Extracellular K+ Activity and Slow Potential Changes in Spinal Cord and Medulla

1972 ◽  
Vol 50 (12) ◽  
pp. 1214-1217 ◽  
Author(s):  
K. Krnjević ◽  
Mary E. Morris
Keyword(s):  
Spinal Cord ◽  
Lumbar Spinal Cord ◽  
Cuneate Nucleus ◽  
Slow Potential ◽  
Afferent Fibers ◽  
Primary Afferent Fibers ◽  
Lumbar Spinal ◽  
Clear Increase ◽  
Stimulation Of ◽  
K Activity

In cats under Dial, repetitive stimulation of primary afferent fibers evokes a negative potential change in the cuneate nucleus or the dorsal horn of the lumbar spinal cord, which is associated with a clear increase in extracellular K+ activity, recorded by K+ selective microelectrodes.

ATP P2× Receptors and Sensory Synaptic Transmission Between Primary Afferent Fibers and Spinal Dorsal Horn Neurons in Rats

1998 ◽  
Vol 80 (6) ◽  
pp. 3356-3360 ◽  
Author(s):  
Ping Li ◽  
Amelita A. Calejesan ◽  
Min Zhuo
Keyword(s):  
Spinal Cord ◽  
Synaptic Transmission ◽  
Dorsal Horn ◽  
Lumbar Spinal Cord ◽  
Superficial Dorsal Horn ◽  
Primary Afferent ◽  
Dorsal Horn Neurons ◽  
Afferent Fibers ◽  
Primary Afferent Fibers ◽  
Lumbar Spinal

Li, Ping, Amelita A. Calean, and Min Zhuo. ATP P2× receptors and sensory synaptic transmission between primary afferent fibers and spinal dorsal horn neurons in rats. J. Neurophysiol. 80: 3356–3360, 1998. Glutamate is a major fast transmitter between primary afferent fibers and dorsal horn neurons in the spinal cord. Recent evidence indicates that ATP acts as another fast transmitter at the rat cervical spinal cord and is proposed to serve as a transmitter for nociception and pain. Sensory synaptic transmission between dorsal root afferent fibers and neurons in the superficial dorsal horn of the lumbar spinal cord were examined by whole cell patch-clamp recording techniques. Experiments were designed to test if ATP could serve as a transmitter at the lumbar spinal cord. Monosynaptic excitatory postsynaptic currents (EPSCs) were completely abolished after the blockade of both glutamatergic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate and N-methyl-d-aspartate receptors. No residual current was detected, indicating that glutamate but not ATP is a fast transmitter at the dorsal horn of the lumbar spinal cord. Pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS), a selective P2× receptor antagonist, produced an inhibitory modulatory effect on fast EPSCs and altered responses to paired-pulse stimulation, suggesting the involvement of a presynaptic mechanism. Intrathecal administration of PPADS did not produce any antinociceptive effect in two different types of behavioral nociceptive tests. The present results suggest that ATP P2×2 receptors modulate excitatory synaptic transmission in the superficial dorsal horn of the lumbar spinal cord by a presynaptic mechanism, and such a mechanism does not play an important role in behavioral responses to noxious heating. The involvement of other P2× subtype receptors, which is are less sensitive to PPADS, in acute nociceptive modulation and persistent pain remains to be investigated.

scholarly journals Co-injection of wheat germ agglutinin-HRP and choleragenoid-HRP into the sciatic nerve of the rat blocks transganglionic transport.

1995 ◽  
Vol 43 (5) ◽  
pp. 489-495 ◽  
Author(s):  
H Liu ◽  
I J Llewellyn-Smith ◽  
A I Basbaum
Keyword(s):  
Spinal Cord ◽  
Sciatic Nerve ◽  
Motor Neurons ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Lumbar Spinal Cord ◽  
Retrograde Labeling ◽  
Afferent Fibers ◽  
Primary Afferent Fibers ◽  
Lumbar Spinal

We report on the surprising loss of transganglionic and retrograde labeling in the spinal cord of the rat after co-injection of the tracers wheat germ agglutinin-HRP (WGA-HRP) and choleragenoid toxin-HRP (CTB-HRP) into the sciatic nerve. Injection of WGA-HRP alone produced a pattern of transganglionic label consistent with transport by small-diameter primary afferent fibers. Small cell bodies were labeled in the ipsilateral dorsal root ganglion (DRG) and there was dense terminal labeling in the superficial dorsal horn of the lumbar spinal cord. Injection of CTB-HRP alone produced a pattern of transganglionic labeling consistent with transport by large-diameter primary afferent fibers. Large cell bodies were labeled in the DRG and there was dense terminal labeling in the nucleus proprius (Laminae III-V) in the spinal cord. CTB-HRP also produced extensive retrograde labeling of ventral horn motor neurons. When the two tracers were co-injected, we found few labeled cells in the ipsilateral DRG and there was almost complete loss of transganglionic terminal labeling in the lumbar spinal cord. Retrograde labeling of motor neurons was also significantly reduced. Even when one of the tracers (e.g., WGA-HRP) was injected 24 hr after and up to 10 mm proximal to the site of the first tracer (e.g., CTB-HRP), an inhibitory interaction was detected. The labeling pattern was always characteristic of the first tracer injected.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Locomotor-Activated Neurons of the Cat. I. Serotonergic Innervation and Co-Localization of 5-HT7, 5-HT2A, and 5-HT1A Receptors in the Thoraco-Lumbar Spinal Cord

