Effects of a single injection of methamphetamine on central dopaminergic systems in rats with hippocampal lesions

✍ Scribed by Yoshie Kitao; Toshiya Inada; Yohko Maeda; Hajime Sasaki; Masaomi Iyo

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 412 KB
• Volume: 19
• Category: Article
• ISSN: 0893-6609
• DOI: 10.1002/(sici)1520-6769(199607)19:1<1::aid-nrc157>3.0.co;2-g

✦ Synopsis

Effects of a single injection of methamphetamine (2 m a g , i.p.) on central dopaminergic systems were investigated among rats with bilateral hippocampal lesions by ibotenic acid (10-11 weeks, n=6), age-matched sham-lesioned rats (10-11 weeks, n=6), and aged sham-lesioned rats (40-42 weeks, n=7), using an in vivo microdialysis technique coupled with an animal movement analysis system. Striatal dopamine levels, measured 2 weeks after lesioning, were significantly increased aftcr the singlc injection of methamphetamine in the ibotenic acid-lesioned and the sham-lesioned rats, and a significant dccrease was observed in the levels of homovanillic acid (HVA) and 3,4-dihydroxy phenylacetic acid (DOPAC) in all three groups. Response to a single injection of methamphetamine tcndcd to bc slower in aged than in non-aged sham-lesioned rats. Counts of vertical movements tended to be higher (p<0.1) at 5 min after thc methamphetamine injection in the ibotenic acid-lesioned than in the shamlesioned rats, and tended to bc lower (p<O.l) at 60 min after the injection in the aged than in the non-aged sham-lesioned rats. The present results suggest that, although the effects of a decrease in cholinergic function on striatal dopaminergic systems measured as methamphetamine-induced bchavioral and neurochemical alterations are subtle, these effects derived from the normal aging process could be different from those induced by hippocampal lesions of ibotenic acid.