title: Lateral reticular nucleus modulates the cardiosomatic reflex evoked by intrapericardial capsaicin in the rat.
abstract: The current study examined the role of the lateral reticular nucleus (LRN) in modulating the cardiosomatic reflex (CSR) induced by intrapericardial capsaicin in the anesthetized rat. Intrapericardial capsaicin was administered, and the CSR was monitored via electromyogram responses of the dorsal spinotrapezius muscle. Electrical stimulation of the LRN (10, 20 and 30 μA) depressed the CSR induced by intrapericardial capsaicin in an intensity-dependent manner. Microinjection of glutamate (4, 10, 20 and 40 nmol, in 0.2 μL) into the LRN replicated the effects of electrical stimulation. Furthermore, bilateral transections of the dorsolateral funiculus (DLF) decreased the LRN electrical stimulation-induced inhibition of the electromyogram responses. Intrathecal administration of the α2 -adrenergic receptor antagonist yohimbine or the serotonergic receptor antagonist methysergide significantly attenuated the LRN electrical stimulation-induced inhibition of the electromyogram responses. However, intrathecal application of the opioid receptor antagonist naloxone had no effect on the LRN electrical stimulation-induced inhibition. These results suggest that the LRN-DLF-spinal cord pathway is involved in descending inhibition of the CSR, and spinal α2 -adrenergic and serotonergic receptors participate in this descending inhibition.
authors: Department of Physiology and Pathophysiology, Xi'an Jiaotong University College of Medicine, Yanta Road W. 76# Xi'an, Shaanxi 710061, PR China.
authors: Man
authors: M
authors: Han
authors: Xiao-Hua
authors: XH
authors: Liu
authors: Na
authors: N
authors: Sun
authors: Jian-Qing
authors: JQ
authors: Du
authors: Juan-Xia
authors: JX
authors: Zhu
authors: Qiang
authors: Q
authors: Li
authors: Jing-Shi
authors: JS
authors: Tang
mesh_terms: D000818:Animals; D002211:Capsaicin / Q000494:pharmacology*; D004558:Electric Stimulation; D004576:Electromyography; D018698:Glutamic Acid / Q000494:pharmacology; D006321:Heart / Q000294:innervation / Q000502:physiology*; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000294:innervation / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology; D009434:Neural Pathways / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012018:Reflex / Q000187:drug effects / Q000502:physiology*; D018689:Sensory System Agents / Q000494:pharmacology*
chemical_list: D018689:Sensory System Agents; D009270:Naloxone; D018698:Glutamic Acid; D002211:Capsaicin