Anodal Transcranial Direct-Current Stimulation Over the Right Dorsolateral Prefrontal Cortex Influences Emotional Face Perception / 神经科学通报·英文版

The dorsolateral prefrontal cortex (DLPFC) is considered to play a crucial role in many high-level functions, such as cognitive control and emotional regulation. Many studies have reported that the DLPFC can be activated during the processing of emotional information in tasks requiring working memory. However, it is still not clear whether modulating the activity of the DLPFC influences emotional perception in a detection task. In the present study, using transcranial direct-current stimulation (tDCS), we investigated (1) whether modulating the right DLPFC influences emotional face processing in a detection task, and (2) whether the DLPFC plays equal roles in processing positive and negative emotional faces. The results showed that anodal tDCS over the right DLPFC specifically facilitated the perception of positive faces, but did not influence the processing of negative faces. In addition, anodal tDCS over the right primary visual cortex enhanced performance in the detection task regardless of emotional valence. Our findings suggest, for the first time, that modulating the right DLPFC influences emotional face perception, especially faces showing positive emotion.

Superior colliculus-pulvinar-amygdala subcortical visual pathway and its biological significance / 生理学报

Superior colliculus-pulvinar-amygdala pathway is one of the subcortical visual pathways in mammalian brain. Some recent studies suggest that this pathway is involved in processing emotion-related visual information. This review discusses the possibility that this pathway is more related to visual alert rather than simply the early visual information processing. The biological significance of this pathway is also discussed. Instead of detecting "where" or "what" the visual target is, the task of this early visual stage is to send out a warning signal, i.e., "something appears", so that the brain can be set up in a state of alert, which is important for the survival of animals. Thus, in the early visual information process, detection of new object "emerging" or "disappearing" takes priority over the acquisition of its feature information of "texture" and "shape", etc. The subcortical pathway may provide the neural basis of early visual warning in topological perception, a biological significance critical for animal survival.

Dynamics of hippocampal sensory gating during the chronic morphine administration, withdrawal and re-exposure to morphine in rats / 生理学报

Drug addiction is considered as a chronic, recurrent brain disease characterized by relapse. Repeated exposure to certain drugs, such as morphine, can produce deleterious sequelae, such as drug dependence, tolerance and compulsive drug seeking. In the present study, we investigated the dependence and psychological craving for morphine in rats using the conditioned place preference (CPP) paradigm. On the other hand, to study the effect of morphine on hippocampal sensory gating (N40), double click auditory-evoked potential was recorded during the chronic morphine administration, withdrawal and re-exposure to morphine in rats. The rats in morphine group received a course of morphine (10 mg/kg, i.p.) injection for 12 d, followed by 12 d of withdrawal, 1 d of re-exposure to morphine (2.5 mg/kg, i.p.) and 2 d of the second withdrawal. The rats in the control group were treated in the same way except that saline was applied instead of morphine. CPP test demonstrated that the method of drug administration in the present study induced dependence and psychological craving for morphine in rats. The results in the double click auditory-evoked potential experiment showed that during the chronic morphine administration, hippocampal N40 gating was damaged. In the initial 2 d of the first withdrawal hippocampal N40 gating in morphine group was reduced compared with that in the control group and it was significantly greater on the 3rd day, and then recovered gradually to the normal level from day 4 to day 12. After re-exposure to morphine, hippocampal N40 gating in morphine group was significantly reduced compared with that in the control group, and it remained at a lower level during the following 2 d, suggesting that hippocampal N40 gating in rats was more sensitive to morphine during re-exposure. Our results suggest that long-term repeated morphine administration and re-exposure to morphine disrupt hippocampal N40 gating, and that the effect of morphine addiction on the brain is possibly long-term.

Effects of morphine on the development of chick embryos / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effect of morphine on fetal movement, heart rate, hatch weight, hatch days and hatch rate.</p><p><b>METHODS</b>Morphine was injected into airspace of eggs and fetal movement, heart rate, hatch weight, hatch days and hatch rates were recorded.</p><p><b>RESULTS</b>Hatch days were shorter, hatch rates were lower and some chicks became motor disorder for morphine. Chicks with morphine exposure 20 mg/kg from E 12 to E 16 had highest hatch rate and lowest disable rate. Morphine reduced fetal movement, increased heart rate (P < 0.05).</p><p><b>CONCLUSION</b>The development of chick embryo is impaired by morphine exposure and the magnitude of these effects depends on the drug dose and the length of time that the developing organism is exposed to morphine.</p>

Methods for single unit recording in behavioring morphine craving rat / 生理学报

In this paper, one method was introduced, which was a combination of the cue-related morphine addiction model and a technique for obtaining chronic extracellular recordings of single unit in freely moving rats. With the combination and improvement of this technique, we have successfully applied this new method to study the neuronal activity of the hippocampus CA1 region in morphine withdrawal rats. In all, we found some more accurate and objective cellular characteristics of hippocampal neurons, and considered these characteristics as one of electrophysiological indexes of morphine addiction rats.