Different roles of dopamine receptor subtypes in footshock stress-induced enhancement of morphine conditioned place preference

The ability to identify safety and danger is critical to survival. However, not much is known about human somatic body reactions in these contexts. We performed a posturographic study comparing body reactions to the sight of pictures of smiling babies and families (affiliative) versus matched neutral people, and to pictures depicting body envelope violations (mutilation) versus matched neutral people. The participants stood on a force platform and heart rate and displacement of the center of pressure were recorded while the pictures were presented. Pictures of mutilation induced a freezing-like reaction consisting of a medial-lateral (M-L) decrease in the amplitude of sway (immobility) and increase of the mean power frequency (rigidity), associated with bradycardia. Affiliative stimuli also induced an immobility and rigidity behavior but in the anterior-posterior (A-P) axis. This resembles the "immobility-without-fear reaction" proposed to occur when, upon detection of safety cues, mammals including humans are involved in pro-social activities. We conclude that the sight of visual cues of affiliation and danger produce distinct body somatic reactions.     

The antidepressant effect of Cynanchum auriculatum in mice

Context: Antidepressant effects of various plants are generally attributed to their anti-inflammation and antioxidant activities. Cynanchum auriculatum Royle ex Wight (Asclepiadaceae) is a traditional medicinal plant in China and India used for immunological regulation, anti-inflammation, and antioxidant purposes. However knowledge about its antidepressant activity has been poorly investigated.

Objective:To investigate the antidepressant activities of the total glycosides of C. auriculatum (TGC) and its CHCl₃/MeOH (10:1) fractions (TGC-D and TGC-E) in mice.

Materials and methods: TGC, TGC-D and TGC-E (20, 40 and 80 mg/kg) were intragastrically administered to mice twice a day for 5 days. The tail suspension test, forced swimming test, and locomotor activity test in mice were used to evaluate the effect of C. auriculatum. The inhibition of [³H]-serotonin reuptake in rat brain synaptosomes was detected to investigate their mechanism.

Results:TGC, TGC-D and TGC-E (80 mg/kg) decreased the immobility time by 61.7, 64.5, and 61.9% in tail suspension test. TGC (80 mg/kg), TGC-D (80 mg/kg) and TGC-E (20 mg/kg) decreased the immobility time by 32.6, 47.3, and 48.7% in forced swimming test. TGC (80 mg/kg) and TGC-E (20 and 40 mg/kg) decreased the crossing distances by 28.8, 29.5, and 36.2% in locomotor activity test. TGC, TGC-D and TGC-E (10 mg/L) inhibited serotonin reuptake by 7.4, 4.5, and 71.1% in rat brain synaptosomes, and IC₅₀ value of TGC-E was 5.2 mg/L.

Discussion and Conclusion:TGC, TGC-D and TGC-E have potential antidepressant activities. The antidepressive effect of TGC-E maybe attributed partly by the inhibiting effect on serotonin reuptake.     

淫羊藿苷抗抑郁及对皮质酮致PC12细胞损伤的保护作用研究

目的：研究淫羊藿苷的抗抑郁及对皮质酮致PC12细胞损伤的保护作用。方法：采用大／小鼠强迫游泳、小鼠悬尾三种实验模型,将动物随机分为对照组、淫羊藿苷低剂量组、淫羊藿苷高剂量组、阿米替林组,观察药物对大／小鼠强迫游泳不动时间、小鼠悬尾不动时间的影响;并在细胞水平建立皮质酮损伤PC12细胞模型,观察淫羊藿苷的细胞保护作用。结果：在大／小鼠强迫游泳和小鼠悬尾实验中,淫羊藿苷可显著缩短大／小鼠的强迫游泳不动时间和小鼠悬尾不动时间,与对照组相比差异有统计学意义（P〈0．05）;在皮质酮损伤PC12细胞的模型上,淫羊藿苷可显著提高PC12细胞的存活率,拮抗皮质酮诱导的细胞损伤作用。结论：淫羊藿苷具有明显的抗抑郁效果,其抗抑郁作用与神经细胞保护作用有关。     

