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Serotonin differentially modulates the intrinsic properties of spinal motoneurons from the adult turtle
Author(s) -
Perrier JeanFrançois,
Cotel Florence
Publication year - 2008
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2007.145706
Subject(s) - serotonergic , facilitation , inhibitory postsynaptic potential , plateau (mathematics) , neuroscience , turtle (robot) , 5 ht receptor , serotonin , spinal cord , receptor , chemistry , biology , biochemistry , mathematical analysis , mathematics , fishery
This report considers serotonergic (5‐HT) effects on spinal motoneurons, reviewing previous data and presenting a new study showing distinct effects of two 5‐HT receptor subtypes. We previously investigated the effects of 5‐HT on motoneurons in a slice preparation from the spinal cord of the adult turtle. In agreement with previous studies, we had found that 5‐HT applied to the extracellular medium promoted a voltage sensitive plateau potential. However, we also reported that this effect was only observed in half of the motoneurons; 5‐HT inhibited the firing of the other half of the motoneurons recorded from. To investigate the reasons for this, we applied 5‐HT focally by means of the microiontophoresis technique. Facilitation of plateau potentials was observed when 5‐HT was released at sites throughout the somatodendritic region. However, motoneurons were inhibited by 5‐HT when selectively applied in the perisomatic region. These two effects could be induced in the same motoneuron. With pharmacological tools, we demonstrate here that the facilitation of plateau potentials is mediated by 5‐HT 2 receptors and the inhibitory effect is due to the activation of 5‐HT 1A/7 receptors.