CHOLINERGIC MECHANISMS IN THE RETICULAR CONTROL OF TRANSMISSION IN THE CAT LATERAL GENICULATE-NUCLEUS
CHOLINERGIC MECHANISMS IN THE RETICULAR CONTROL OF TRANSMISSION IN THE CAT LATERAL GENICULATE-NUCLEUS
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DOI：
10.1152/jn.1988.59.6.1690
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发表时间：
1988-06-01
影响因子：
2.5
通讯作者：
SINGER, W
中科院分区：
文献类型：
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作者：
FRANCESCONI, W;MULLER, CM;SINGER, W
1.我们检验了上行网状唤起系统通过胆碱能机制影响丘脑传递的假设。用N_2O和戊巴比妥或N_2O和氟烷麻醉猫的背外侧膝状体核（LGNd）和膝状体周围核（PGN）神经元，获得细胞外和细胞内记录。我们比较了电刺激中脑网状结构（MRF）和离子导入应用乙酰胆碱（ACh）对单个神经元的自发和诱发活动的影响，并测试了这些影响是否可以通过离子导入管理的毒蕈碱受体阻滞剂东莨菪碱拮抗。此外，还检查了离子导入应用谷氨酸（GLU）、N-甲基-D-天冬氨酸和荷包牡丹碱的影响。2. ACh应用和MRF刺激在LGNd中继细胞中的突出效果是静息放电的增强，对光的兴奋性反应的促进，诱发抑制发作的幅度和持续时间的减少，以及抑制后反弹爆发的阻断。后者的效果类似于荷包牡丹碱诱导的效果。在巴比妥麻醉下，当视网膜的兴奋性输入被阻断时，ACh应用或MRF刺激都不会引起放电。在20个受试的中继细胞中，应用毒蕈碱拮抗剂东莨菪碱可完全阻断ACh离子电泳的作用，并在10个细胞中完全拮抗MRF刺激的作用。在其余的细胞中，东莨菪碱降低了MRF刺激的作用。3.增加麻醉深度减少或消除ACh应用和MRF刺激对细胞静息活动的影响，但不干扰诱发反应的易化。4.兴奋性氨基酸GLU和NMDA的作用不同于MRF刺激和ACh应用，因为前者总是增强自发和诱发放电，但既不缩短诱发抑制相，也不取消抑制后反弹爆发。5.在单个神经元中，MRF刺激和ACh应用的有效性之间存在高度相关性。平均而言，诱发反应的促进作用在X-细胞中比在Y-细胞中更明显，并且在X-细胞中比在Y-细胞中响应静息活性增加的细胞的分数在X-细胞中比在Y-细胞中高得多。（400字处截断摘要）
1. We examined the hypothesis that the ascending reticular arousal system influences thalamic transmission through a cholinergic mechanism. Extra- and intracellular recordings were obtained from neurons of the dorsal lateral geniculate nucleus (LGNd) and the perigeniculate nucleus (PGN) of cats anesthetized either with N2O and pentobarbital or with N2O and halothane. We compared the effects that electrical stimulation of the mesencephalic reticular formation (MRF) and ionophoretically applied acetylcholine (ACh) have on spontaneous and evoked activity of individual neurons and tested whether these effects could be antagonized by ionophoretic administration of the muscarinic receptor blocker scopolamine. The effects of ionophoretically applied glutamate (GLU), N-methyl-D-aspartate, and bicuculline were examined in addition. 2. The prominent effects in LGNd relay cells of both ACh application and of MRF stimulation were an enhancement of the resting discharge, a facilitation of the excitatory responses to light, a reduction of the amplitude and duration of evoked inhibitory episodes, and a blockade of postinhibitory rebound burst. These latter effects resembled those induced with bicuculline. Under barbiturate anesthesia neither ACh application nor MRF stimulation elicited discharges when the excitatory input from the retina was blocked. Ionophoretic application of hte muscarinic antagonist scopolamine abolished the effects of ACh ionophoresis in all relay cells tested (n = 20), and in 10 cells it also antagonized completely the effects of MRF stimulation. In the remaining cells scopolamine reduced the effects of MRF stimulation. 3. Increasing the depth of anesthesia reduced or abolished the effects of ACh application and MRF stimulation on the cells' resting activity but did not interfere with the facilitation of evoked responses. 4. The effects of the excitatory amino acids GLU and NMDA differed from those of MRF stimulation and ACh application, since the former always enhanced both spontaneous and evoked discharges but neither shortened phases of evoked inhibition nor abolished postinhibitory rebound bursts. 5. There was a high correlation between the effectiveness of MRF stimulation and ACh application in individual neurons. On the average, the facilitation of evoked responses was more pronounced in X- than in Y-cells, and the fraction of cells responding with an increase of resting activity to both procedures was considerably higher among X- than among Y-cells.(ABSTRACT TRUNCATED AT 400 WORDS)