C6, C7-C8, and T1-T6. In C3-C6, urinary bladder distension (UBD) and electrical stimulation of greater splanchnic and lumbar sympathetic afferent fibers inhibited STT cells. Electrical stimulation of cardiopulmonary sympathetic afferents increased cell activity in C5 and C6 and either excited or inhibited STT cells in C3 and C4. In the cervical enlargement (C7-C8), STT cells generally were either inhibited or showed little response to stimulation of visceral afferent fibers. In T1-T6, input from greater splanchnic and cardiopulmonary sympathetic afferent nerves increased activity of STT cells. Lumbar sympathetic afferent input inhibited cells in T1-T2 and had little effect on cells in T3-T6, whereas UBD decreased cell activity in all segments studied. 4. In general, stimulation of somatic structures increased activity of STT neurons in segments that received primary afferent innervation from the excitatory somatic receptive field or in the segments immediately adjacent to these segments. Only input from the forelimb, especially the hand, markedly excited cells in C7 and C8.+

Convergence of phrenic and cardiopulmonary spinal afferent information on cervical and thoracic spinothalamic tract neurons in the monkey: implications for referred pain from the diaphragm and heart

1991 ◽  
Vol 65 (5) ◽  
pp. 1042-1054 ◽  
Author(s):  
D. C. Bolser ◽  
S. F. Hobbs ◽  
M. J. Chandler ◽  
W. S. Ammons ◽  
T. J. Brennan ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Mechanical Stimulation ◽  
Afferent Input ◽  
Excitatory Effect ◽  
Spinothalamic Tract ◽  
Distal Limb ◽  
Afferent Fibers ◽  
Spinal Segments ◽  
Spinal Afferents ◽  
Stimulation Of

1. Spinothalamic tract (STT) neurons in the C3-T6 spinal segments were studied for their responses to stimulation of phrenic and cardiopulmonary spinal afferent fibers. A total of 142 STT neurons were studied in 44 anesthetized, paralyzed monkeys (Macaca fascicularis). All neurons were antidromically activated from the ventroposterolateral nucleus and/or medial thalamus. 2. Electrical stimulation of phrenic afferent fibers (PHR) excited 43/58 (74%), inhibited 2/58 (3%), and did not affect 13/58 (13%) of cervical STT neurons. Neurons with excitatory somatic fields confined to the proximal limb or encompassing the whole limb were excited to a significantly greater extent by electrical stimulation of PHR than were neurons with somatic fields confined to the distal limb. Mechanical stimulation of PHR by probing the exposed diaphragm excited 11/22 (50%), inhibited 3/22 (14%), and did not affect 8/22 (36%) cervical STT neurons. 3. The technique of minimum afferent conduction velocity (MACV) was used to obtain information about the identity of the PHR that excited 35 cervical STT neurons. Evidence was obtained for excitation of these neurons by group II and III PHR. The mean +/- SE MACV for all neurons was 14 +/- 2 m/s. 4. Electrical stimulation of cardiopulmonary spinal afferent fibers excited 41/57 (72%), inhibited 8/57 (14%), and did not affect 8/57 (14%) of cervical STT neurons. Neurons with excitatory somatic fields confined to the proximal limb or encompassing the whole limb were excited to a significantly greater extent by electrical stimulation of cardiopulmonary spinal afferents than were neurons with somatic fields confined to the distal limb. 5. Excitatory convergence of PHR and cardiopulmonary spinal afferent input was observed for 36/57 (63%) cervical STT neurons. 6. Electrical stimulation of PHR excited 36/84 (43%), inhibited 25/84 (30%), and did not affect 23/84 (27%) of thoracic STT neurons. All of these neurons received excitatory cardiopulmonary spinal afferent input. 7. Neurons were more likely to be excited by electrical stimulation of PHR if they were located in C3-C6 spinal segments. Furthermore, the net excitatory effect of PHR input decreased in more caudal segments, such that thoracic STT neurons were weakly excited relative to cervical STT neurons. 8. We conclude that cervical STT neurons with excitatory somatic fields that include or are restricted to proximal sites are excited by electrical or mechanical stimulation of PHR. Those effects demonstrate a physiological substrate for pain referred from the diaphragm to the shoulder in patients with pleural effusions or subphrenic abscesses.(ABSTRACT TRUNCATED AT 400 WORDS)

