Noxious visceral inputs enhance cutaneous tactile response in rat thalamus.
The current study investigates whether visceral nociceptive inputs affect tactile processing in the thalamic ventroposterior lateral nucleus in anesthetized rats by means of extracellular single unit recordings. Twenty out of the 44 neurons had their response to tactile stimulation increased by preceding nociceptive colorectal distension (CRD), and this influence appear more potent than the opposite effect, tactile on CRD response. There was a dynamic change of tactile response along with CRD response and the background activities as a function of repeated colorectal stimulation. The abnormal neuronal discharge in response to tactile stimulation in the condition of visceral nociception could contribute to the development of referred pain and allodynia.
Zhang
Hong-Qi
HQ
School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong. hqzhang@hkbu.edu.hk
Rong
Pei-Jing
PJ
Zhang
Shi-Ping
SP
Al-Chaer
Elie D
ED
Willis
William D
WD
D000200:Action Potentials; D000818:Animals; D002404:Catheterization; D003106:Colon / Q000294:innervation / Q000503:physiopathology*; D004594:Electrophysiology / Q000379:methods; D005073:Evoked Potentials, Somatosensory; D009433:Neural Inhibition; D009474:Neurons; D009619:Nociceptors / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology*; D010812:Physical Stimulation; D011312:Pressure; D051381:Rats; D012007:Rectum / Q000294:innervation / Q000503:physiopathology*; D011984:Sensory Receptor Cells; D012867:Skin / Q000503:physiopathology; D013788:Thalamus / Q000503:physiopathology; D014110:Touch; D020651:Ventral Thalamic Nuclei / Q000503:physiopathology*; D014732:Vibration; D014781:Viscera / Q000294:innervation / Q000503:physiopathology; D017833:Visceral Afferents / Q000503:physiopathology*