Abstracts: AAOMPT Conference, 2006

Abstract

This case report describes the effectiveness of mechanical diagnosis and therapy (MDT) in the management of a patient referred with a diagnosis of shoulder tendonitis. The patient was a 56-year-old male with a 3-month history of left anterior shoulder pain. Upon initial assessment, he presented with a positive open-can test, lift-off test, and Hawkins–Kennedy impingement test. A MDT assessment quickly ruled out cervical involvement and identified a loss of end-range shoulder mobility and pain during active shoulder movement. After the patient underwent a repeated movement examination and treatment based on responses to end-range movements over three visits, his shoulder pain was abolished and motion was fully restored. Despite having positive rotator cuff and impingement signs, this patient was effectively treated with repeated end-range movements over a short period of 2 weeks. This case demonstrates that treatment based on MDT sub-classification principles may be an effective way to manage shoulder pain as it is in the spine.     

Delays to Reward Delivery Enhance the Preference for an Initially Less Desirable Option: Role for the Basolateral Amygdala and Retrosplenial Cortex

Temporal costs influence reward-based decisions. This is commonly studied in temporal discounting tasks that involve choosing between cues signaling an imminent reward option or a delayed reward option. However, it is unclear whether the temporal delay before a reward can alter the value of that option. To address this, we identified the relative preference between different flavored rewards during a free-feeding test using male and female rats. Animals underwent training where either the initial preferred or the initial less preferred reward was delivered noncontingently. By manipulating the intertrial interval during training sessions, we could determine whether temporal delays impact reward preference in a subsequent free-feeding test. Rats maintained their initial preference if the same delays were used across all training sessions. When the initial less preferred option was delivered after short delays (high reward rate) and the initial preferred option was delivered after long delays (low reward rate), rats expectedly increased their preference for the initial less desirable option. However, rats also increased their preference for the initial less desirable option under the opposite training contingencies: delivering the initial less preferred reward after long delays and the initial preferred reward after short delays. These data suggest that sunk temporal costs enhance the preference for a less desirable reward option. Pharmacological and lesion experiments were performed to identify the neural systems responsible for this behavioral phenomenon. Our findings demonstrate the basolateral amygdala and retrosplenial cortex are required for temporal delays to enhance the preference for an initially less desirable reward.SIGNIFICANCE STATEMENT The goal of this study was to determine how temporal delays influence reward preference. We demonstrate that delivering an initially less desirable reward after long delays subsequently increases the consumption and preference for that reward. Furthermore, we identified the basolateral amygdala and the retrosplenial cortex as essential nuclei for mediating the change in reward preference elicited by sunk temporal costs.     

Contextual fear extinction ameliorates sleep disturbances found following fear conditioning in rats

STUDY OBJECTIVE: To examine the effects of fear extinction on subsequent sleep in rats and to compare it with the effects seen following contextual reminders of fear. DESIGN: Habituation of the rats to handling and baseline recordings were obtained over 2 consecutive days. Afterward, the rats were subjected to shock training (ST; day 1), context reexposure (CR; either 30 or 60 min; day 2), and fear recall (R; day 3). Percentage time spent in freezing (FT%) was observed during ST, CR, and R exposures. Sleep was recorded for 20 h (8-h light and 12-h dark period) following ST, CR, and R. SETTING: NA SUBJECTS: The subjects were outbred Wistar rats randomly assigned to one of two groups: contextual fear (FR; n = 7) or contextual extinction (EXT; n = 7). INTERVENTIONS: The rats were surgically implanted with electrodes for recording the electroencephalogram and electromyogram for determining arousal state. MEASUREMENTS AND RESULTS: There were no differences between groups on FT% during ST or the first 30 min of CR; however, during R, the FR group had greater FT% than EXT. Sleep did not differ between groups following ST. Following CR, EXT exhibited significantly more total sleep, NREM, and REM than FR. After R, there were no differences between groups. CONCLUSIONS: Rats that exhibit extinction of contextual fear show significantly increased sleep compared to rats who continue to exhibit contextual fear. This suggests that sleep disturbances normally experienced in humans following traumatic events or reminders may be ameliorated by therapies that address and eliminate the associated fear.     

