Substance P, morphine and methionine-enkephalin: Effects on spontaneous and evoked neuronal firing in the nucleus reticularis gigantocellularis of the rat

Haigler, Henry J.; Spring, Denise D.

doi:10.1016/0014-2999(80)90009-6

Cited by 14 publications

(3 citation statements)

References 24 publications

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“…Pharmacological study has shown that injection of substance P into the NMC generates brief episodes of stepping activity (5-10 sec) with long latency (5-10 min) in the decerebrate rat [226]. Iontophoretic application of substance P into the NMC increased neuronal firing, which mimicked noxious stimuli (foot pinch) induced firing [150]. However, the nociceptive response was unaltered by application of substance P into the NMC [150].…”

Section: Substance Pmentioning

confidence: 96%

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Sensory-Motor Integration in the Medial Medulla

Lai¹,

Siegel²

2005

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The rostromedial medulla, including the nucleus gigantocellularis (NGC) and magnocellularis (NMC), plays a role as a relay nucleus for both the sensory and motor systems. The NGC/NMC is important in the modulation of somatic and visceral activities. Electrophysiological and pharmacological studies have shown that the NGC/NMC is involved in nociception, locomotion, regulation of basal muscle tone, sleep, as well as cardiovascular and pulmonary activities. Pharmacological and electrical stimulation of the NGC/NMC can produce opposite effects on physiological functions: analgesia or hyperalgesia, and suppression or facilitation of motor activity, depending on the subgroups of neurons activated and the states of the sleep-wake cycle at the time of stimulation. Sensory inputs including noxious and innocuous stimuli converge on the NGC/NMC. The NGC/NMC also plays a role as a relay nucleus, which sends sensory information to the higher centers. The NGC/NMC receives projections from the supra-bulbar motor facilitatory and inhibitory areas, and plays an important role in the regulation of motor activity. Pharmacologically, neurons in the NGC/NMC contribute to opioid, glutamate, GABA, acetylcholine, dopamine, substance P, neurotensin, hypocretin (orexin), and cannabinoid mediated sensory and motor activities, as well as cardiovascular and pulmonary functions. In this review, we will discuss the neuronal morphology, physiological functions and pharmacological characterization of the rostromedial medulla. We will consider the evidence that dysfunction of the NGC/NMC is a factor in a number of neurological diseases, including Parkinson's disease, restless legs syndrome, periodic leg movement, REM sleep behavior disorder, amyotrophic lateral sclerosis and narcolepsy. INTRODUNTIONThe medullary reticular formation is traditionally segregated into the medial somatic-and lateral visceralrelated areas. However, somatic and autonomic activities are well coordinated. For example, cardiovascular-respiratory changes are correlated with somatic sensory-motor activity during exercise. Coordination of somatic and autonomic activity can result from interconnections between somatic and autonomic control structures, as well as interactions within nuclei, which are involved in both somatic and autonomic activities. The rostromedial medulla (RMM) is one of the areas of the central nervous system (CNS) that is involved in both somatic and autonomic regulation. However, the RMM has traditionally been considered as a somatic nociceptive and a motor control area. The autonomic role of the RMM has received little attention, although Bach [22] demonstrated that the activation of RMM causes changes in cardiovascular and respiratory activity, as well as the facilitation and inhibition of somatic motor activity in 1952. Therefore, we will discuss the functional aspects of RMM in the modulation of both somatic and autonomic systems in this review. Section 1 will focus on the morphology of the RMM, and the anatomical link between RMM and the other areas...

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Section: Substance Pmentioning

confidence: 96%

“…Iontophoretic application of substance P into the NMC increased neuronal firing, which mimicked noxious stimuli (foot pinch) induced firing [150]. However, the nociceptive response was unaltered by application of substance P into the NMC [150].…”

Section: Substance Pmentioning

confidence: 97%

Sensory-Motor Integration in the Medial Medulla

Lai¹,

Siegel²

2005

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“…Some information is presently available to support a role for this opioid in the modulation of the interactive effect of noxious and hypertensive stimuli on the respon siveness of NRGC neurons. First, the endogenous opioids, including the enkephalins, are intimately related to the central regulation of nociception [4,16,29,30,38] and circulation [1,27,28,30,31,36], Second, results from our laboratory and others have further shown that the NRGC is actively involved in the antinociceptive [8,17,22,33] and cardiovascular suppressive [19,37] ac tions of morphine and the enkephalins. Third, opioid receptors [2] and enkephalinergic fiber terminals [18,32,35] have been identified in the medullary reticular forma tion, including the NRGC.…”

