Descending modulation of visceral nociceptive transmission from the locus coeruleus/subcoeruleus in the rat
| Autor: | Tomio Inoue, Masako Maeda, Bunsho Hayashi, Masayoshi Tsuruoka, Limin Liu, Xiaomin Wang |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Male
medicine.medical_specialty Pentobarbital Colon Spinal neuron Pain Stimulation Inhibitory postsynaptic potential Synaptic Transmission Rats Sprague-Dawley Internal medicine Reaction Time Animals Hypnotics and Sedatives Medicine Evoked Potentials Pain Measurement Neurons business.industry General Neuroscience Rectum Nociceptors Visceral pain Sciatic Nerve Electric Stimulation Rats Electrophysiology Endocrinology Nociception Spinal Cord Anesthesia Locus coeruleus Locus Coeruleus medicine.symptom business medicine.drug |
| Zdroj: | Brain Research Bulletin. 76:616-625 |
| ISSN: | 0361-9230 |
| Popis: | The purpose of the present investigation was to examine whether electrical stimulation in the locus coeruleus/subcoeruleus (LC/SC) could modulate visceral pain evoked by noxious colorectal distention (CRD). Experiments were performed on 40 pentobarbital anesthetized male Sprague-Dawley rats. Extracellular potentials of single L(6)-S(2) spinal neuron were recorded with a carbon filament electrode. CRD (80 mmHg) was produced by inflating a balloon inside the descending colon and rectum. Electrical stimulation of the LC/SC (30, 50 and 70 microA, 100 Hz, 0.1 ms pulses) was delivered either ipsilaterally or contralaterally. Results showed that for 42/62 (68%) short-latency abrupt (SL-A) neurons, all of the short-latency sustained (SL-S) and long-latency (LL) neurons, LC/SC stimulation produced intensity-dependent attenuation of the CRD-evoked discharge. For 10/62 (16%) SL-A neurons, 6/8 (75%) inhibited (INHIB) neurons LC/SC stimulation increased the evoked discharge, for 10/62 (16%) SL-A neurons and 2/8 (25%) INHIB neurons, the evoked discharges were unaffected by the LC/SC stimulation. LC/SC stimulation also had different effects on the spontaneous activities of these neurons. The effects of LC/SC stimulation were the same both ipsilaterally and contralaterally either for the evoked discharges or for spontaneous activities. Following LC/SC lesions, LC/SC stimulation did not inhibit nociceptive responses, whereas inhibitory effects were observed by stimulation of the intact LC/SC contralateral to the recording site. These data suggest that the transmission of visceral pain was under the control of the centrifugal pathways from the LC/SC. |
| Databáze: | OpenAIRE |
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