Depolarization of group II muscle afferents by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

Riddell, John S.; Jankowska, E.; Eide, Erling

doi:10.1113/jphysiol.1993.sp019538

Cited by 49 publications

(54 citation statements)

References 43 publications

(58 reference statements)

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“…There are also indications that neuronal systems mediating presynaptic inhibition are activated by the conditioning stimuli applied in the LC/SC and raphe nuclei since such stimuli produce depolarization of the terminals of group II afferents in the midlumbar segments (Riddell, Jankowska & Eide, 1993). It is not clear at present whether monoaminergic or non-monoaminergic systems are involved in these actions (see Discussion of Riddell et al 1992).…”

Section: The Site Of the Depressive Actionsmentioning

confidence: 99%

Gating of transmission to motoneurones by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

Jankowska

Riddell

Skoog

et al. 1993

The Journal of Physiology

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SUMMARY1. Neuronal systems activated by stimulation in the region of the locus coeruleus/subcoeruleus (LC/SC) and raphe nuclei have previously been shown to depress transmission from group II muscle afferents in regions of the midlumbar spinal segments in which premotor interneurones are located. The aim of the present investigation was to determine the extent to which such depression is paralleled by depression of the reflex actions of group II afferents on motoneurones.2. The effects of short trains of conditioning electrical stimuli applied within the LC/SC and raphe nuclei were examined on postsynaptic potentials (PSPs) evoked by group I and group II muscle afferents in hindlimb motoneurones. The effects were examined over a wide range of conditioning-test intervals but particular emphasis was placed on the effects produced at long intervals (> 100 ms) since such effects are more likely to be mediated by the descending noradrenergic and serotonergic neurones of the LC/SC and raphe nuclei which are of slow conduction velocity. In addition, conditioning stimuli alone evoked PSPs in motoneurones (with latencies of 7-15 ms and a duration of 50-80 ms) and effects evoked at short conditioning-test intervals might therefore have been secondary to changes in motoneurone membrane properties.3. At conditioning-test intervals between 100 and 350 ms synaptic actions of group II origin were strongly and consistently depressed. Both EPSPs and IPSPs were affected, two-thirds of those tested being reduced in amplitude by 50 % or more. A similar depression was exerted on PSPs evoked from the quadriceps and deep peroneal nerves mediated predominantly by interneurones located in the midlumbar segments and on PSPs evoked from the hamstring and triceps surae nerves mediated by interneurones located in more caudal segments. It is thus concluded that neuronal systems activated by stimuli applied in the LC/SC and raphe nuclei are capable of gating transmission in all those interneuronal pathways which mediate the reflex actions of group II afferents on motoneurones in anaesthetized animals.

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Section: The Site Of the Depressive Actionsmentioning

confidence: 99%

Gating of transmission to motoneurones by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

Jankowska

Riddell

Skoog

et al. 1993

The Journal of Physiology

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“…For example, Jankowska and coworkers have demonstrated that 5-HT and raphe-spinal stimulation can exert a dierential control over primary aerent-evoked responses of dierent modalities (e.g. Riddell et al, 1993;Jankowska et al, 1997;. A third limitation to this study is that the DDH is functionally heterogeneous, yet all dorsal horn neurons were treated here as a single population.…”

Section: Limitations Of the Experimental Approachmentioning

confidence: 99%

Pharmacological characterization of serotonin receptor subtypes modulating primary afferent input to deep dorsal horn neurons in the neonatal rat