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confidence: 98%

Further Characterization of Nociception-Related and Arterial Pressure-Related Neuronal Responses in the Nucleus Reticularis Gigantocellularis of the Rat

Kuo¹,

Yang²,

Chan³

et al. 1996

J Biomed Sci

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The present study was undertaken to further characterize the nucleus reticularis gigantocellularis (NRGC) of the medulla oblongata in the central processing of nociceptive and cardiovascular signals, and its modulation by metenkephalin. In Sprague-Dawley rats anesthetized with pentobarbital sodium, we found that all 125 spontaneously active NRGC neurons that responded to noxious stimuli (tail clamp) also exhibited arterial pressure-relatedness. Forty neurons additionally manifested cardiac periodicity that persisted even during nociceptive responses. While maintaining their cardiovascular responsive characteristics, the nociception-related NRGC neuronal activity was blocked, naloxone-reversibly (0.5 mg/kg, i.v.), by morphine (5 mg/kg, i.v.). Microiontophoretically applied met-enkephalin suppressed the responsiveness of NRGC neurons to individually delivered tail clamp or transient hypertension induced by phenylephrine (5 μg/kg. i.v.). Interestingly, in NRGC neurons that manifested both nociception and arterial pressure relatedness, the preferential reduction in the response to noxious stimuli upon simultaneous elevation in systemic arterial pressure was reversed to one that favored nociception in the presence of met-enkephalin. All actions of met-enkephalin were discemibly blocked by the opioid receptor antagonist, naloxone. Our results suggest that individual NRGC neurons may participate in the processing of both nociceptive and cardiovascular information, or in the coordination of the necessary circulatory supports during nociception. In addition, neuropeptides such as met-enkephalin may exert differential modulation on neuronal responsiveness according to the prevailing physiologic status of the animal. They also showed that NRGC may be a central integrator for pain and cardiovascularrelated functions.

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Further characterization of nociception-related and arterial pressure-related neuronal responses in the nucleus reticularis gigantocellularis of the rat

Kuo¹,

Yang²,

Chan

et al. 1996

J Biomed Sci

View full text Add to dashboard Cite

The present study was undertaken to further characterize the nucleus reticularis gigantocellularis (NRGC) of the medulla oblongata in the central processing of nociceptive and cardiovascular signals, and its modulation by met-enkephalin. In Sprague-Dawley rats anesthetized with pentobarbital sodium, we found that all 125 spontaneously active NRGC neurons that responded to noxious stimuli (tail clamp) also exhibited arterial pressure-relatedness. Forty neurons additionally manifested cardiac periodicity that persisted even during nociceptive responses. While maintaining their cardiovascular responsive characteristics, the nociception-related NRGC neuronal activity was blocked, naloxone-reversibly (0.5 mg/kg, i.v.), by morphine (5 mg/kg, i.v.). Microiontophoretically applied met-enkephalin suppressed the responsiveness of NRGC neurons to individually delivered tail clamp or transient hypertension induced by phenylephrine (5 &mgr;g/kg, i.v.). Interestingly, in NRGC neurons that manifested both nociception and arterial pressure relatedness, the preferential reduction in the response to noxious stimuli upon simultaneous elevation in systemic arterial pressure was reversed to one that favored nociception in the presence of met-enkephalin. All actions of met-enkephalin were discernibly blocked by the opioid receptor antagonist, naloxone. Our results suggest that individual NRGC neurons may participate in the processing of both nociceptive and cardiovascular information, or in the coordination of the necessary circulatory supports during nociception. In addition, neuropeptides such as met-enkephalin may exert differential modulation on neuronal responsiveness according to the prevailing physiologic status of the animal. They also showed that NRGC may be a central integrator for pain and cardiovascular-related functions. Copyright 1996 S. Karger AG, Basel

show abstract

Substance P, morphine and methionine-enkephalin: Effects on spontaneous and evoked neuronal firing in the nucleus reticularis gigantocellularis of the rat

Cited by 14 publications

References 24 publications

Sensory-Motor Integration in the Medial Medulla

Sensory-Motor Integration in the Medial Medulla

Further Characterization of Nociception-Related and Arterial Pressure-Related Neuronal Responses in the Nucleus Reticularis Gigantocellularis of the Rat

Further characterization of nociception-related and arterial pressure-related neuronal responses in the nucleus reticularis gigantocellularis of the rat

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