Enhanced neural activation in brain regions mediating sexual responses following exposure to a conditioned stimulus that predicts copulation

Stimuli associated with sexual behavior increase reproductive success if presented prior to copulation. In Japanese quail, inseminations that take place in a context that predicts the arrival of a female are more likely to result in fertilized eggs. We demonstrate here that in male Japanese quail a sexual conditioned stimulus (CS) also enhances activity in two brain regions that mediate sexual behavior, the medial preoptic area and the medial part of the bed nucleus of the stria terminalis. C-fos expression, a marker of neural activation, was higher in these areas in subjects exposed sequentially to a sexual CS and copulation than in subjects exposed to copulation or the CS alone or in subjects exposed to no sexual stimulus, either an identical, untrained CS or an empty arena. These results suggest a link between a proximate result of sexual CS presentation, male brain activation, and a known ultimate outcome, increased fertilizations.     

Effects of nitrous oxide on dopamine release in the rat nucleus accumbens and expectation of reward

Recently we have shown that nitrous oxide (N2O) was able to block the expression of morphine-induced conditioned place preference (CPP) in mice. Because dopamine (DA) has also been associated with the positive place conditioning we hypothesize that exposure to N2O would be significantly associated with a modification of extracellular level of DA. Unbiased place conditioning method was used for mice and rats. Levels of DA, in the nucleus accumbens (Nac), in awake and freely moving rats during positive place conditioning after morphine chronic treatment has been measured by microdialysis. Expression of morphine-induced CPP was totally abolished in mice and rats exposed to N2O. Results of animals placed in the morphine-paired compartment showed a 75% increase in the extracellular levels of DA, which was blocked by exposure of animals to N2O. In conclusion we showed the capacity of N2O to block the expression of morphine-induced CPP in mice and in rats. Then we demonstrated an increase of DA extracellular level in the Nac when animals were placed in the morphine-paired compartment and these increase of DA level was blocked by N2O.     

Enhancement of anxiety, facilitation of avoidance behavior, and occurrence of adult-onset obesity in mice lacking mitochondrial cyclophilin D

In this report, we have assessed the behavioral responses of mice missing the Ppif gene (CyPD-KO), encoding mitochondrial cyclophilin D (CyPD). Mitochondrial CyPD is a key modulator of the mitochondrial permeability transition which is involved in the regulation of calcium- and oxidative damage-induced cell death. Behavioral screening of CyPD-KO mice (ranging between 4 and 15 months of age) was accomplished using a battery of behavioral paradigms which included testing of motor functions, exploratory activity, and anxiety/emotionality, as well as learning and memory skills. We found that, compared with wild-type mice, CyPD-KO mice were (i) more anxious and less explorative in open field and elevated plus maze and (ii) performed better in learning and memory of avoidance tasks, such as active and passive avoidance. However, the absence of CyPD did not alter the nociceptive threshold for thermal stimuli. Finally, deletion of CyPD caused also an abnormal accumulation of white adipose tissue resulting in adult-onset obesity, which was not dependent on increased food and/or water intake. Taken together, our results suggest a new fundamental role of mitochondrial CyPD in basal brain functions and body weight homeostasis.     

Olfactory experience and the development of odor preference and vaginal marking in female Syrian hamsters

Rodent reproductive behavior relies heavily on odor processing, and evidence suggests that many odor-guided sexual behaviors are shaped by prior experience. We sought to determine if exposure to male odors during development is required for the adult expression of proceptive sexual behavior toward male odors in female Syrian hamsters. Exposure to male odors was restricted in na?ve subjects by removing all male siblings from the litter at three to five days of age. Control litters were also culled, but included equal numbers of male and female pups. As adults, na?ve females displayed investigatory preferences toward male odors in a Y-maze that were comparable to control females; this preference was observed whether contact with the odor stimuli was prevented of allowed. In contrast, na?ve females vaginal scent-marked equally toward male and female volatile odors, suggesting an inability to target behavior toward sexually relevant odors. However, na?ve females marked preferentially toward male odors when allowed to contact the odor stimuli. These results provide evidence for the experience-dependent development of vaginal marking behavior toward volatile components of sexual odors. Furthermore, they suggest that distinct mechanisms regulate the development of odor preferences and vaginal marking behavior in this species.     

