The involvement of substance P and neurokinin-1 receptors in the responses of rat dorsal horn neurons to noxious but not to innocuous mechanical stimuli applied to the knee joint

1994 ◽  
Vol 666 (2) ◽  
pp. 207-215 ◽  
Author(s):  
Volker Neugebauer ◽  
Hans-Georg Schaible ◽  
Frank Weiretter ◽  
Ulrike Freudenberger
Keyword(s):  
Substance P ◽  
Knee Joint ◽  
Dorsal Horn ◽  
Mechanical Stimuli ◽  
Dorsal Horn Neurons ◽  
Neurokinin 1

Involvement of substance P and neurokinin-1 receptors in the hyperexcitability of dorsal horn neurons during development of acute arthritis in rat's knee joint

1995 ◽  
Vol 73 (4) ◽  
pp. 1574-1583 ◽  
Author(s):  
V. Neugebauer ◽  
F. Weiretter ◽  
H. G. Schaible
Keyword(s):  
Substance P ◽  
Knee Joint ◽  
Intravenous Administration ◽  
Initial Period ◽  
Receptive Fields ◽  
Neurokinin A ◽  
Mechanical Stimuli ◽  
Similar Reduction ◽  
Spinal Cord Neurons ◽  
Neurokinin 1

1. In anesthetized rats we studied the involvement of substance P and neurokinin-1 receptors in the generation and maintenance of hyperexcitability in spinal cord neurons, which develops in the course of an acute experimental inflammation in the knee. In all experiments one nociceptive neuron with knee input was identified, and the responses to mechanical stimuli and the receptive fields were monitored before and after induction of inflammation by the injections of kaolin and carrageenan into the knee joint. In 18 experiments either the specific antagonist at the neurokinin-1 receptor ionophoretically close to the neuron or intravenously during the injections of kaolin and carrageenan and in three periods of 15 min in the 95 min postkaolin (initial period of inflammation) to test their effects on the development of hyperexcitability. CP96,345 and CP96,344 were also administered after full development of inflammation to study their effects in hyperexcitable neurons. CP96,345 was ejected at currents that reduced or completely suppressed the effects of ionophoretically administered substance P but not those of neurokinin A, the agonist at neurokinin-2 receptors. 2. After the injections of kaolin and carrageenan into the knee joint, untreated control neurons (n = 8) developed hyperexcitability consisting of enhanced responses to noxious stimuli applied to the injected knee and the noninjected ankle, of an enhancement or induction of the responses to innocuous pressure applied to the joints and of an expansion of the receptive field. In eight neurons treated with ionophoretic administration of CP96,345 during the induction and initial period of inflammation, the development of hyperexcitability was not completely prevented but significantly attenuated. In comparison with the changes in the control neurons, the development of hyperexcitability was markedly reduced from the 2nd h up to 5 h postkaolin, but it was barely affected by CP96,345 within the 1st h postkaolin. Intravenous administration of CP96,345 in the initial period of inflammation produced a similar reduction of the development of hyperexcitability in another four neurons. The ionophoretic application of CP96,344 during and after induction of inflammation did not apparently impair the development of hyperexcitability (n = 6 neurons). 3. After development of inflammation and hyperexcitability, both the responses to innocuous and noxious pressure applied to the inflamed knee joint were reduced by the ionophoretic (n = 16 neurons) and intravenous administration (n = 9 neurons) of CP96,345 (tested 4.5-8 h postkaolin). Similarly, the responses to innocuous and noxious pressure applied to the noninflamed ankle were reduced by CP96,345 after inflammation had developed in the knee joint.(ABSTRACT TRUNCATED AT 400 WORDS)

Light- and electron-microscopic evidence of costoring of immunoreactive enkephalins and substance P in dorsal horn neurons of rat

