Role of serotonin1A receptors on the modulation of rat spinal mono-synaptic reflexes in vitro

Hedo, G.; Ajubita, Mar; López-García, J.A.

doi:10.1016/s0304-3940(02)01064-9

Cited by 9 publications

(6 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consistent with these findings, 8-OH-DPAT has been shown ineffective at modulating nociceptive spinal reflexes [49]. In contrast, intra-peritoneal administration of the potent 5-HT 1A agonist F 13640 produces a selective reduction of responses to nociceptive pinch and to short term forms of synaptic plasticity in dorsal horn neurones and ventral motor units [50].…”

Section: Effects Mediated By 5-ht 1 Receptorsmentioning

confidence: 63%

“…An inhibitory role for 5-HT 1A receptors in this pathway has been proposed because low concentrations of 8-OH-DPAT produce a strong blockade of the monosynaptic reflex recorded from motoneuronal populations. This effect is fully reversed by (+)WAY 100135 applied at low concentrations as well [49]. The 5-HT 1A receptor could mediate a reduction of synaptic release from muscle afferents by blocking a calcium conductance as demonstrated for thinner afferents [34].…”

Section: Effects Mediated By 5-ht 1 Receptorsmentioning

confidence: 99%

“…It is interesting to note that 5-CT and 5-HT depress this reflex as well but in these cases (+)WAY 100135 is only a partially effective antagonist. In addition to the 5-HT 1A receptor, other 5-HT 1 receptor subtypes like the 5-HT 1B and 5-HT 1D have been implicated in the control of muscle reflex pathways [43][44][45][46][47][48][49][50][51][52][53][54][55]. Depression of transmission through this pathway can cause deficits in motor control and, therefore, behavioural tests using compounds active at these receptors should include a rigorous control of motor function.…”

Section: Effects Mediated By 5-ht 1 Receptorsmentioning

confidence: 99%

See 2 more Smart Citations

Serotonergic Modulation of Spinal Sensory Circuits

López-García

2006

CTMC

View full text Add to dashboard Cite

The role of serotonin (5-HT) as a mediator of the endogenous pain control system has been investigated over the last 30 years. Here we review a subset of studies that used electrophysiological techniques to study the mechanisms of action as well as the receptors mediating the spinal effects of serotonin. The works herein discussed employed in vivo or in vitro preparations of control or hyperalgesic animals. According to these reports, 5-HT triggers depressant effects on synaptic transmission limiting the release of neurotransmitters from afferent terminals or the responsiveness of NMDA receptors located in dorsal horn neurones. These mechanisms are most likely mediated by 5-HT1 receptors. In contrast, 5-HT2 receptors seem to mediate excitatory effects such as depolarisation, increased excitability, and neurotransmitter release. The role of 5-HT3 receptors is less clear as they could mediate excitatory or inhibitory effects, depending on variables such as concentration of 5-HT or the state (sensitised/unsensitised) of the spinal cord. The consequences of these spinal effects of serotonin are discussed in the context of pain and analgesia.

show abstract

Section: Effects Mediated By 5-ht 1 Receptorsmentioning

confidence: 63%

Section: Effects Mediated By 5-ht 1 Receptorsmentioning

confidence: 99%

Section: Effects Mediated By 5-ht 1 Receptorsmentioning

confidence: 99%

See 1 more Smart Citation

Serotonergic Modulation of Spinal Sensory Circuits

López-García

2006

CTMC

View full text Add to dashboard Cite

show abstract

“…As well, the effects of 5-HT on the monosynaptic reflex (MSR) are well documented. Similar to the motoneuron, activation of the 5-HT 2 R facilitates the MSR (Miller et al 1996;Machacek et al 2001;Shay et al 2005;Hasegawa and Ono 1996;Gajendiran 2008) and activation of the 5-HT 1A R inhibits the MSR (Hasegawa and Ono 1996;Gajendiran 2007;Nagano et al 1988;Hedo et al 2002).…”

mentioning

confidence: 99%

Removal of supraspinal input reveals a difference in the flexor and extensor monosynaptic reflex response to quipazine independent of motoneuron excitation

