Stimulation of a bulbospinal 5-HT pathway in the rat brain produces hyperglycaemia

✍ Scribed by L. R. Shian; M. -T. Lin

• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 571 KB
• Volume: 416
• Category: Article
• ISSN: 0031-6768
• DOI: 10.1007/bf00382696

✦ Synopsis

The glucoregulatory role of spinally projecting serotonin (5-HT) neurones near the ventrolateral surface of the medulla oblongata was investigated by stimulating these nerve cells in normal rats and in rats with selective chemical ablation of 5-HT nerves in the spinal cord. Electrical stimulation of the lateral medulla produced hyperglycaemia in normal rats; the increase in blood glucose was proportional to the intensity and frequency of stimulation. Furthermore, microinjection of kainic acid or L-glutamate at the same sites also produced hyperglycaemia. This stimulation-induced hyperglycaemia was significantly reduced by spinal transection or adrenalectomy. Selective destruction of spinal 5-HT nerves produced by intraspinal injection of 5,7dihydroxytryptamine also reduced the magnitude of the hyperglycaemia response to electrical stimulation of the lateral medulla. This indicates that stimulation of 5-HT nerve cells adjacent to the ventrolateral surface of the medulla oblongata and projecting to the spinal cord increases the adrenal-sympathetic efferent activity and leads to hyperglycaemia in rats.