The Responses of Cardiovascular Neurons After ∆9-tetrahydrocannabinol Administration of the Brainstem in Rats

• Main Authors: Cheng-Che Liu, 劉正哲
• Other Authors: Shwun-De Wang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/24779764268270069593

碩士 === 國防醫學院 === 生物及解剖學研究所 === 93 === ∆9-tetrahydrocannabinol (THC) is the primary psychoactive constituent of plant cannabis, which cause euphoria, stimulate appetite, change in locomotion, impairment of cognition, analgesia and increase/or decrease body weight by activation of specific G-protein couple receptor. Also, it has long been recognized that THC acts on the brainstem to regulate cardiovascular function. However, it still lacks of morphological evidences to show cellular responses of cardiovascular neurons in the brainstem after THC treatment. In this study, body weight measurement and immunohistochemistry of c-fos, dopamine-beta- hydroxylase (DBH) and neuronal nitric oxide synthase (nNOS) will be used for examining the cells in response to THC in rat brainstem. The current data demonstrated that the body weight was significantly attenuated in chronically THC-treated animals. The c-fos labeled neurons were significantly increased in numbers in the locus coeruleus (LC), dorsal medulla (DM) and ventrolateral medulla (VLM) of the brainstem in animals acutely THC-treated for 2hrs. In the same groups of animals treated for 6hrs, the c-fos labeled neurons were still obviously increased in number in LC, while those populations of DBH labeled neurons were significantly attenuated in LC and VLM. However, after chronic treatment with THC for 6hrs, the numbers of DBH-positive neurons was significantly attenuated in LC, DM and VLM. In addition, the nNOS-positive neurons in DM and VLM were significantly increased in number after acute THC treatment for 2hrs, but attenuated for 6hrs. The attenuated population of nNOS labeled neurons was also found in LC, DM and VLM after chronic treatment with THC for 6hrs. The current results show that the cellular responses of cardiovascular neurons in cardiovascular areas such as LC, DM and VLM could be modulated after THC treatment. These data may provide morphological evidences in the THC-induced responses of cardiovascular neurons in rat brainstem.