Amphetamine-induced c- fos mRNA expression in the caudate-putamen and subthalamic nucleus: interactions between dose, environment, and neuronal phenotype

When administered in a novel environment relatively low doses of amphetamine induce c- fos mRNA in the subthalamic nucleus (STN) and in preproenkephalin mRNA-containing (ENK+) neurons in the caudate-putamen (CPu). When administered at home, however, low doses of amphetamine do not produce these effects. Environmental novelty also facilitates the behavioral effects of acute and repeated amphetamine, but this is dose-dependent. The purpose of the present experiment therefore was to determine if the effect of context on amphetamine-induced c- fos expression is also dose-dependent. It was found that: (i) No dose of amphetamine tested (1–10 mg/kg) induced c- fos in many ENK+ cells when given at home. (ii) When given in a novel environment low to moderate doses of amphetamine (1–5 mg/kg) induced c- fos in substantial numbers of ENK+ cells, but the highest dose examined (10 mg/kg) did not. (iii) Environmental novelty enhanced the ability of low to moderate doses of amphetamine to induce c- fos in the STN, but the highest dose of amphetamine induced robust c- fos mRNA expression in the STN regardless of context. The results do not support the idea that engaging ENK+ cells, at least as indicated by c- fos mRNA expression, is critical to produce robust behavioral sensitization, but do suggest a possible role for the STN. Furthermore, the results highlight the importance of drug–environment interactions on the neurobiological effects of drugs, and have implications for thinking about the circuits by which context modulates the acute and long-lasting consequences of amphetamine treatment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66354/1/j.1471-4159.2003.01646.x.pd

Prey Records for the Eastern Indigo Snake (Drymarchon couperi)

Prey items for the federally protected Eastern Indigo Snake (Drymarchon couperi) were compiled from published and gray literature, field observations, necropsies, dissection of museum specimens, and personal communications from reliable sources. One hundred and eighty-six records were obtained for 48 different prey species. Anurans, Gopher Tortoises, snakes, and rodents comprised ca. 85% of the prey items. Most records (n = 143) that mentioned size were from adult indigos; 17 were from juveniles. Prey records were collected from 1940-2008 and were available for all months of the year. These data confirm that Eastern Indigo Snakes eat a wide assortment of prey of varying sizes. This strategy allows D. couperi to potentially forage successfully in many different types of habitats and under fluctuating environmental conditions, a valuable trait for a top-level predator that requires a large home range

Amphetamine and cocaine induce different patterns of c- fos mRNA expression in the striatum and subthalamic nucleus depending on environmental context

In the dorsal striatum, there are two major populations of medium spiny projection neurons. One population is positive for dynorphin mRNA (DYN+), and these cells project preferentially to the substantia nigra, forming the so-called ‘direct pathway’. A second population is positive for enkephalin mRNA (ENK+), and these cells influence the substantia nigra indirectly, via the globus pallidus and subthalamic nucleus. Psychostimulant drugs, such as amphetamine and cocaine, are reported to induce immediate early genes (IEGs) in only one subpopulation of dorsal striatal projection neurons, DYN+ cells. However, this apparent selectivity appears to be a function of environmental context. We found that when given in the animal's home cage, amphetamine and cocaine increased expression of the IEG, c- fos , almost exclusively in DYN+ cells. However, when given in a novel environment, amphetamine and cocaine increased c- fos mRNA in both DYN+ and ENK+ cells. Furthermore, amphetamine and cocaine increased c- fos mRNA expression in the subthalamic nucleus when administered in the novel environment, but not when given at home. We conclude that the neural circuitry engaged by psychostimulant drugs, and their ability to induce specific patterns of gene expression, are determined by the environmental context in which they are experienced. This may be related to the ability of environmental novelty to facilitate psychostimulant drug-induced neuroplasticity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75267/1/j.0953-816x.2001.01574.x.pd

DNA Targeting as a Likely Mechanism Underlying the Antibacterial Activity of Synthetic Bis-Indole Antibiotics

We previously reported the synthesis and biological activity of a series of cationic bis-indoles with potent, broad-spectrum antibacterial properties. Here, we describe mechanism of action studies to test the hypothesis that these compounds bind to DNA and that this target plays an important role in their antibacterial outcome. The results reported here indicate that the bis-indoles bind selectively to DNA at A/T-rich sites, which is correlated with the inhibition of DNA and RNA synthesis in representative Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) organisms. Further, exposure of E. coli and S. aureus to representative bis-indoles resulted in induction of the DNA damage-inducible SOS response. In addition, the bis-indoles were found to be potent inhibitors of cell wall biosynthesis; however, they do not induce the cell wall stress stimulon in S. aureus, suggesting that this pathway is inhibited by an indirect mechanism. In light of these findings, the most likely basis for the observed activities of these compounds is their ability to bind to the minor groove of DNA, resulting in the inhibition of DNA and RNA synthesis and other secondary effects

