TY - JOUR
T1 - Central neuronal mechanisms of intestinal electrical stimulation
T2 - Effects on duodenum distention-responsive (DD-R) neurons in the VMH of rats
AU - Zhang, Jing
AU - Zhu, Hongbing
AU - Chen, J. D.Z.
N1 - Funding Information:
This study was partially supported by a grant from Oklahoma Center for the Advancement of Science and Technology (HR07-114) and a grant from NIH (DK063733).
PY - 2009/6/19
Y1 - 2009/6/19
N2 - Intestinal electrical stimulation (IES) has been shown to produce inhibitory effects on gastric contractions, gastric emptying, food intake and body weight in rats and dogs, suggesting a therapeutic potential for obesity. The aims of this study were (1) to test the hypothesis that the neurons in the VMH are involved in the central mechanisms of IES treatment for obesity; (2) to compare the effects of IES at the duodenum and IES at the ileum on neuronal activities of the VMH; (3) to better understand if the neuronal activity modulated by IES was mediated via the vagal pathway. Extracellular potentials of neurons in the VMH were recorded in 18 anesthetized rats. IES at the duodenum or ileum was performed in duodenal-distention responsive (DD-R) neurons with 3 sets of parameters (IES-1 with trains of short-pulses: 4 mA, 2 s-on, 3 s-off, 2 ms, 20 Hz; IES-2 with long-pulses: 6 mA, 20 cpm, 100 ms; IES-3, same as IES-1 but 40 Hz). IES-1 at the duodenum and the ileum activated 70.6% and 73.3% of the DD-R neurons, respectively. Similar percentages of the neurons were activated with IES-3 at the duodenum and the ileum (70.6% vs. 66.7%, P = 0.91), respectively. IES-2 at these locations activated only 25% and 46.2% of the DD-R neurons, respectively (P > 0.05). IES at the duodenum with parameter set, IES-1 or IES-3 was significantly more potent than the parameter set, IES-2 (neuronal activation: 70.6% vs. 25%, P < 0.05). Bilateral vagotomy only partially blocked the effects of IES on the neuronal activity in the VMH, indicating that extra-vagal pathways can mediate these effects. IES with different parameters activates 25-70.6% of the VMH neurons responsive to DD, and IES with trains of short-pulses seems more effective than IES with long-pulses. The vagal pathway and extra-vagal pathways are involved in the modulatory effects of IES on the central neurons in the satiety center.
AB - Intestinal electrical stimulation (IES) has been shown to produce inhibitory effects on gastric contractions, gastric emptying, food intake and body weight in rats and dogs, suggesting a therapeutic potential for obesity. The aims of this study were (1) to test the hypothesis that the neurons in the VMH are involved in the central mechanisms of IES treatment for obesity; (2) to compare the effects of IES at the duodenum and IES at the ileum on neuronal activities of the VMH; (3) to better understand if the neuronal activity modulated by IES was mediated via the vagal pathway. Extracellular potentials of neurons in the VMH were recorded in 18 anesthetized rats. IES at the duodenum or ileum was performed in duodenal-distention responsive (DD-R) neurons with 3 sets of parameters (IES-1 with trains of short-pulses: 4 mA, 2 s-on, 3 s-off, 2 ms, 20 Hz; IES-2 with long-pulses: 6 mA, 20 cpm, 100 ms; IES-3, same as IES-1 but 40 Hz). IES-1 at the duodenum and the ileum activated 70.6% and 73.3% of the DD-R neurons, respectively. Similar percentages of the neurons were activated with IES-3 at the duodenum and the ileum (70.6% vs. 66.7%, P = 0.91), respectively. IES-2 at these locations activated only 25% and 46.2% of the DD-R neurons, respectively (P > 0.05). IES at the duodenum with parameter set, IES-1 or IES-3 was significantly more potent than the parameter set, IES-2 (neuronal activation: 70.6% vs. 25%, P < 0.05). Bilateral vagotomy only partially blocked the effects of IES on the neuronal activity in the VMH, indicating that extra-vagal pathways can mediate these effects. IES with different parameters activates 25-70.6% of the VMH neurons responsive to DD, and IES with trains of short-pulses seems more effective than IES with long-pulses. The vagal pathway and extra-vagal pathways are involved in the modulatory effects of IES on the central neurons in the satiety center.
KW - Central nervous system
KW - Intestinal electric stimulation
KW - Obesity
KW - The ventromedial hypothalamus
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U2 - 10.1016/j.neulet.2009.04.007
DO - 10.1016/j.neulet.2009.04.007
M3 - Article
C2 - 19429155
AN - SCOPUS:67349227410
SN - 0304-3940
VL - 457
SP - 27
EP - 31
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 1
ER -