Effects of N-acetylcysteine on amphetamine-induced sensitization in mice

Objective: N-acetylcysteine (NAC) is beneficial in psychiatric conditions, including schizophrenia. Patients with schizophrenia exhibit mesolimbic dopamine hyperfunction consequent to an endogenous sensitization process. This sensitization can be modeled in rodents by repeated exposure to psychostimulants, provoking an enduring amplified response at subsequent exposure. The aim of this study was to investigate the effects of NAC on amphetamine sensitization in mice. Methods: D-amphetamine was administered to C57BL/6 mice three times a week for 3 weeks; the dose was increased weekly from 1 to 3 mg/kg. NAC (60 mg/kg) or saline was administered intraperitoneally before saline or amphetamine during the second and third weeks. After a 4-week washout period, latent inhibition (LI) and the locomotor response to amphetamine 2 mg/kg were assessed. Results: Sensitization disrupted LI and amplified the locomotor response; NAC disrupted LI in control mice. In sensitized animals, NAC attenuated the enhanced locomotion but failed to prevent LI disruption. Conclusion: NAC warrants consideration as a candidate for early intervention in ultra-high risk subjects due to its safety profile and the relevance of its mechanism of action. Supplementing this proposition, we report that NAC attenuates sensitization-induced locomotor enhancement in mice. The finding that NAC disrupted LI incites a cautionary note and requires clarification

Somatic embryogenesis and in vitro plantlet regeneration of Lilium martagon L. var. cattaniae Vis.

In this study organogenic capacity of two different explants type (leaves and whole bulbs) of Lilium martagon L. var. cattaniae Vis. was examined. For induction of in vitro somatic embryogenesis and adventitive regeneration different concentrations of 2,4-dichlorophenoxyacetic acid and 6-benzilaminopurine (from 0,25 mg/l to 8,00 mg/l) added to MS basal medium were used. Our results indicate that concentration of 0,5 mg/l 2,4-dichlorophenoxyacetic acid and 4 mg/l 6- benzilaminopurine promoted somatic embryogenesis from leaves of Lilium martagon var. cattaniae, while all other concentrations promoted direct shoot regeneration from bulb explants. Root formation was induced on MS basal medium with 0,2 mg/l indole butyric acid. These plantlets were acclimatized well in a greenhouse conditions

Self-rated intensity of habitual physical activities is positively associated with dopamine D-2/3 receptor availability and cognition

Available online: 21 July 2018Between-person differences in cognitive performance in older age are associated with variations in physical activity. The neurotransmitter dopamine (DA) contributes to cognitive performance, and the DA system deteriorates with advancing age. Animal data and a patient study suggest that physical activity modulates DA receptor availability, but data from healthy humans are lacking. In a cross-sectional study with 178 adults aged 64-68 years, we investigated links among self-reported physical activity, D(2/3)DA receptor (D2/3DR) availability, and cognitive performance. D2/3DR availability was measured with [C-11]raclopride positron emission tomography at rest. We used structural equation modeling to obtain latent factors for processing speed, episodic memory, working memory, physical activity, and D2/3DR availability in caudate, putamen, and hippocampus. Physical activity intensity was positively associated with D2/3DR availability in caudate, but not putamen and hippocampus. Frequency of physical activity was not related to D2/3DR availability. Physical activity intensity was positively related to episodic memory and working memory. D2/3DR availability in caudate and hippocampus was positively related to episodic memory. Taken together, our results suggest that striatal DA availability might be a neurochemical correlate of episodic memory that is also associated with physical activity.Swedish Research Council [446-2013-7189]FORTE [2013-2277]Umea UniversityUmea University-Karolinska Institute Strategic Neuroscience programKnut and Alice Wallenberg Foundationgs5:Torsten and Ragnar Soderberg FoundationAlexander von Humboldt Research awardSwedish Brain PowerSwedish Brain FoundationVasterbotten County CouncilMax Planck SocietyGerman Research Foundation (DFG