Cognitive improvements in a rat model with polyunsaturated fatty acids EPA and DHA through α7-nicotinic acetylcholine receptors.

The α7-nicotinic acetylcholine receptor (α7-nAChR) is a recognized target for the treatment of dementia associated with aging and certain developmental disorders. This study evaluates memory improvement in a rat model by the effects of polyunsaturated fatty acids EPA and DHA mediated by α7-nAChR, as well as identifying the minimum dose of EPA/DHA required to generate an effect in the improvement of cognition through α7-nAChR in rats. The modified Y-maze and object recognition behavioral tests were performed in scopolamine-induced amnesic rats, in order to study the effects of long-term supplementation (10, 15, 30, and 60 mg/kg) of the two polyunsaturated fatty acids in improving cognitive impairment. Cognitive enhancement by EPA and DHA is mediated through α7-nAChRs, as evidenced by memory recovery after treatment with a selective α7-nAChR antagonist, methyllycaconitine (MLA). Tacrine, a centrally active acetylcholinesterase inhibitor, and PNU282987, an α7-nAChR agonist, are employed as reference standards. Our data demonstrate that 15 mg/kg EPA and DHA can affect cholinergic neurotransmission positively through memory and cognition and, thus, can exert a beneficial action on learning and memory deficits.

Ornithobacterium rhinotracheale: An Update Review about An Emerging Poultry Pathogen.

Respiratory diseases in birds generate sanitary and economic impacts and may be related to the environment and climate. Mycoplasma gallisepticum, Ornithobacterium rhinotracheale (ORT), Pasteurella multocida, Avibacterium paragallinarum, Escherichia coli, Riemerella anatipestifer, and Bordetella avium are among the most important avian respiratory pathogens. ORT is responsible for causing ornitobacteriosis, a disease characterized by clinical signs ranging from mild to severe respiratory conditions, with high mortality rates, mainly affecting turkeys and chickens. The first report of ornitobacteriosis was in 1981 in Germany. Despite its importance, few studies on ORT have been published. In addition, the presence of this pathogen has been neglected in poultry farms, mainly due to the lack of appropriate diagnostic protocols. The lack of correct isolation and diagnostic protocols along with inappropriate use of antimicrobial agents have been contributing to treatment failure. Due to its economic importance to the poultry industry, ornitobacteriosis should be monitored and included in national programs for the prevention and control of avian respiratory diseases. This review aimed to update and discuss important issues related to ORT since this pathogen has great economic and sanitary implications for the chicken production chain.

Neuroprotective effects of swimming training in a mouse model of Parkinson's disease induced by 6-hydroxydopamine.

Parkinson's disease (PD) is characterized by progressive dopamine (DA) depletion in the striatum. Exercise has been shown to be a promising non-pharmacological approach to reduce the risk of neurodegeneration diseases. This study was designed to investigate the potential neuroprotective effect of swimming training (ST) in a mouse model of PD induced by 6-hydroxydopamine (6-OHDA) in mice. The present study demonstrated that a 4-week ST was effective in attenuating the following impairments resulting from 6-OHDA exposure: (i) depressive-like behavior in the tail suspension test; (ii) increase in the number of falls in the rotarod test; (iii) impairment on long-term memory in the object recognition test; (iv) increase of the reactive species and interleukin 1-beta (IL-1ß) levels; (v) inhibition of the glutathione peroxidase (GPx) activity; (vi) rise of the glutathione reductase (GR) and glutathione S-transferase (GST) activities and vii) decrease of DA, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) levels. The mechanisms involved in this study are the modulation of GPx, GR and GST activities as well as IL-1ß level in a PD model induced by 6-OHDA, protecting against the decrease of DA, DOPAC and HVA levels in the striatum of mice. These findings reinforce that one of the effects induced by exercise on neurodegenerative disease, such as PD, is due to antioxidant and anti-inflammatory properties. We suggest that exercise attenuates cognitive and motor declines, depression, oxidative stress, and neuroinflammation induced by 6-OHDA supporting the hypothesis that exercise can be used as a non-pharmacological tool to reduce the symptoms of PD.

Divergent short- and long-term effects of acute stress in object recognition memory are mediated by endogenous opioid system activation.

Acute stress induces short-term object recognition memory impairment and elicits endogenous opioid system activation. The aim of this study was thus to evaluate whether opiate system activation mediates the acute stress-induced object recognition memory changes. Adult male Wistar rats were trained in an object recognition task designed to test both short- and long-term memory. Subjects were randomly assigned to receive an intraperitoneal injection of saline, 1 mg/kg naltrexone or 3 mg/kg naltrexone, four and a half hours before the sample trial. Five minutes after the injection, half the subjects were submitted to movement restraint during four hours while the other half remained in their home cages. Non-stressed subjects receiving saline (control) performed adequately during the short-term memory test, while stressed subjects receiving saline displayed impaired performance. Naltrexone prevented such deleterious effect, in spite of the fact that it had no intrinsic effect on short-term object recognition memory. Stressed subjects receiving saline and non-stressed subjects receiving naltrexone performed adequately during the long-term memory test; however, control subjects as well as stressed subjects receiving a high dose of naltrexone performed poorly. Control subjects' dissociated performance during both memory tests suggests that the short-term memory test induced a retroactive interference effect mediated through light opioid system activation; such effect was prevented either by low dose naltrexone administration or by strongly activating the opioid system through acute stress. Both short-term memory retrieval impairment and long-term memory improvement observed in stressed subjects may have been mediated through strong opioid system activation, since they were prevented by high dose naltrexone administration. Therefore, the activation of the opioid system plays a dual modulating role in object recognition memory.