1988 ◽  
Vol 253 (2) ◽  
Author(s):  
Shinsuke Katoh ◽  
Setsuji Hisano ◽  
Hitoshi Kawano ◽  
Yasuaki Kagotani ◽  
Shigeo Daikoku
Keyword(s):  
Substance P ◽  
Dorsal Horn ◽  
Electron Microscopic ◽  
Dorsal Horn Neurons ◽  
Microscopic Evidence

scholarly journals Effects of General Anesthetics on Substance P Release and c-Fos Expression in the Spinal Dorsal Horn

2013 ◽  
Vol 119 (2) ◽  
pp. 433-442 ◽  
Author(s):  
Toshifumi Takasusuki ◽  
Shigeki Yamaguchi ◽  
Shinsuke Hamaguchi ◽  
Tony L. Yaksh
Keyword(s):  
Nitrous Oxide ◽  
Substance P ◽  
Dorsal Horn ◽  
Receptor Internalization ◽  
General Anesthetics ◽  
Neurokinin 1 Receptor ◽  
P Release ◽  
Fos Expression ◽  
Neurokinin 1 ◽  
Substance P Release

Abstract Background: The authors examined in vivo the effects of general anesthetics on evoked substance P release (primary afferent excitability) and c-Fos expression (neuronal activation) in superficial dorsal horn. Methods: Rats received saline, propofol (100 mg/kg), pentobarbital (50 mg/kg), isoflurane (2 minimum alveolar concentration), nitrous oxide (66%), or fentanyl (30 μg/kg). During anesthesia, rats received intraplantar 5% formalin (50 μl) to left hind paw. Ten minutes later, rats underwent transcardial perfusion with 4% paraformaldehyde. Substance P release from small primary afferents was assessed by incidence of neurokinin 1 receptor internalization in the superficial dorsal horn. In separate studies, rats were sacrificed after 2 h and c-Fos expression measured. Results: Intraplantar formalin-induced robust neurokinin 1 receptor internalization in ipsilateral dorsal horn (ipsilateral: 54 ± 6% [mean ± SEM], contralateral: 12 ± 2%; P < 0.05; n = 4). Fentanyl, but not propofol, pentobarbital, isoflurane, nor nitrous oxide alone inhibited neurokinin 1 receptor internalization. However, 2 minimum alveolar concentration isoflurane + nitrous oxide reduced neurokinin 1 receptor internalization (27 ± 3%; P < 0.05; n = 5). All agents reduced c-Fos expression (control: 34 ± 4, fentanyl: 8 ± 2, isoflurane: 12 ± 3, nitrous oxide: 11 ± 2, isoflurane + nitrous oxide: 12 ± 1, pentobarbital: 11 ± 2, propofol: 13 ± 3; P < 0.05; n = 3). Conclusion: General anesthetics at anesthetic concentrations block spinal neuron activation through a mechanism that is independent of an effect on small primary afferent peptide release. The effect of fentanyl alone and the synergistic effect of isoflurane and nitrous oxide on substance P release suggest a correlative rationale for the therapeutic use of these anesthetic protocols by blocking nociceptive afferent transmitter release and preventing the initiation of cascade, which is immediately postsynaptic to the primary afferent.

Spinal substance P release in vivo during the induction of long-term potentiation in dorsal horn neurons

Pain ◽  
2002 ◽  
Vol 96 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Abdullahi Warsame Afrah ◽  
Atle Fiskå ◽  
Johannes Gjerstad ◽  
Henrik Gustafsson ◽  
Arne Tjølsen ◽  
...  
Keyword(s):  
Substance P ◽  
Dorsal Horn ◽  
Long Term Potentiation ◽  
Dorsal Horn Neurons ◽  
P Release ◽  
Term Potentiation ◽  
Substance P Release

scholarly journals Electrophysiological Changes in Adult Rat Dorsal Horn Neurons After Neonatal Peripheral Inflammation

2003 ◽  
Vol 90 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Yuan Bo Peng ◽  
Qing Dong Ling ◽  
M. A. Ruda ◽  
Daniel R. Kenshalo
Keyword(s):  
Spinal Cord ◽  
Receptive Field ◽  
Dorsal Horn ◽  
Dynamic Range ◽  
High Threshold ◽  
Peripheral Inflammation ◽  
Mechanical Stimuli ◽  
Neonatal Rats ◽  
Adult Rats ◽  
Dorsal Horn Neurons