Computer assisted video analysis of swimming performance in a forced swim test: simultaneous assessment of duration of immobility and swimming style in mice selected for high and low swim-stress induced analgesia

In behavioral pharmacology, two problems are encountered when quantifying animal behavior: 1) reproducibility of the results across laboratories, especially in the case of manual scoring of animal behavior; 2) presence of different behavioral idiosyncrasies, common in genetically different animals, that mask or mimic the effects of the experimental treatments. This study aimed to develop an automated method enabling simultaneous assessment of the duration of immobility in mice and the depth of body submersion during swimming by means of computer assisted video analysis system (EthoVision from Noldus). We tested and compared parameters of immobility based either on the speed of an object (animal) movement or based on the percentage change in the object's area between the consecutive video frames. We also examined the effects of an erosion-dilation filtering procedure on the results obtained with both parameters of immobility. Finally, we proposed an automated method enabling assessment of depth of body submersion that reflects swimming performance. It was found that both parameters of immobility were sensitive to the effect of an antidepressant, desipramine, and that they yielded similar results when applied to mice that are good swimmers. The speed parameter was, however, more sensitive and more reliable because it depended less on random noise of the video image. Also, it was established that applying the erosion-dilation filtering procedure increased the reliability of both parameters of immobility. In case of mice that were poor swimmers, the assessed duration of immobility differed depending on a chosen parameter, thus resulting in the presence or lack of differences between two lines of mice that differed in swimming performance. These results substantiate the need for assessing swimming performance when the duration of immobility in the FST is compared in lines that differ in their swimming “styles”. Testing swimming performance can also be important in the studies investigating the effects of swim stress on other behavioral or physiological parameters because poor swimming abilities displayed by some lines can increase severity of swim stress, masking the between-line differences or the main treatment effects.     

小儿的静脉穿刺与固定的护理体会

目的：探讨小儿大隐静脉、足背静脉输液用压舌板固定踝关节后再行静脉穿刺的临床效果。方法：200例输液患儿随机分成100例实验组和100例对照组,实验组采用固定踝关节后再行静脉穿刺,对照组用传统的静脉输液方法先穿刺后固定,观察两组穿刺成功例数、静脉固定时间和漏针次数。结果：实验组和对照组一针穿刺成功例数和两针或两针以上穿刺成功例数分别为88例、61例和12例、39例;实验组和对照组静脉固定时间分别为（68.9±11.5） s和（90.0±12.5） s;实验组和对照组漏针次数分别为12次和30次。两组比较,实验组一针穿刺成功例数与对照组比较有显著性差异（P＜0.05）,实验组较对照组一针穿刺成功例数多。实验组静脉固定时间与对照组比较有显著性差异（P＜0.05）,实验组较对照组静脉固定时间短。结论：大隐静脉、足背静脉输液用先固定再行静脉穿刺的方法,较传统的静脉输液方法在提高穿刺成功率、减少重复穿刺次数方面疗效好,值得推广。     

Effects of neonatal treatment with 5,7-dihydroxytryptamine or 6-hydroxydopamine on the ontogenetic development of the audiogenic immobility reaction in the rat

The ontogenetic development of the audiogenic immobility reaction (freezing) was studied in rats given intracisternal injections of the neurotoxins 5,7-dihydroxytryptamine (5,7-DHT), 25 g, or 6-hydroxydopamine (6-OHDA), 100 g, neonatally (Day 1). The duration of the freezing response was strongly reduced in the 5,7-DHT-treated rats between 20–30 days of age, when normal animals show very prolonged responses. During the same period increased motor activity was observed in the 6-OHDA-treated rats while only a slight reduction of the freezing response was noted. Biochemical analyses performed on brains from animals 35 days of age showed a selective reduction (about 50%) of whole brain levels of serotonin in the 5,7-DHT-treated rats, while the noradrenaline levels were selectively reduced by about 60% in the 6-OHDA rats. A longitudinal investigation on the effects of neonatal treatment with 5,7-DHT showed a persistent selective reduction of the whole brain level of serotonin up to at least 90 days of age. Since 5,7-DHT mainly affects the serotonergic pathways, the results suggest that the disturbances noted in the ontogeny of the freezing response may be due to interference with the developing serotonergic system.     