Amphetamine-evoked c- fos mRNA expression in the caudate-putamen: the effects of DA and NMDA receptor antagonists vary as a function of neuronal phenotype and environmental context

Dopamine (DA) and glutamate neurotransmission is thought to be critical for psychostimulant drugs to induce immediate early genes (IEGs) in the caudate-putamen (CPu). We report here, however, that the ability of DA and glutamate NMDA receptor antagonists to attenuate amphetamine-evoked c- fos mRNA expression in the CPu depends on environmental context. When given in the home cage, amphetamine induced c- fos mRNA expression predominately in preprodynorphin and preprotachykinin mRNA-containing neurons (Dyn-SP+ cells) in the CPu. In this condition, all of the D1R, D2R and NMDAR antagonists tested dose-dependently decreased c- fos expression in Dyn-SP+ cells. When given in a novel environment, amphetamine induced c- fos mRNA in both Dyn-SP+ and preproenkephalin mRNA-containing neurons (Enk+ cells). In this condition, D1R and non-selective NMDAR antagonists dose-dependently decreased c- fos expression in Dyn-SP+ cells, but neither D2R nor NR2B-selective NMDAR antagonists had no effect. Furthermore, amphetamine-evoked c- fos expression in Enk+ cells was most sensitive to DAR and NMDAR antagonism; the lowest dose of every antagonist tested significantly decreased c- fos expression only in these cells. Finally, novelty-stress also induced c- fos expression in both Dyn-SP+ and Enk+ cells, and this was relatively resistant to all but D1R antagonists. We suggest that the mechanism(s) by which amphetamine evokes c- fos expression in the CPu varies depending on the stimulus (amphetamine vs. stress), the striatal cell population engaged (Dyn-SP+ vs. Enk+ cells), and environmental context (home vs. novel cage).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66272/1/j.1471-4159.2003.01815.x.pd

Supported online self-management versus care as usual for symptoms of fatigue, pain and urgency/incontinence in adults with inflammatory bowel disease (IBD-BOOST): study protocol for a randomised controlled trial.

BACKGROUND: Despite being in clinical remission, many people with inflammatory bowel disease (IBD) live with fatigue, chronic abdominal pain and bowel urgency or incontinence that limit their quality of life. We aim to test the effectiveness of an online self-management programme (BOOST), developed using cognitive behavioural principles and a theoretically informed logic model, and delivered with facilitator support. PRIMARY RESEARCH QUESTION: In people with IBD who report symptoms of fatigue, pain or urgency and express a desire for intervention, does a facilitator-supported tailored (to patient needs) online self-management programme for fatigue, pain and faecal urgency/incontinence improve IBD-related quality of life (measured using the UK-IBDQ) and global rating of symptom relief (0-10 scale) compared with care as usual? METHODS: A pragmatic two-arm, parallel group randomised controlled trial (RCT), of a 12-session facilitator-supported online cognitive behavioural self-management programme versus care as usual to manage symptoms of fatigue, pain and faecal urgency/incontinence in IBD. Patients will be recruited through a previous large-scale survey of unselected people with inflammatory bowel disease. The UK Inflammatory Bowel Disease Questionnaire and global rating of symptom relief at 6 months are the co-primary outcomes, with multiple secondary outcomes measured also at 6 and 12 months post randomisation to assess maintenance. The RCT has an embedded pilot study, health economics evaluation and process evaluation. We will randomise 680 patients, 340 in each group. Demographic characteristics and outcome measures will be presented for both study groups at baseline. The UK-IBDQ and global rating of symptom relief at 6 and 12 months post randomisation will be compared between the study groups. DISCUSSION: The BOOST online self-management programme for people with IBD-related symptoms of fatigue, pain and urgency has been designed to be easily scalable and implemented. If it is shown to improve patients' quality of life, this trial will enable clinicians and patients to make informed management decisions. This is the first trial, to our knowledge, focused on multiple symptoms prioritised by both people with IBD and health professionals. TRIAL REGISTRATION: ISRCTN71618461 . Registered on 9 September 2019

Is there a common water-activity limit for the three domains of life?

Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (a w) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650-0.605 a w. Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 a w). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 a w for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 a w for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life