Neonatal peripheral inflammation has been shown to produce profound anatomical changes in the dorsal horn of adult rats. In this study, we explored whether parallel physiological changes exist. Neonatal rats were injected with complete Freund's adjuvant (CFA) into the left hind paw. At 8–10 wk of age, single dorsal horn neurons were recorded in response to graded intensities of mechanical stimuli delivered to the receptive field. In addition, cord dorsum potentials, produced by electrical stimuli delivered to the left sciatic nerve at 2.5× threshold, were recorded bilaterally from L2 to S3. There were significant increases in background activity and responses to brush and pinch in neonatal rats that were treated with CFA, as compared with control rats. Further analysis showed similar significant changes when dorsal horn neurons were categorized into wide dynamic range (WDR), high-threshold (HT), and low-threshold (LT) groups. The receptive field was significantly larger in neonatally treated rats as compared with control rats. Additionally, there was a significant increase in the response to a 49°C heat stimulus in neonatally treated rats as compared with control rats. There was also a trend for the amplitudes of N1, N2, and P waves of the cord dorsum potential to increase and latencies to decrease in neonatally treated rats, but no significant differences were detected between different levels of the spinal cord (L2 to S3). These data further support the notion that anatomical and physiological plasticity changes occurred in the spinal cord following early neonatal CFA treatment.

A comparative study of the changes in receptive-field properties of multireceptive and nocireceptive rat dorsal horn neurons following noxious mechanical stimulation

1989 ◽  
Vol 62 (4) ◽  
pp. 854-863 ◽  
Author(s):  
J. M. Laird ◽  
F. Cervero
Keyword(s):  
Dorsal Horn ◽  
Mechanical Stimulation ◽  
Receptive Fields ◽  
Mechanical Stimulus ◽  
Mechanical Stimuli ◽  
Dorsal Horn Neurons ◽  
Mechanical Threshold ◽  
Before And After ◽  
Low Threshold ◽  
Noxious Mechanical Stimulation

1. Single-unit electrical activity has been recorded from 42 dorsal horn neurons in the sacral segments of the rat's spinal cord. The sample consisted of 20 multireceptive (class 2) cells with both A- and C-fiber inputs and 22 nocireceptive (class 3) cells. All neurons had cutaneous receptive fields (RFs) on the tail. 2. The RF sizes of the cells and their response thresholds to mechanical stimulation of the skin were determined before and after each of a series of 2-min noxious mechanical stimuli. Up to five such stimuli were delivered at intervals ranging from 10 to 60 min. In most cases, only one cell per animal was tested. 3. The majority of neurons were tested in barbiturate-anesthetized animals. However, to test whether or not this anesthetic influenced the results obtained, experiments were also performed in halothane-anesthetized and decerebrate-spinal preparations. The results from these experiments are considered separately. 4. All of the neurons responded vigorously to the first noxious pinch stimulus and all but one to the rest of the stimuli in the series. The responses of the neurons varied from stimulus to stimulus, but there were no detectable trends in the two groups of cells. 5. The RFs of the class 2 cells showed large increases (624.3 +/- 175.8 mm2, mean +/- SE) after the application of the pinch stimuli. The RFs of the class 3 neurons, which were initially smaller than those of the class 2 cells, either did not increase in size or showed very small increases after the pinch stimuli (38.3 +/- 11.95 mm2, mean +/- SE). 6. Some cells in both groups (6/10 class 2 cells and 7/16 class 3 cells) showed a decrease in mechanical threshold as a result of the noxious mechanical stimulus, but none of the class 3 cells' thresholds dropped below 20 mN into the low-threshold range. 7. The results obtained in the halothane-anesthetized and decerebrate-spinal animals were very similar to those seen in the barbiturate-anesthetized experiments, with the exception that in the decerebrate-spinal animals, the RFs of the class 2 cells were initially larger and showed only small increases.(ABSTRACT TRUNCATED AT 400 WORDS)

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