TY - JOUR
T1 - Serotonin differentially modulates the intrinsic properties of spinal motoneurons from the adult turtle.
AU - Perrier, Jean-Francois Marie
AU - Cotel, Florence
N1 - Keywords: Action Potentials; Animals; Motor Neurons; Muscle Contraction; Muscle, Skeletal; Receptor, Serotonin, 5-HT1A; Receptors, Serotonin; Serotonin; Spinal Cord; Synapses; Turtles
PY - 2007
Y1 - 2007
N2 - 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.
AB - 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.
U2 - 10.1113/jphysiol.2007.145706
DO - 10.1113/jphysiol.2007.145706
M3 - Journal article
C2 - 18096602
SN - 0022-3751
VL - 586
SP - 1233
EP - 1238
JO - Journal of Physiology
JF - Journal of Physiology
IS - 5
ER -