Garraway

Hochman

2001

British J Pharmacology

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1 Spinal cord slices and whole-cell patch clamp recordings were used to investigate the eects of serotonergic receptor ligands on dorsal root-evoked synaptic responses in deep dorsal horn (DDH) neurons of the neonatal rat at postnatal days (P) 3 ± 6 and P10 ± 14. 2 Bath applied 5-hydroxytryptamine (5-HT) potently depressed synaptic responses in most neurons. Similarly, the 5-HT 1/7 receptor agonist, 5-carboxamidotryptamine (5-CT) depressed synaptic responses. This action was probably mediated by 5-HT 1A receptor activation, since it occurred in the presence of the 5-HT 7 receptor antagonist clozapine and was not observed in the presence of NAN-190, a 5-HT 1A receptor antagonist. In the absence of any agonist, 5-HT 1A receptor antagonists often facilitated synaptic responses, suggesting that there is sucient endogenous 5-HT to tonically activate 5-HT 1A receptors. 3 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), the 5-HT 1A/7 receptor agonist, facilitated synaptic responses, an action probably mediated by 5-HT 7 receptors, since the facilitation could be reversed by subsequent application of the 5-HT 7 receptor antagonist clozapine. 4 Agonists for the 5-HT 1B , 5-HT 2 and 5-HT 3 receptors exerted only modest modulatory actions. 5 A pharmacological analysis of the depression evoked by 5-HT suggested an action partly mediated by 5-HT 1A receptor activation, since antagonism of the 5-HT 1A receptor with NAN-190 or WAY-100635 partly reversed 5-HT-evoked depression. In comparison, 5-HT 7 receptor activation could account for much of the 5-HT-evoked facilitation. 6 We conclude that 5-HT is capable of modulating sensory input onto DDH neurons via several receptor subtypes, producing both facilitatory and depressant actions. Also, the actions of most receptor ligands on the evoked responses were similar within the ®rst 2 postnatal weeks.

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“…There is considerable information available on the sources of PAD of cutaneous afferents (e.g. Schmidt, 1971;Baldissera, Hultborn & Illert, 1981), group I (see Baldissera et al 1981;Rudomin, 1990) and group II muscle afferents (Harrison & Jankowska, 1989;Riddell, Jankowska & Eide, 1993), interosseous and joint fibres (Jankowska, Riddell & McCrea, 1993), and C fibres (Woolf & Fitzgerald, 1982). In contrast, less is known about sources of PAD of SPud afferents.…”

Section: Observations) During Micturition In Catsmentioning

confidence: 99%

Primary afferent depolarization of cat pudendal afferents during micturition and segmental afferent stimulation.

Angel¹,

Fyda²,

McCrea³

et al. 1994

The Journal of Physiology

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1. This investigation examined primary afferent depolarization (PAD) of perineal afferents during micturition and evoked by electrical stimulation of perineal, hindlimb cutaneous and muscle-nerves. PAD was inferred from changes in excitability of spinal terminals of single afferents in decerebrate and chloralose-anaesthetized paralysed male cats. Observations were made on perineal afferent fibres travelling in the sensory branch of the pudendal (SPud) and superficial perineal (SPeri) nerves.2. Micturition was evoked by distension of the bladder and excitability changes were measured in twenty-seven SPud afferents. In ten afferents, there was evidence of PAD during micturition. The time course of PAD was similar to the period of decreased activity in sphincter muscle efferents during micturition. In four afferents, there was decreased excitability during voiding that was interpreted as removal of tonic PAD. In the remaining thirteen afferents there were no detectable changes in excitability.Bladder distension in the absence of micturition failed to change the excitability of any SPud afferents tested. 3. Almost all SPud afferents were subject to PAD upon stimulation of cutaneous nerves.Superficial perineal, long saphenous, caudal cutaneous sural and the predominantly cutaneous posterior tibial nerves were particularly effective in evoking PAD. While group I strength stimulation of hindlimb muscle-nerves produced PAD of some SPud fibres, group II stimulation often increased the magnitude or incidence of PAD. The patterns and magnitude of PAD observed in SPeri afferents were similar to those observed in SPud afferents.4. Since some SPud afferents were subject to PAD during micturition, PAD is prpbably one mechanism responsible for suppression of sphincter reflexes during niicturition.Additional roles of PAD of perineal afferents evoked by activation of hindlimb cutaneous and muscle afferents are discussed.

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Depolarization of group II muscle afferents by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

Cited by 49 publications

References 43 publications

Gating of transmission to motoneurones by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

Gating of transmission to motoneurones by stimuli applied in the locus coeruleus and raphe nuclei of the cat.

Pharmacological characterization of serotonin receptor subtypes modulating primary afferent input to deep dorsal horn neurons in the neonatal rat

Primary afferent depolarization of cat pudendal afferents during micturition and segmental afferent stimulation.

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