Vagal afferent inhibition of primate thoracic spinothalamic neurons

1983 ◽  
Vol 50 (4) ◽  
pp. 926-940 ◽  
Author(s):  
W. S. Ammons ◽  
R. W. Blair ◽  
R. D. Foreman
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Background Activity ◽  
Linear Regression Analysis ◽  
Cell Activity ◽  
High Threshold ◽  
Thoracic Spinal Cord ◽  
Afferent Fibers ◽  
Vagal Afferent ◽  
Stimulation Of

Spinothalamic (ST) neurons in the C8-T5 segments of the spinal cord were examined for responses to electrical stimulation of the left thoracic vagus nerve (LTV). Seventy-one ST neurons were studied in 39 anesthetized monkeys (Macaca fascicularis). Each neuron could be excited by manipulation of its somatic field and by electrical stimulation of cardiopulmonary sympathetic afferent fibers. LTV stimulation resulted in inhibition of the background activity of 43 (61%) ST neurons. Nine (13%) were excited, 3 (4%) were excited and then inhibited, while 16 (22%) did not respond. There was little difference among these groups in terms of the type of somatic or sympathetic afferent input although inhibited cells tended to be more prevalent in the more superficial laminae. The degree of inhibition resulting from LTV stimulation was related, in a linear fashion, to the magnitude of cell activity before stimulation. LTV inhibition of background activity was similar among wide dynamic range, high threshold, and high-threshold cells with inhibitory hair input. Any apparent differences in LTV inhibitory effects among these groups were accounted for by the differences in ongoing cell activity as predicted by linear regression analysis. LTV stimulation inhibited responses of 32 of 32 ST cells to somatic stimuli. In most cases the stimulus was a noxious pinch; however, LTV stimulation also inhibited responses to innocuous stimuli such as hair movement. Bilateral cervical vagotomy abolished the inhibitory effect of LTV stimulation on background activity (six cells) or responses to somatic stimuli (seven cells). Stimulation of the cardiac branch of the vagus inhibited activity of three cells to a similar degree as LTV stimulation, while stimulation of the vagus below the heart was ineffective in reducing activity of 10 cells. We conclude that LTV stimulation alters activity of ST neurons in the upper thoracic spinal cord. Vagal inhibition of ST cell activity was due to stimulation of cardiopulmonary vagal afferent fibers coursing to the brain stem, which appear to activate descending inhibitory spinal pathways. Vagal afferent activity may participate in processing of somatosensory information as well as information related to cardiac pain.

Responses of primate spinothalamic tract neurons to electrical stimulation of hindlimb peripheral nerves

1975 ◽  
Vol 38 (1) ◽  
pp. 132-145 ◽  
Author(s):  
R. D. Foreman ◽  
A. E. Applebaum ◽  
J. E. Beall ◽  
D. L. Trevino ◽  
W. D. Willis
Keyword(s):  
Electrical Stimulation ◽  
Mechanical Stimulation ◽  
Nerve Fibers ◽  
Mechanical Stimuli ◽  
Spinothalamic Tract ◽  
Antidromic Activation ◽  
Lumbosacral Spinal Cord ◽  
Afferent Fibers ◽  
To Receive ◽  
Stimulation Of

The responses of spinothalamic tract neurons were studied by extra- and intracellular recordings from the lumbosacral spinal cord in anesthetized rhesus monkeys (Macaca mulatta). The neurons were identified by antidromic activation from the contralateral diencephalon. They were then classified by the mildest form of mechanical stimulation applied to the ipsilateral hindlimb. The effects of electrical stimulation of the nerve(s) supplying the receptive field were investigated. Graded electrical stimulation revealed that the threshold responses of spinothalamic tract neurons excited by weak mechanical stimuli occurred when the largest afferent fibers were activated. On the other hand, neurons that required intense mechanical stimulation for their excitation tended to have higher thresholds to electrical stimulation. Some spinothalamic tract cells were shown to receive monosynaptic excitatory connections from peripheral nerve fibers, although polysynaptic connections may generally be more important. An input from unmyelinated afferent fibers was demonstrated. It is concluded the primate spinothalamic tract neurons receive a rich convergent input from a variety of cutaneous receptors. The experiments provide some evidence for the most likely types of receptors.