Effects of estrus, estrogen-progesterone priming, and vaginal stimulation on tonic immobility, dorsal immobility, and lordosis in the female rat

Three complex inhibitory responses, tonic immobility, the dorsal immobility response, and lordosis, were studied in the intact female rat during estrus and diestrus and in ovariectomized rats with estrogen-progesterone treatment or controls. In each condition, the effects of vaginal-cervical stimulation were also studied. The results of two experiments indicate that estrus and estrogen-progesterone treatment significantly potentiate lordosis and the dorsal immobility response with or without vaginal-cervical stimulation. Tonic immobility was also potentiated by estrus and estrogen-progesterone treatment, but only if vaginal-cervical stimulation was applied. Vaginal-cervical stimulation potentiated both tonic immobility and the dorsal immobility response, but not lordosis, which was already at a high level.     

Isoflurane-induced surgical tolerance mediated only in part by beta3-containing GABA(A) receptors

The targets which mediate the actions of the volatile general anaesthetic isoflurane are unknown. Based on pharmacological studies using GABA(A) receptor antagonists it has recently been suggested that GABA(A) receptors would not mediate the immobilizing action of isoflurane. Using the beta3(N265M) knock-in mouse model we found that the mutant mice were less sensitive to the immobilizing action of isoflurane, indicating a role of beta3-containing GABA(A) receptors in mediating immobility. At high concentrations isoflurane also immobilizes beta3(N265M) mice, indicating that other targets also mediate immobility. Thus, our findings support a multisite model for the immobilizing action of isoflurane.     

The thermal control of immobility in developing infant rats: Is the neocortex involved?

Infant rats aged 1 to 5 days lose heat rapidly when first exposed to room temperature; they also are initially very active and cannot be immobilized when turned over onto their sides and restrained for a few seconds. However, once core temperature drops closer to ambient levels, the stimulus for movement (rapid loss of heat from skin to environment) is diminished and immobility occurs. If the rapid heat loss, a source of apparent spontaneity, is prevented by precooling or continuous warmth, activity is blocked and prolonged restraint-related immobility can be readily produced. The warmed pups frequently made small twitches typical of those associated with paradoxical sleep. By 10 days, the pups can no longer be immobilized on their sides when pre-cooled, possibly because motor subsystems related to shivering thermogenesis (i.e., behaviors, including righting, that actively maintained a crouched upright position) begin to develop. At this age the pups can still be immobilized when warmed, but by 25 days of age slight warming is no longer effective because of the emergence of other sources of spontaneous locomotion that cannot be blocked by warmth, and/or because warmth can no longer induce paradoxical sleep. To test for the influence of the developing neocortex on immobility, pups were decorticated at 6 days of age. The activity and restraint immobility durations of the decorticate pups were not different from controls under any thermal condition at any postoperative age. Warmth-induced immboility was present following decortication in adult rats, but only in the early postoperative days, perhaps relating to subcortical diaschisis. It is suggested that the neocortex is not a major inhibitory influence on immobility induced by restraint.     

Systematic interrelationship of mating,vaginal plug position,and sperm transport in the rat

A quantitative means of evaluating the position of the vaginal plug in the vagina of the female rat was developed. Using this technique we demonstrated a systematic relationship between the position of the vaginal plug in the vagina, and sperm transport. The more fully the perimeter of the rostral end of the vaginal plug lodged in the vaginal-cervical junction, the greater was the transport of sperm from the vagina to the uterus. Secondly, males which maintained pelvic contact with the female for more than one sec after the final ejaculatory thrust deposited vaginal plugs which tended to fill three-fourths to the entire circumference of the vaginal-cervical junction. Males which maintained pelvic contact with the female for less than one sec after the final ejaculatory thrust deposited vaginal plugs which tended to fill one-half or less of the circumference of the vaginal-cervical junction. The protracted pelvic thrust shown by most males at ejaculation may cause the vaginal plug to lodge tightly in the vaginal-cervical junction.