Chopek

MacDonell

Power

et al. 2013

Journal of Neurophysiology

View full text Add to dashboard Cite

The purpose of this study was to determine if quipazine, a serotonergic agonist, differentially modulates flexor and extensor motor output. This was achieved by examining the monosynaptic reflex (MSR) of the tibial (extensor) and peroneal (flexor) nerves, by determining the basic and rhythmic properties of extensor and flexor motoneurons, and by recording extracellular Ia field potentials of the tibial and peroneal nerves in the in vivo adult decerebrate rat in both spinal intact and acute spinalized preparations. In the spinal intact preparation, the tibial and peroneal MSR amplitude significantly increased compared with baseline in response to quipazine, with no difference between nerves (P < 0.05). In the spinalized preparation, the MSR was significantly increased in both the tibial and peroneal nerves with the latter increasing more than the former (5.7 vs. 3.6 times; P < 0.05). Intracellular motoneuron experiments demonstrated that rheobase decreased, while input resistance, afterhyperpolarization amplitude, and the firing rate at a given current injection increased in motoneurons following quipazine administration with no differences between extensor and flexor motoneurons. Both the tibial and peroneal nerve extracellular Ia field potentials increased with the peroneal demonstrating a significantly greater increase (7 vs. 38%; P < 0.05) following quipazine. It is concluded that in the spinal intact preparation quipazine does not have a differential effect on flexor or extensor motor output. However, in the acute spinalized preparation, quipazine preferentially affects the flexor MSR compared with the extensor MSR, likely due to the removal of a descending tonic inhibition on flexor Ia afferents.

show abstract

“…Such a motor-inhibitory effect could take place at peripheral sites, directly in the muscle, or at a spinal level, modulating the activity of the efferent motor pathways. Several reports implicate spinal 5-HT 1A receptors in the modulation of spinal motor reflexes, resulting in both the inhibition of withdrawal monosynaptic spinal reflexes and the enhancement of motor activity (Clarke and Ward, 2000;Hedo et al, 2002;Zimmer and Goshgarian, 2006;Gajendiran, 2008). Therefore, it is possible that the inhibitory effects exerted by AZD7371 and by WAY-100635 on the VMRs to CRD are due to the 5-TH 1A -dependent modulation of motor reflexes at a spinal level, without interference with the afferent processing of pain signals.…”

Section: Discussionmentioning

confidence: 99%

The Selective 5-Hydroxytryptamine 1A Antagonist, AZD7371 [3(R)-(N,N-Dicyclobutylamino)-8-fluoro-3,4-dihydro-2H-1-benzopyran-5-carboxamide (R,R)-tartrate Monohydrate] (Robalzotan Tartrate Monohydrate), Inhibits Visceral Pain-Related Visceromotor, but Not Autonomic Cardiovascular, Responses to Colorectal Distension in Rats

Lindström¹,

Ravnefjord²,

Brusberg³

et al. 2009

J Pharmacol Exp Ther

View full text Add to dashboard Cite

, and 14 mol/kg, respectively). In telemetrized rats, oral AZD7371 inhibited visceromotor responses to CRD without affecting the concomitant hypertensive and tachycardic responses. Intracerebroventricular AZD7371 did not affect visceromotor responses, whereas it inhibited micturition. None of the doses tested induced visible gross side effects. AZD7371, likely acting at a spinal site, inhibited the visceromotor but not the cardiovascular responses to visceral pain in the CRD model in rats. Although agents effective on multiple pain-related readouts in the CRD model (e.g., pregabalin or clonidine) alleviate IBS symptoms, AZD7371, which is effective on only one pain-related pseudoaffective readout, does not. Data from preclinical CRD models of visceral pain need to be interpreted cautiously as it relates to their clinical translational value.

show abstract

Role of serotonin1A receptors on the modulation of rat spinal mono-synaptic reflexes in vitro

Cited by 9 publications

References 16 publications

Serotonergic Modulation of Spinal Sensory Circuits

Serotonergic Modulation of Spinal Sensory Circuits

Removal of supraspinal input reveals a difference in the flexor and extensor monosynaptic reflex response to quipazine independent of motoneuron excitation

Contact Info

Product

Resources

About