Effect of Electrical Stimulation of Dorsal and Ventral Spinal Cord Roots on the Cat’s Urinary Bladder

1974 ◽  
Vol 29 (5) ◽  
pp. 375-381 ◽  
Author(s):  
E. Eidelberg ◽  
E. Bors ◽  
C.M. Woodbury ◽  
A. Brigham
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Urinary Bladder ◽  
Ventral Spinal Cord ◽  
Stimulation Of

Transcutaneous electrical stimulation of urinary bladder in patients with spinal cord injuries

2008 ◽  
Vol 41 (3) ◽  
pp. 497-503 ◽  
Author(s):  
Krzysztof Radziszewski ◽  
Henryk Zielinski ◽  
Pawel Radziszewski ◽  
Rafal Swiecicki
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Urinary Bladder ◽  
Spinal Cord Injuries ◽  
Transcutaneous Electrical Stimulation ◽  
Stimulation Of

c-Fos expression in rat brain stem and spinal cord in response to activation of cardiac ischemia-sensitive afferent neurons and electrostimulatory modulation

2004 ◽  
Vol 287 (6) ◽  
pp. H2728-H2738 ◽  
Author(s):  
Fang Hua ◽  
Theresa Harrison ◽  
Chao Qin ◽  
Angela Reifsteck ◽  
Brian Ricketts ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Brain Stem ◽  
Nucleus Tractus Solitarius ◽  
Cardiac Ischemia ◽  
Afferent Neurons ◽  
Thoracic Spinal Cord ◽  
Thoracic Spinal ◽  
Afferent Fibers ◽  
Stimulation Of

The purpose of this study was to identify central neuronal sites activated by stimulation of cardiac ischemia-sensitive afferent neurons and determine whether electrical stimulation of left vagal afferent fibers modified the pattern of neuronal activation. Fos-like immunoreactivity (Fos-LI) was used as an index of neuronal activation in selected levels of cervical and thoracic spinal cord and brain stem. Adult Sprague-Dawley rats were anesthetized with urethane and underwent intrapericardial infusion of an “inflammatory exudate solution” (IES) containing algogenic substances that are released during ischemia (10 mM adenosine, bradykinin, prostaglandin E2, and 5-hydroxytryptamine) or occlusion of the left anterior descending coronary artery (CoAO) to activate cardiac ischemia-sensitive (nociceptive) afferent fibers. IES and CoAO increased Fos-LI above resting levels in dorsal horns in laminae I–V at C2 and T4 and in the caudal nucleus tractus solitarius. Dorsal rhizotomy virtually eliminated Fos-LI in the spinal cord as well as the brain stem. Neuromodulation of the ischemic signal by electrical stimulation of the central end of the left thoracic vagus excited neurons at the cervical and brain stem level but inhibited neurons at the thoracic spinal cord during IES or CoAO. These results suggest that stimulation of the left thoracic vagus excites descending inhibitory pathways. Inhibition at the thoracic spinal level that suppresses the ischemic (nociceptive) input signal may occur by a short-loop descending pathway via signals from cervical propriospinal circuits and/or a longer-loop descending pathway via signals from the nucleus tractus solitarius.

Periventricular gray inhibition of thoracic spinothalamic cells projecting to medial and lateral thalamus

1986 ◽  
Vol 55 (5) ◽  
pp. 1091-1103 ◽  
Author(s):  
W. S. Ammons ◽  
M. N. Girardot ◽  
R. D. Foreman
Keyword(s):  
Electrical Stimulation ◽  
Background Activity ◽  
Third Ventricle ◽  
Cell Activity ◽  
Receptive Fields ◽  
Descending Pathways ◽  
Descending Inhibition ◽  
Spinothalamic Tract ◽  
Before And After ◽  
Stimulation Of