2009 ◽  
Vol 102 (3) ◽  
pp. 1560-1576 ◽  
Author(s):  
Brian R. Noga ◽  
Dawn M. G. Johnson ◽  
Mirta I. Riesgo ◽  
Alberto Pinzon
Keyword(s):  
Spinal Cord ◽  
Lumbar Spinal Cord ◽  
Lumbar Spinal ◽  
Rostrocaudal Gradient ◽  
Activity Dependent ◽  
Decerebrate Cats ◽  
Intermediolateral Nucleus ◽  
Serotonergic Modulation ◽  
Stimulation Of ◽  
Serotonergic Innervation

Monoamines are strong modulators and/or activators of spinal locomotor networks. Thus monoaminergic fibers likely contact neurons involved in generating locomotion. The aim of the present study was to investigate the serotonergic innervation of locomotor-activated neurons within the thoraco-lumbar spinal cord following induction of hindlimb locomotion. This was determined by immunohistochemical co-localization of serotonin (5-HT) fibers or 5-HT7/5-HT2A/5-HT1A receptors with cells expressing the activity-dependent marker c-fos. Experiments were performed on paralyzed, decerebrate cats in which locomotion was induced by electrical stimulation of the mesencephalic locomotor region. Abundant c-fos immunoreactive cells were observed in laminae VII and VIII throughout the thoraco-lumbar segments of locomotor animals. Control sections from the same segments showed significantly fewer labeled neurons, mostly within the dorsal horn. Multiple serotonergic boutons were found in close apposition to the majority (80–100%) of locomotor cells, which were most abundant in lumbar segments L3–7. 5-HT7 receptor immunoreactivity was observed on cells across the thoraco-lumbar segments (T7–L7), in a dorsoventral gradient. Most locomotor-activated cells co-localized with 5-HT7, 5-HT2A, and 5-HT1A receptors, with largest numbers in laminae VII and VIII. Co-localization of c-fos and 5-HT7 receptor was highest in the L5–L7 segments (>90%) and decreased rostrally (to ∼50%) due to the absence of receptors on cells within the intermediolateral nucleus. In contrast, 60–80 and 35–80% of c-fos immunoreactive cells stained positive for 5-HT2A and 5-HT1A receptors, respectively, with no rostrocaudal gradient. These results indicate that serotonergic modulation of locomotion likely involves 5-HT7/5-HT2A/5-HT1A receptors located on the soma and proximal dendrites of serotonergic-innervated locomotor-activated neurons within laminae VII and VIII of thoraco-lumbar segments.

N-Methyl-D-Aspartate Antagonist Inhibits NR-1 Subunit Phosphorylation of the Spinal N-Methyl-D-Aspartate Receptor Induced by Low Frequency Electroacupuncture

2007 ◽  
Vol 35 (06) ◽  
pp. 987-993 ◽  
Author(s):  
Byeol-Rim Kang ◽  
Chang-Beohm Ahn ◽  
Byung-Tae Choi
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Peripheral Nerves ◽  
Intrathecal Injection ◽  
Low Frequency ◽  
Serine Phosphorylation ◽  
Lumbar Spinal Cord ◽  
Aspartate Receptor ◽  
Lumbar Spinal ◽  
Stimulation Of

We investigated whether the 2 Hz electroacupuncture (EA) analgesia is associated with phosphorylation of N-methyl-D-aspartate receptor (NMDAR) NR-1 subunits and NMDAR antagonism in the lumbar spinal cord of rats. EA stimulation produced an increase of serine phosphorylation of NMDAR NR-1 subunits in the spinal cord as compared with normal conditions. However, the intrathecal injection of NMDAR antagonist D-2-amino-5-phosphonopentanoic acid significantly prevented serine phosphorylation of NMDAR NR-1 subunits induced by EA stimulation in the dorsal horn of spinal cord. These results indicate that EA analgesia by stimulation of peripheral nerves may be involved in an increase of NR-1 serine phosphorylation in the dorsal horn of the spinal cord.

scholarly journals Regulation of respiration during electrical stimulation of the lumbar spinal cord in humans

2020 ◽  
Vol 1 (2) ◽  
pp. 108-114
Author(s):  
Tatyana R. Moshonkina ◽  
Natalia A. Scherbakova ◽  
Sergey A. Moiseev ◽  
Arina V. Minyaeva ◽  
Yuri P. Gerasimenko
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Lumbar Spinal Cord ◽  
Regulation Of Respiration ◽  
Lumbar Spinal ◽  
Stimulation Of

Role of peripheral tissue receptors in stimulation of ventilation by 2,4-dinitrophenol

1979 ◽  
Vol 47 (5) ◽  
pp. 1066-1073 ◽  
Author(s):  
S. Levine
Keyword(s):  
Spinal Cord ◽  
Lumbar Spinal Cord ◽  
Afferent Pathways ◽  
Lumbar Level ◽  
Complete Transection ◽  
Group I ◽  
Group Ii ◽  
Lumbar Spinal ◽  
Quantitative Contribution ◽  
Stimulation Of

Previous workers have demonstrated that hindlimb receptors can mediate some portion of the increase in VE elicited by 2,4-dinitrophenol (DNP). Liang and Hood have recently demonstrated that these hindlimb receptors communicate with the respiratory center via afferent pathways of the lumbar spinal cord. Accordingly, to determine the quantitative contribution of these hindlimb receptors to increases in VE elicited by DNP (4 mg/kg), we compared two groups of animals with respect to ventilatory, metabolic, and thermal responses elicited by this drug. Group I animals underwent complete transection of the spinal cord at the first lumbar level, whereas the spinal cord in Group II animals remained intact. Our results indicate that Group I and Group II animals did not differ with respect to increases in VE, VO2, and rectal temperature elicited by DNP. These results suggest that hindlimb receptors do not play an obligatory role in mediating increases in VE elicited by DNP. Therefore, these observations raise the possibility that multiple afferent pathways may exist for stimulation of VE by DNP.

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