ISSN : 1226-9654
This study is concerned with the question whether the prelimbic area and anterior cingulater cortes of the rat is important subtrates in the spatial localization task and visually-cued task with Morris water maze. In the spatial localization tasks, with the invisible platform, rats with either prelimbic area or anterior cingulate cortex lesions were subjected to spatial reference memory task, tranfer test and then spatial working memory task. Animals with prelimbic area lesion learned and remembered the spatial task equally as well as their controls. However Animals with anterior cingulater cortex lesion were initially slower in localizing the invisible platform than controls in the spatial reference and the spatial working memory tasks but the impairments were transient. In the visually-cued task with visible platform, animals with prelimbic area lesion showed a transient impairment but animals with cingulate cortex lesion no impairment. Their results were interpreted as showing that prelimbic area may be involved in the attentional control and anterior cingulate cortex in the learning of rules and response reorganization in a new and challenging situation.
Morris water maze is one of the most extensively used tasks to investigate spatial learning and memory in rodents. In the probe test of the task, most researchers have measured the time spent navigating in the previous "target quadrant" where the platform had been during training. We compared the target quadrant data with the time swum in a narrow "target area" that was defined as a diameter-40 cm circle round the center of the platform. The target quadrant data were liable to overestimate the memory of poor learners, in which the basal nucleus of Meynert, a key structure of chlonergic system, was destroyed. It was proved by a bivariate regression analysis that the target area data are more valid than the target quadrant data. The results suggest that the target area data should be gathered as a alternative memory index together with the target quadrant data in future studies using Morris water maze.
Neuropathic pain which is a chronic pain state can be produced by injury of peripheral nerves or tissues. Traditionally, opioids have been used to alleviate pain but have not been effective in treating neuropathic pain. A series of studies were conducted in order to elucidate whether adrenergic agents can inhibit neuropathic pain and are related to opioid system, and how adrenergic system and opioid system interact. Mechanical allodynia, cold allodynia, and spontaneous pain were developed gradually after injury to the tibial and sural nerves, peaking at 14 days postoperatively. Intraperitoneally injected clonidine, an α2-adrenergic agonist, inhibited mechanical allodynia and cold allodynia. Pretreated naloxone, an opioid antagonist, reversed the effects of clonidine. Yohimbine, an α2-adrenergic antagonist, rather tended to increase neuropathic pain. Pretreated naloxone tended to reverse the effects of yohimbine. The results suggest that alpha-2 adrenergic receptors interact with opioid receptors in the modulation of neuropathic pain.
The present study examined whether conditioned fear to a CS would decrease after extensive active avoidance training. Suppression ratios calculated from the change of general activity induced by CS presentation in an activity box were used as a measure of conditioned fear. In experiment 1, rats received classical conditioning by pairing a light CS with footshock US 1, 3, 9, or 27 times and were tested for conditioned fear. The more conditioning trials the animals received, the higher the conditioned fear to the CS. In experiment 2, animals received 15 active avoidance training trials on day 1 and assigned to 3 groups based on their performance. On day 2, they were trained to a criterion of 3, 9, or 27 consecutive avoidance responses, and one day later, tested for conditioned fear to the CS. All three groups showed similar degree of conditioned fear. This result indicating that extensive active avoidance training does not decrease conditioned fear to the CS is not consistent with the results of most of the previous studies, and possible reasons for this discrepancy is discussed.
Substantial evidence suggests that behavioral and reinforcing effects of cocaine can be mediated by the mesolimbic dopaminergic system. Many studies have shown that Coptidis Rbizoma has a suppressive effect on the central nervous system (CNS) can affect the neurotransmitter systems in the CNS. In order to investigate whether Coptidis Rbizoma has an influence on cocaine-induced reinforcement and behavioral sensitization, we examined the effect of Coptidis Rbizoma on repeated cocaine-induced locomotor activity and c-Fos expression in the nucleus accumbens and the striatum utilizing Fos-like immunohistochemistry method. Male SD rats received Coptidis Rbizoma (200mg/kg, p.o.) 30 min before injections of cocaine (15mg/kg, i.p.) for 10 days. Rats were followed withdrawal for 3 days and one challenge for 1 day. Systemic challenge with cocaine produced a much larger increase in locomotor activity and expression of c-Fos in the nucleus accumbens and the striatum. Pretreatment with Coptidis Rbizoma decreased in cocaine-induced locomotor activity and c-Fos expression. These results demonstrated that reduction in locomotor activity by Coptidis Rbizoma may be mediated by reduction of dopamine release and of postsynaptic neuronal activity in the nucleus accumbens. Our results suggest that Coptidis Rbizoma may have therapeutic effect on cocaine addiction.
