Ishimoto T, Omori N, Mutoh F, Chiba S
Department of Psychiatry and Neurology, Asahikawa Medical College, Midorigaoka higashi 2-1-1-1, 078-8510, Asahikawa, Japan.
Brain Res. 2000 Oct 27;881(2):152-8. doi: 10.1016/s0006-8993(00)02830-4.
Effects of microinjections of a single 2 or 10 nmol dose of N-methyl-D-aspartate (NMDA) into the unilateral mesencephalic reticular formation (MRF) on behavior and electroencephalogram were examined in rats (n=18) during a 15 min period (Exp. 1), and subsequent effects of sound stimulation with key jingling applied at 15, 30, and 45 min after the injections were observed (Exp. 2). The microinjections of 2 nmol dose of NMDA (n=10) induced hyperactivity (9 of 10 rats) and running/circling (8 of 10 rats) in Exp. 1, and hyperactivity (3 of 10 rats) in Exp. 2. Moreover, the microinjections of 10 nmol dose of NMDA (n=8) induced not only hyperactivity (8 of 8 rats) and running/circling (7 of 8 rats) but also generalized tonic-clonic seizures (GTCS) (5 of 8 rats) in Exp. 1; these seizure patterns were also elicited by sound stimulation in Exp. 2. The seizure patterns were accompanied by electroencephalographic seizure discharges in the MRF and the motor cortex. In contrast, the control group rats (n=10) which received a single dose of saline microinjection into the unilateral MRF showed no behavioral or electroencephalographic changes in both Exp. 1 and 2. These findings suggest that the MRF has an important role in the development of GTCS, which follows hyperactivity and running/circling, and that potentiation of excitatory neurotransmission in the MRF participates in the development of audiogenic seizures as well as GTCS.
在15分钟内，对18只大鼠（实验1）进行了研究，向其单侧中脑网状结构（MRF）微量注射单剂量2或10纳摩尔的N-甲基-D-天冬氨酸（NMDA），观察其对行为和脑电图的影响；随后，在注射后15、30和45分钟施加钥匙叮当声的声音刺激，观察后续影响（实验2）。在实验1中，2纳摩尔剂量的NMDA微量注射（n = 10）使10只大鼠中的9只出现多动，10只大鼠中的8只出现奔跑/转圈；在实验2中，使10只大鼠中的3只出现多动。此外，在实验1中，10纳摩尔剂量的NMDA微量注射（n = 8）不仅使8只大鼠中的8只出现多动、8只大鼠中的7只出现奔跑/转圈，还使8只大鼠中的5只出现全身性强直阵挛性癫痫发作（GTCS）；在实验2中，这些癫痫发作模式也由声音刺激诱发。癫痫发作模式伴有MRF和运动皮层的脑电图癫痫放电。相比之下，在实验1和实验2中，单侧MRF接受单剂量生理盐水微量注射的对照组大鼠（n = 10）未出现行为或脑电图变化。这些发现表明，MRF在GTCS的发生中起重要作用（GTCS继发于多动和奔跑/转圈），并且MRF中兴奋性神经传递的增强参与了听源性癫痫发作以及GTCS的发生。
