Abstract
The present study examined developmental patterns of antinociception mediated by the spinal 5-HT3 receptor system in the neonatal rat. Intrathecally administered 2-methylserotonin (25-100 micrograms) first produced antinociception against formalin-induced acute inflammatory pain at 10 days postnatally, with effect only at the peak dose (100 micrograms). Intrathecal 2-methylserotonin produced dose-dependent antinociception at 14 and 28 days of age that was attenuated by i.t. pretreatment with the 5-HT3 receptor antagonist MDL-72222 (10 micrograms).
MeSH terms
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Animals
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Animals, Newborn
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Dose-Response Relationship, Drug
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Formaldehyde
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Inflammation / chemically induced
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Injections, Spinal
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Male
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Nociceptors / drug effects*
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Pain Measurement
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Rats
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Rats, Sprague-Dawley
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Receptors, Serotonin / drug effects
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Receptors, Serotonin / physiology
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Serotonin / analogs & derivatives*
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Serotonin / pharmacology
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Serotonin Antagonists / pharmacology
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Spinal Cord / chemistry
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Spinal Cord / drug effects
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Spinal Cord / growth & development*
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Tropanes / pharmacology
Substances
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Receptors, Serotonin
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Serotonin Antagonists
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Tropanes
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Formaldehyde
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Serotonin
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2-methyl-5-HT
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bemesetron