This study assessed whether frontal brain asymmetry(FBA) can predict affective style. Resting electroencephalographic(EEG) activity was recorded from male and female adults participants during both 5 eyes-open and 5 eyes-closed 60-s baselines on 1 measurement occasion. Mean alpha power asymmetry was extracted in midfrontal and lateral-frontal sites. For the midfrontal site, but not the lateral-frontal site, there was a significant relationship between relative left anterior activation and increased positive affect and relative right anterior activation was significantly related to negative affect. Contrary to predictions, FBA was unrelated to anxiety in two sites. This results suggest that midfrontal FBA may be a state-independent measure of affective style. Theoretical and methodological implications of these findings are discussed.
The visual glide slope indicator is a system of lights so arranged to provide visual descent guidance information during the approach to a runway. Now the precision approach path indicator(PAPI) is used in most airports as a visual glide slope indicator. The PAPI has little compatibility with the judgement of the above and the below due to horizontal arrangement. Therefore, it is difficult to judge intuitively the above and the below with the PAPI. To improve this weakness, we suggest a vertical-precision approach path indicator (V-PAPI), and try to evaluate if it is more efficient than the PAPI. In experiment 1, the stimuli of PAPI and V-PAPI were repeatedly presented to ordinary subjects, who didn`t have any experience of the PAPI. The subject responded with a vertical arranged button press to the stimuli, and event-related potentials(ERP) recordings obtained from Fz, Cz, and Pz. As a result of behaviroral response, there was no significant difference at a response time of button press between the PAPI and the V-PAPI, but response error of the V-PAPI were less than that of the PAPI. In the ERP analyses, there was no difference at the latency of P300 between the PAPI and the V-PAPI, but V-PAPI P300 amplitude was larger than the PAPI P300 over the all electrode sites. In experiment 2, 6 pilots employed as a subject and the experiment method was identical with that of the experiment 1. No differences found between two indicators at the latency and error of button press and the P300 latency, but V-PAPI P300 amplitude was larger than the PAPI, though the pilots were accustomed to the PAPI. The results suggest that the V-PAPI is more efficient than the PAPI in judgement of the glide slope due to a vertical arrangement which is correspondent with concept of the above and the below.
Most of the researches conducted in search of a coronary prone personality has focused on the TABP(Type A behavior pattern), a collection of behaviors that seems predictive of CHD(coronary heart disease). The two primary methods of assessing TABP are the SI(Structured Interview) and JAS(Jenkins Activity Survey). JAS is more convinient but has a weaker predictive value than SI. The hostility is the one that JAS does not measure but SI measures. The higher predictive value of SI may be ascribed to the measurement of the hostility. The hypothesis was that type A and hostility might be additive effect to predict CHD. In this study, seventy two persons were divided by 4 groups, type A with high hostility(HA), type A with low hostility(LA), type B with high hostility(HB), and type B with low hostility(LB)). It was expected that the type A and the hostility had additive effect on the HA group, but the additive effect was appeared only in anxiety of the HA group. Instead, the effect of the hostility was significant on depression, anxiety, and FBV(finger biood volume). The high hostile(HH) group had significantly higher scores of depression and anxiety than the low hostile(LH) group. The baseline HR(heart rate) was higher and the baseline FBV of the HH group was lower than the LH group in the rest period. It can be interpreted that the HH group is watchful even in the rest period. But in the task period, the HH group had shown less decrease of FBV than LH. Much decrease of LH group can be interpreted as energy mobilization to cope well, too. The HH group had higher depression and anxiety scores, that is, the group is psychologically less healthier than the LH group. The FBV of the HH group showed that their arousal level was higher in the rest period but lower in the task period than LH group. These facts suggested that the HH group was not efficient in energy use. It seems that they has the maladaptive strategy of the energy use and their maladaptiveness reflects their unhealthness. This study has found that the hostility does not have interactive effects with type A, the hostility has its own effect on CHD. The results indicate that even if JAS and the hostility are used together, the predictive value of JAS will not be raised.