Effects of electrical stimulation of the periventricular gray (PVG) on spinothalamic tract (STT) cell activity were determined in 19 anesthetized monkeys (Macaca fascicularis). Twenty-two STT cells projected to the ventral posterior lateral nucleus (L-STT cells), 11 to the medial thalamus (M-STT cells), and 9 to both thalamic regions (LM-STT cells). All cells had somatic receptive fields and responded to electrical stimulation of cardiopulmonary sympathetic afferent fibers. PVG stimulation inhibited activity of 41 of 42 STT cells. Degree of inhibition of background activity was related to intensity and frequency. Stimulus currents of 300 microA or less completely silenced background activity of most cells. Thresholds for stimulus current averaged 100 +/- 20 microA and were unrelated to cell projection site, laminar location, or type of somatic or visceral input. However, lowest thresholds were found when the PVG electrodes were located within 0.5 mm of the third ventricle in the dorsomedial hypothalamus or nucleus reuniens of the thalamus. PVG stimulation inhibited responses of 22 of 22 cells to intracardiac injections of bradykinin. Bradykinin (2 micrograms/kg) increased cell activity from 15 +/- 3 to 31 +/- 5 spikes/s (P less than 0.01), and PVG stimulation (380 +/- 40 microA) reduced activity to 9 +/- 3 spikes/s (P less than 0.001). PVG stimulation inhibited responses of 33 of 33 STT cells to noxious pinch of skin or skin and muscle and responses of 8 of 8 cells to hair movement. Degree of inhibition of cell responses to noxious pinch was not significantly different from inhibition of responses to bradykinin. Effects of PVG stimulation on activity of six STT cells were studied before and after bilateral lesions were made in the dorsolateral funiculus (DLF). In no case did the lesions abolish or attenuate inhibitory effects of PVG stimulation. These results suggest that PVG may participate in descending inhibition of STT cells including cells mediating cardiac pain. The descending pathways are not located in the DLF. Further, descending inhibitory systems modulate STT cells projecting to both medial and lateral thalamus.

Viscerosomatic neurons in the lower thoracic spinal cord of the cat: excitations and inhibitions evoked by splanchnic and somatic nerve volleys and by stimulation of brain stem nuclei

1986 ◽  
Vol 56 (5) ◽  
pp. 1411-1423 ◽  
Author(s):  
J. E. Tattersall ◽  
F. Cervero ◽  
B. M. Lumb
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Brain Stem ◽  
Chemical Stimulation ◽  
Descending Inhibition ◽  
Thoracic Spinal Cord ◽  
Homocysteic Acid ◽  
Afferent Fibers ◽  
Initial Excitation ◽  
Stimulation Of

Single-unit electrical activity has been recorded from 95 viscerosomatic neurons in the T9 and T11 segments of the cat's spinal cord. These neurons were excited by electrical and/or natural stimulation of visceral and somatic afferent fibers. The excitatory and inhibitory effects on these neurons of volleys in somatic and visceral afferent fibers and of electrical and chemical stimulation of the nucleus raphe magnus (NRM) and adjacent areas of the reticular formation (Ret. F.) have been studied. Electrical stimulation of the splanchnic nerve produced, after the initial excitation of the neurons, a period of inhibition lasting for up to 1 s. This inhibition reduced the responsiveness of the neurons to all inputs, somatic and visceral, and was still present after spinalization of the animals with cold block, which indicates a segmental organization of the inhibition. Electrical stimulation of afferent fibers within the somatic receptive field of the neurons produced, after the initial excitation, a period of inhibition similar to that induced by visceral afferent volleys. During this period of inhibition all inputs to the neurons were reduced. Reversible spinalization of the animals with cold block did not abolish this inhibition. On the basis of the effects of reversible spinalization on the visceral input to viscerosomatic neurons, two types of neurons were distinguished: 1) neurons whose visceral responses increased in the spinal state (neurons under tonic descending inhibition) and 2) neurons whose visceral responses were decreased or abolished in the spinal state (neurons subject to descending excitation). Neurons under tonic descending inhibition were inhibited by electrical stimulation of locations within the NRM and Ret. F. This inhibition lasted for less than 100 ms and could be evoked at intensities of stimulation of 100 microA or less. Neurons under descending excitation were also inhibited by electrical stimulation in the NRM and Ret. F. but, in addition, the inhibition was preceded by an excitation in 75% of these neurons. Chemical stimulation with DL-homocysteic acid (DLH) of locations within the NRM and Ret. F. was used to activate cell bodies, but not axons, located in these brain stem sites. The only effect observed following injections of DLH into the NRM and Ret. F. was inhibition of viscerosomatic neurons including those with descending excitation as well as those with descending inhibition.(ABSTRACT TRUNCATED AT 400 WORDS)

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