Linseman M A, Grupp L A
Psychopharmacology (Berl). 1980;71(1):11-20. doi: 10.1007/BF00433246.
Medial thalamic (MT), and hippocampal (HPC) EEG, and single unit activity, and frontal cortical (CTX) EEG were recorded following IV infusions of 0.625 mg morphine/kg in drug-naive, and following 0.0125 mg naloxone/kg in morphine-dependent paralyzed rats. Particular effort was made to assess the latency of the responses in relation to the appearance of high-voltage bursts in the CTX EEG (which has been shown to correlate well with the behavioral state of the animal) and thereby to assess the possible primacy of the effects. In MT, the predominant effect of morphine on units of naive animals was a decrease in activity; that of naloxone in dependent animals, an increase in activity. Morphine decreased theta activity in the MT EEG, while naloxone precipitated theta activity. In the case of morphine, the majority of unit changes preceded CTX EEG changes; in the case of naloxone, most MT unit and EEG changes either coincided with or followed the changed CTX EEG. In contrast, HPC units were relatively unresponsive to morphine, but the HPC EEG often showed marked spiking following the infusion that generally preceded the appearance of spindles in the CTX. Naloxone caused increases and decreases in HPC unit activity, but these changes as well as those of the HPC EEG (also to theta) generally followed corresponding changes in the CTX EEG. The possibility that both areas might be primary sites of action of morphine, but not naloxone, was discussed.
在未接触过药物的大鼠静脉注射0.625mg吗啡/千克后，以及在吗啡依赖的瘫痪大鼠静脉注射0.0125mg纳洛酮/千克后，记录内侧丘脑（MT）、海马（HPC）的脑电图和单单位活动，以及额叶皮质（CTX）的脑电图。特别努力评估了与CTX脑电图中高压爆发出现相关的反应潜伏期（已证明其与动物的行为状态密切相关），从而评估效应的可能首要性。在MT中，吗啡对未接触过药物动物的单位活动的主要作用是活动减少；纳洛酮对依赖动物的作用是活动增加。吗啡降低了MT脑电图中的θ活动，而纳洛酮引发了θ活动。就吗啡而言，大多数单位变化先于CTX脑电图变化；就纳洛酮而言，大多数MT单位和脑电图变化与CTX脑电图变化同时出现或跟随其后。相比之下，HPC单位对吗啡相对无反应，但HPC脑电图在输注后常显示明显的尖峰，通常先于CTX中纺锤波的出现。纳洛酮导致HPC单位活动增加和减少，但这些变化以及HPC脑电图的变化（也针对θ）通常跟随CTX脑电图的相应变化。讨论了这两个区域可能都是吗啡作用的主要部位，但不是纳洛酮作用部位的可能性。
