Amygdala and periaqueductal gray lesions only partially attenuate unconditional defensive responses in rats exposed to a cat

Defensive responses to a cat were observed in rats given excitotoxic lesions of the central nucleus of the amygdala (ACe), dorsolateral periaqueductal gray (dlPAG), ventral periaqueductal gray (vPAG), or sham lesions. Rats were placed adjacent to a compartment containing a cat. Sham-lesioned rats avoided the area nearest the cat and preferred the area furthest away from the cat. They also exhibited numerous defensive responses including, climbing, escape from the apparatus, and freezing. Rats with lesions of the ACe reacted like the sham lesioned rats by preferring the area of the apparatus furthest from the cat, however they climbed and escaped significantly less than sham lesioned rats. Avoidance of the area adjacent to the cat was attenuated in rats with lesions of the vPAG. Climbing along the walls of the apparatus was also attenuated in rats with lesions of the vPAG. Escapes from the apparatus were not significantly reduced by lesions of the vPAG and dlPAG. Thus, ACe lesions attenuated climbing and eliminated escapes, but did not impair locomotion of the rat away from the cat.     

Changes in anabolic and catabolic activity among women taking part in an alternative labour market programme

Thirty-two female participants in a mobilising labour market programme offering temporary, alternative employment in Sweden were followed longitudinally for one year, including a six month post participation follow-up period. It can be hypothesised that an important aspect of the physiological effects of unemployment is a change in the balance between anabolic and catabolic activities in the body and that re-employment should lead to a shift towards anabolism. An earlier study of a smaller subset of the data, however, including both men and women, showed increased prolactin and decreased dehydroepiadrosterone sulphate (DHEA-s) levels, contrary to the initial hypothesis. In the present analysis, intended to elucidate these results, psychophysiological data were summarised in two indices, one connected with anabolism (made up of testosterone and DHEA-s) and one with catabolism (prolactin, γ-glutamyl transferase, aspartate amino transferase, α levuline amino transferase, and body mass index). In addition, self-rated anxiety, depression, hopelessness and personal control were analysed. The results indicate that the effect of ‘better’ activities within the programme was a temporary increase in anabolism, possibly indicating lower stress levels, and the effect of ‘worse’ activities, on the one hand, a temporary decrease in the catabolic index, probably reflecting repressed alcohol consumption, and, on the other hand, impaired anabolism. There was also a general but transient decrease in depressiveness measured by the Hospital Anxiety and Depression Scale. The results seem to imply that it is difficult to achieve lasting effects through a relatively short participation in a mobilising programme.     

An evaluation of the ability to voluntarily reduce the heart rate after a month of yoga practice

The study aimed at determining whether novices to yoga would be able to reduce their heart rate voluntarily and whether the magnitude of reduction would be more after 30 days of yoga training. Two groups (yoga and control,n=12 each) were assessed on Day 1 and on Day 30. During the intervening 30 days, the yoga group received training in yoga techniques while the control group carried on with their routine. At each assessment the baseline heart rate was recorded for one minute, this was followed by a six-minute period during which participants were asked to attempt to voluntarily reduce their heart rate, using any strategy. Both the baseline heart rate and the lowest heart rate achieved voluntarily during the six-minute period were significantly lower in the yoga group on Day 30 compared to Day 1 by a group average of 10.7 beats per minute (i.e., bpm) and 6.8 bpm, respectively (p<.05, Wilcoxon paired signed ranks test). In contrast, there was no significant change in either the baseline heart rate or the lowest heart rate achieved voluntarily in the control group on Day 30 compared to Day 1. The results suggest that yoga training can enable practitioners to use their own strategies to reduce the heart rate, which has possible therapeutic applications.     

Differential mastication kinematics of the rabbit in response to food and water: Implications for conditioned movement

Analysis of naturalistic chewing patterns may provide insight into mapping the neural substrates of jaw movement control systems, including their adaptive modification during the classically conditioned jaw movement (CJM) paradigm. Here, New Zealand White rabbits were administered food and water stimuli orally to evaluate the influence of stimulus consistency on masticatory pattern. Chewing patterns were recorded via video camera and movements were analyzed by computerized image analysis. The mandibular kinematics, specifically the extent of dorsal/ventral, medial/lateral, and rostral/caudal movement, were significantly larger in food-evoked than water-evoked chewing. Water-evoked chewing frequency, however, was significantly higher than that of food-evoked movements. In light of known cortical mastication modulatory centers, our findings implicate different neural substrates for the responses to food and water stimuli in the rabbit. A detailed delineation of jaw movement patterns and circuitry is essential to characterize the neural substrates of CJM.     

Is traumatic amnesia nothing but psychiatric folklore?

Some psychotherapists believe that certain experiences are so overwhelmingly traumatic that some victims become incapable of remembering their worst trauma except under special circumstances (e.g. therapy) many years later. Unfortunately, clinicians who endorse this concept of traumatic amnesia often misinterpret the very studies they adduce in support of it. More specifically, they misinterpret other, unrelated memory phenomena as evidence for traumatic amnesia, such as ordinary forgetfulness, psychogenic amnesia, organic amnesia, incomplete encoding of traumatic experiences, non-disclosure of remembered trauma, and simply not thinking about something for a long time. The purpose of this article is to dispel confusions rampant in this literature.     

Biomedical, ethical, and moral issues being forced by advanced medical technologies

Technology is rampant, exponentially growing beyond the bounds normally comprehensible by the human mind. Many of these technologies are so fundamentally disruptive that they challenge the very practice of science. Discoveries once unimaginable except in science fiction are appearing at such a rapid rate that there is no time to evaluate their moral and ethical implications in a deliberate and measured fashion. Genetic engineering, human cloning, tissue engineering, intelligent robotics, nanotechnology, suspended animation, regeneration, and species prolongation are but a few that will revolutionize what it means to be human and what the ultimate fate of the species may be. Unless these issues are addressed at this time, we shall face the consequences of an uncontrolled and unprepared future.     

Cognitive behaviour therapy of acute stress disorder: a four-year follow-up

The aim of this study was to index the long-term benefits of early provision of cognitive behavior therapy to trauma survivors with acute stress disorder. Civilian trauma survivors (n = 80) with acute stress disorder were randomly allocated to either cognitive behavior therapy (CBT) or supportive counseling (SC) - 69 completed treatment, and 41 were assessed four years post-treatment for post-traumatic stress disorder (PTSD) with the Clinician Administered PTSD Scale. Two CBT patients (8%) and four SC patients (25%) met PTSD criteria at four-year follow-up. Patients who received CBT reported less intense PTSD symptoms, and particularly less frequent and less avoidance symptoms, than patients who received SC. These findings suggest that early provision of CBT in the initial month after trauma has long-term benefits for people who are at risk of developing PTSD.