2004 Fiscal Year Final Research Report Summary
A study on neural plasticity mechanisms of nociceptive transmission induced by peripheral trigeminal nerve injury
Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants |
|Research Institution||Niigata University |
SEO Kenji Niigata University, Graduate School of Medical and Dental Sciences, Associate Professor -> 新潟大学, 大学院・医歯学総合研究科, 助教授 (40242440)
FUJIWARA Naoshi Niigata University, Faculty of Medicine, Professor, 医学部, 教授 (70181419)
MAEDA Takeyasu Niigata University, Graduate School of Medical and Dental Sciences, Professor, 大学院・医歯学総合研究科, 教授 (40183941)
BABA Hiroshi Niigata University, Graduate School of Medical and Dental Sciences, Professor, 大学院・医歯学総合研究科, 教授 (00262436)
|Project Period (FY)
2002 – 2004
|Keywords||trigeminal / Caudalis / membrane excitation / substance p / NK1 receptor / potential development / abnormal sensation / nociception|
1.Optical analysis of membrane potentials in the t trigeminal nociceptive afferent inputs transmission center subnucleus caudalis (Vc) with a high speed recording technique.
(1)It was observed that single stimulation to the trigeminal spinal tract produced excitation transmission with short duration in the Vc, which was mediated by AMPA/Kinate type glutamate receptor.
(2)It was observed that NK 1 and NMDA receptors were involved in the large and long continuing excitation propagation within the Vc caused by electrical stimulation to the trigeminal spinal tract (Tr).
(3)Different developmental changes in the excitation propagation features were observed.
(4)Nociceptive stimuli formalin injection to the cheek produced an enlargement of excitation propagation in the Vc by single stimuli to the Tr.
2.Immunohistochemical study of the spatial distributions of the substance p and NK1 receptor.
(1)Substance P and NK1 receptor were distributed in the superficial layer of the Vc and deep layer in the postnatal week 1.
(2)This distribution pattern changed in the postnatal developmental periods, meaning that neuropeptide relating neural excitation mechanism develops postnatally.
3.Clinical observations of the abnormal sensation caused by peripheral nerve injury.
(1)Spontaneous paresthesia and elicited paresthesia showed different sequential changes after the injury.
(2)Current perception threshold measurements can differentiate damage of Aβ,Aδ, and C fiber. This measurement showed that abnormal sensations related to the dysfunction of the Aβ and C fiber and especially C-fiber damage can relate to the establishment of a part of the abnormal sensations, elicited paresthesia.
Combined with these results, it was suggested that peripheral nerve injury relates to neuropeptide from the afferent terminals in the Vc and this can contribute to establish and maintain some abnormal sensations for a long period after nerve injury.
Research Products (12 results)