Publications by authors named "Bengt Meyerson"

Widespread traumatic axonal injury (TAI) results in brain network dysfunction, which commonly leads to persisting cognitive and behavioural impairments following traumatic brain injury (TBI). TBI induces a complex neuroinflammatory response, frequently located at sites of axonal pathology. The role of the pro-inflammatory cytokine interleukin (IL)-1β has not been established in TAI.

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Background: Diffuse traumatic axonal injury (TAI), a common consequence of traumatic brain injury, is associated with high morbidity and mortality. Inflammatory processes may play an important role in the pathophysiology of TAI. In the central fluid percussion injury (cFPI) TAI model in mice, the neuroinflammatory and astroglial response and behavioral changes are unknown.

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Chronic stress and its concomitant neurobiological consequences are, in all probability, provocateurs of mental disease in humans. To gain some insight into the provocative effects of stress on hormonally dependent conditions, we developed a rat model that combines social subordinate housing (SSH) with withdrawal from combined progesterone (P) and estradiol (E) treatment (PEWD). At the start of the experiment, male Wistar rats were housed in triads consisting of one younger rat (35 days old) and two older rats (55 days old), with the intent of producing subordination stress in the younger animals.

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There is a need for more efficient tests to evaluate functional outcome following experimental traumatic brain injury (TBI), reflecting deficits in cognitive, sensory, and motor functions that are seen in TBI patients. The Multivariate Concentric Square Field (MCSF) test is a relatively new behavioral model that measures exploration, risk taking, risk assessment, and shelter seeking, all of which are evolutionarily-conserved strategies for survival. The multivariate design enables scoring of different functional domains in a single test situation, with a free choice of optional environmental settings.

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Pancreatic polypeptide (PP) belongs to the neuropeptide Y (NPY) family of peptides and is released from pancreatic F cells postprandially. PP functions as a peptide hormone and has been associated with decreased food intake in humans and rodents. Our study describes the effects of PP on feeding behavior in dogs, whose mammalian order (Carnivora) is more distantly related to primates and rodents than these are to each other.

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Withdrawal from progesterone and estradiol has been used as an animal model of premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). In the clinical population individual sensitivity to sex steroid hormones, personality and heredity influence PMS/PMDD. Understanding the phenotypic risk factors of PMS/PMDD and drug development requires an animal model which incorporates individual steroid sensitivity.

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The aim of the present investigation was to compare the behavioural profiles in alcohol-preferring AA (Alko, alcohol) and alcohol-avoiding ANA (Alko, non-alcohol) rats. Twelve adult, alcohol-naïve male AA and ANA rats were tested in the recently established multivariate concentric square field (MCSF) test. The more traditional open field and elevated plus-maze tests were used as reference tests.

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Allopregnanolone (3alpha-hydroxy-5alpha-pregnane-20-one) is a ring-A-reduced metabolite of progesterone, which is naturally produced during the luteal phase of the menstrual cycle, during pregnancy and by stressful events. The steroid hormone inhibits neural functions through increased chloride ion flux through the GABA(A) receptor. The effects and subsequent withdrawal symptoms are similar to those caused by alcohol, benzodiazepines and barbiturates.

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Clinical studies have demonstrated that growth hormone (GH) promotes learning and memory processes in GH-deficient (GHD) patients. In animal studies, GH also influences the N-methyl-D-aspartate (NMDA) receptor system in the hippocampus, an essential component of long-term potentiation (LTP), which is highly involved in memory acquisition. This study was designed to examine the beneficial effects of recombinant human GH (rhGH) on cognitive function in male rats with multiple hormone deficiencies resulting from hypophysectomy (Hx).

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The estrous cycle, with its various hormonal conditions, may provide us with the means of understanding how endocrine states relate to opioid mechanisms. There has been increasing experimental support for interaction between sex steroids and opioid peptides in the central nervous system. Here, we describe fluctuations in endogenous brain immunoreactive (ir) peptide levels during various phases of the estrous cycle in the female Sprague-Dawley rat.

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In this study, we describe the behavior of laboratory rats in a recently developed observation arena, the Concentric Square Field (CSF). The CSF contains a number of areas designed to provoke exploration and behaviors associated with risk assessment, risk taking and security seeking in an environment not previously experienced. The model includes sheltered, open and elevated areas, a hole board device, areas with different light conditions, and wall-enclosed corridors.

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In an evolutionary prospective, it is possible that female mice have a differential perception of novel events than male mice and use a different behavioural strategy for risk assessment. However, female mice are less studied than male mice in behavioural tests of emotional reactivity. The aim of the present study was to investigate how wild-derived female house mice differ from domesticated female mice in their risk assessment strategy.

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The ability to gather information and assess risks in novel environments is crucial for survival and fitness in the wild. Our aim was to characterise behavioural strategies of exploration and risk assessment in novel environments and to investigate in what respects wild house mice differ from domesticated mice. A total of 39 adult male mice from three genetic backgrounds (Wild, BALB/c, and C57BL/6) were tested in three behavioural tests, the concentric square field (CSF), a modified open field (OF), and a conventional elevated plus maze (EPM).

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This study investigates the effects of cerebral microembolism on motor performance and risk assessment behavior in the rat. Cerebral infarcts were produced in rats by injecting small plastic beads into the left heart ventricle under short-acting anesthesia. The functional outcome was tested 24 h later by subjecting the animals to a series of consecutive behavioral tests.

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