Above and belowground community strategies respond to different global change drivers

Environmental changes alter the diversity and structure of communities. By shifting the range of species traits that will be successful under new conditions, environmental drivers can also dramatically impact ecosystem functioning and resilience. Above and belowground communities jointly regulate whole-ecosystem processes and responses to change, yet they are frequently studied separately. To determine whether these communities respond similarly to environmental changes, we measured taxonomic and trait-based responses of plant and soil microbial communities to four years of experimental warming and nitrogen deposition in a temperate grassland. Plant diversity responded strongly to N addition, whereas soil microbial communities responded primarily to warming, likely via an associated decrease in soil moisture. These above and belowground changes were associated with selection for more resource-conservative plant and microbe growth strategies, which reduced community functional diversity. Functional characteristics of plant and soil microbial communities were weakly correlated (P = 0.07) under control conditions, but not when above or belowground communities were altered by either global change driver. These results highlight the potential for global change drivers operating simultaneously to have asynchronous impacts on above and belowground components of ecosystems. Assessment of a single ecosystem component may therefore greatly underestimate the whole-system impact of global environmental changes

Rfam: updates to the RNA families database

Rfam is a collection of RNA sequence families, represented by multiple sequence alignments and covariance models (CMs). The primary aim of Rfam is to annotate new members of known RNA families on nucleotide sequences, particularly complete genomes, using sensitive BLAST filters in combination with CMs. A minority of families with a very broad taxonomic range (e.g. tRNA and rRNA) provide the majority of the sequence annotations, whilst the majority of Rfam families (e.g. snoRNAs and miRNAs) have a limited taxonomic range and provide a limited number of annotations. Recent improvements to the website, methodologies and data used by Rfam are discussed. Rfam is freely available on the Web at http://rfam.sanger.ac.uk/and http://rfam.janelia.org/

The oxytocin analogue carbetocin prevents emotional impairment and stress-induced reinstatement of opioid-seeking in morphine-abstinent mice.

The main challenge in treating opioid addicts is to maintain abstinence due to the affective consequences associated with withdrawal which may trigger relapse. Emerging evidence suggests a role of the neurohypophysial peptide oxytocin (OT) in the modulation of mood disorders as well as drug addiction. However, its involvement in the emotional consequences of drug abstinence remains unclear. We investigated the effect of 7-day opioid abstinence on the oxytocinergic system and assessed the effect of the OT analogue carbetocin (CBT) on the emotional consequences of opioid abstinence, as well as relapse. Male C57BL/6J mice were treated with a chronic escalating-dose morphine regimen (20-100 mg/kg/day, i.p.). Seven days withdrawal from this administration paradigm induced a decrease of hypothalamic OT levels and a concomitant increase of oxytocin receptor (OTR) binding in the lateral septum and amygdala. Although no physical withdrawal symptoms or alterations in the plasma corticosterone levels were observed after 7 days of abstinence, mice exhibited increased anxiety-like and depressive-like behaviors and impaired sociability. CBT (6.4 mg/kg, i.p.) attenuated the observed negative emotional consequences of opioid withdrawal. Furthermore, in the conditioned place preference paradigm with 10 mg/kg morphine conditioning, CBT (6.4 mg/kg, i.p.) was able to prevent the stress-induced reinstatement to morphine-seeking following extinction. Overall, our results suggest that alterations of the oxytocinergic system contribute to the mechanisms underlying anxiety, depression, and social deficits observed during opioid abstinence. This study also highlights the oxytocinergic system as a target for developing pharmacotherapy for the treatment of emotional impairment associated with abstinence and thereby prevention of relapse

Behavioural activation induced in the rat by substance P infusion into ventral tegmental area: implication of dopaminergic A10 neurones.

The functional role of the putative transmitter substance P (SP) was studied using a behavioural approach. SP infusion into the ventral tegmental area in awake rats elicited an increase in locomotor activity which could be blocked by either infusion of a neuroleptic into the nucleus accumbens septi (NAS) or by 6-hydroxydopamine (6-OHDA) lesions of the ascending dopaminergic A10 neurones. Our results suggest that SP induces its behavioural effects through activation of dopaminergic A10 neurones, and imply that endogenous SP may have an important modulatory role

Interactions between D-ala-met-enkephalin, A10 dopaminergic neurones, and spontaneous behaviour in the rat.

We have investigated the interaction between opioid peptides and dopaminergic A10 (DA-A10) neurones in the ventral tegmental area (VTA). The behavioural consequences of VTA infusion of d-Ala-Met-enkephalinamide (DALA) were analyzed. DALA elicited a dose-dependent increase in locomotor activity measured in photocell cages and the circular corridor. Observations in the open field and in a hole box revealed that DALA-induced behavioural stimulation was characterized by enhancement of locomotion, rearing, and number of hole visits, while grooming time and duration of hole visits were decreased. DALA-induced stimulation was reserved by naloxone, and was completely blocked by 6-OHDA destruction of DA-A10 terminals. d-Amphetamine-induced behavioural activation was potentiated by simultaneous VTA infusion of DALA which indicates that the behavioural response to DALA is dependent on DA-A10 neuronal activity. It is postulated that stimulation of opiate receptors exerts a presynaptic inhibition of an inhibitory input to DA-A10 neurones (eg. GABA or dendritic DA), thus releasing dopaminergic activity. In contrast to the acute effect, the d-amphetamine response was strongly attenuated 4 h, 1 and 6 days after VTA infusion of DALA, and returned to normal only at 14 days. This long-lasting modification may reflect decreased activity of opioid neurones, releasing the inhibition of DA-A10 neurones. Our findings suggest that endogenous opioid peptides may exert a modulatory influence on the dopaminergic mesocorticolimbic system

Effect of injections of 6-OHDA into either nucleus accumbens septi or frontal cortex on spontaneous and drug-induced activity.

The effect of injections of 6-hydroxydopamine (6-OHDA) into either frontal cortex (FCx) or nucleus accumbens (NAS) on spontaneous, amphetamine and apomorphine photocell cage activity was studied. Both lesions groups had significant noradrenaline depletion in frontal cortex but only the FCx group had significant dopamine depletion in frontal cortex. Whereas NAS 6-OHDA rats exhibited enhanced apomorphine- and decreased amphetamine-activity there were no differences in activity of the FCx group. 6-OHDA NAS rats also exhibited spontaneous hypoactivity on the third but not the seventh post-operative day; there were no differences in spontaneous activity on either days in the FCx group. In 1975 Kelly, Seviour and Iversen demonstrated that destruction of forebrain dopaminergic terminals induced with injection sof 6-hydroxydopamine (6-OHDA) into the nucleus accumbens septi (NAS) attenuated the locomotor response to 1.5 mg/kg d-amphetamine without affecting stereotypy seen at 5.0 mg/kg. In addition, these rats exhibited an enhanced locomotor response to the dopamine receptor agonist apomorphine, an effect thought to reflect receptor supersensitivity induced by dopamine denervation (Ungerstedt, 1971). Biochemical assay data revealed that dopamine levels were significantly reduced both in nucleus accumbens septi (NAS) and olfactory tubercle (OT) but not neostriatum; thus it was concluded that amphetamine- and apomorphine-induced locomotor activity is mediated by the mesolimbic dopamine system. Since then it has become clear that the A10 group of dopamine (DA) cells bodies in the ventral tegmental area (VTA), give rise to dopamine fibres which innervate not only NAS and OT, but also frontal cortex (Bjorklund and Lindvall, 1978).(ABSTRACT TRUNCATED AT 250 WORDS