Exposure to PCB 77 affects partner preference but not sexual behavior in the female rat

In rats, exposure to the polychlorinated biphenyl congener 3, 4, 3′, 4′-tetrachlorobiphenyl (PCB 77) affects the brain and behavior of the offspring as well as the maternal behavior of the dams. In the present study, a cross-fostering design was used to examine the effects of pre- and/or postnatal exposure to PCB 77 on sexual behavior and partner preference in female rats, and to determine the role of altered maternal behavior in the mediation of these effects. Pregnant rats were treated with oil or PCB dissolved in oil (2 mg/kg b.w.) on gestation days 6-18 and then given pups that had been exposed to either the oil vehicle or PCB during gestation. As adults, the female offspring were tested for partner preference (that is, whether they preferred to spend time with a sexually receptive female or a sexually active male) and sexual behavior. None of the treatments affected female sexual behavior. However, both double exposure and postnatal exposure diminished the animals' preference for a male over a female stimulus, but partner preference was not affected by prenatal exposure alone. There were no significant correlations between the changes in partner preferences due to PCB exposure and the amount of maternal grooming and licking received by the treated litters. Thus, female partner preference is affected by early PCB exposure, and the effects depend upon whether the exposure is in utero or via lactation and may be independent of any effects of the PCB on maternal care.     

Allocentric and egocentric reference frames in the processing of three-dimensional haptic space

In an earlier experiment we showed that selective attention plays a critical role in rabbit eye blink conditioning (Steele-Russell et al. in Exp Brain Res 173:587–602, 2006). The present experiments are concerned to examine the extent to which visual recognition processes are a separate component from the motor learning that is also involved in conditioning. This was achieved by midline section of the optic chiasma which disconnected the direct retinal projections via the brainstem to the cerebellar oculomotor control system. By comparing both normal and chiasma-sectioned rabbits it was possible to determine the dependence or independence of conditioning on the motor expression of the eye blink response during training. Both normal and chiasma-sectioned animals were tested using a multiple test battery to determine the effect of this redirection of the visual input pathways on conditioning. All animals were first tested for any impairment in visual capability following section of the optic chiasma. Despite the loss of 90% of retinal ganglion cell fibres, no visual impairment for either intensity or pattern vision was seen in the chiasma animals. Also no difference was seen in nictitating membrane (NM) conditioning to an auditory signal between normal and chiasma animals. Testing for motor learning to a visual signal, the chiasma rabbits showed a complete lack of any NM conditioning. However the sensory tests of visual conditioning showed that chiasma-sectioned animals had completely normal sensory recognition learning. These results show that NM Pavlovian conditioning involves anatomically separate and independent sensory recognition and motor output components of the learning. This research was supported by S&W research grants ID# 1810 to ISR and ID# 7985 to JAC.     

饮食偏好及行为对中小学生超重或肥胖影响的病例对照研究

目的 探讨饮食偏好及行为对中小学生超重或肥胖的影响.方法 采用病例对照研究方法,病例为广州市28所中小学中年龄为6～19岁的所有超重或肥胖学生,对照为同校同年级随机抽取的1～2个班中所有体重正常者.饮食偏好和行为采用自编问卷调查,对饮食偏好和行为按由少到多或由不喜欢到喜欢分为4个水平;通过测胃身高和体重计算BMI并进行营养状况的分类;采用两分类logistic回归分析筛选中小学牛超重或肥胖的影响因素. 结果 共调查7136人,问卷有效者5755人中超重或肥胖者为1947人,体重正常者2136人.单因素分析超重或肥胖的风险,很喜炊吃蔬菜、水果或糖果及夜宵者是不喜欢者的0.60～0.69倍;对食物挑剔多者是极少挑剔者的0.50倍;而很喜炊吃猪肉、牛羊肉和油炸食物者分别是不喜欢者的1.84、1.30和1.26倍;以及吃饭速度快者足慢者的5.14倍(P值均<0.05).在控制年龄、性别、家庭社会经济因素、父母体型后,对蔬菜与夜宵的偏好、挑剔食物以及进食速度4个指标对超重或肥胖的影响依然具有统计学意义.与不喜欢蔬菜或夜宵、不挑剔食物或进食速度慢者相比,喜欢蔬菜或夜宵、挑剔食物、进食速度快者对超重或肥胖影响的比值比(OR)及95%CI分别为0.55(0.42～0.73),0.48(0.35～0.65),0.50(0.39～0.65)和4.32(3.23～5.80). 结论 减慢进食速度与多吃蔬菜有利于预防中小学生超重或肥胖.