Prefrontal Norepinephrine Determines Attribution of “High” Motivational Salience

Intense motivational salience attribution is considered to have a major role in the development of different psychopathologies. Numerous brain areas are involved in “normal” motivational salience attribution processes; however, it is not clear whether common or different neural mechanisms also underlie intense motivational salience attribution. To elucidate this a brain area and a neural system had to be envisaged that were involved only in motivational salience attribution to highly salient stimuli. Using intracerebral microdialysis, we found that natural stimuli induced an increase in norepinephrine release in the medial prefrontal cortex of mice proportional to their salience, and that selective prefrontal norepinephrine depletion abolished the increase of norepinephrine release in the medial prefrontal cortex induced by exposure to appetitive (palatable food) or aversive (light) stimuli independently of salience. However, selective norepinephrine depletion in the medial prefrontal cortex impaired the place conditioning induced exclusively by highly salient stimuli, thus indicating that prefrontal noradrenergic transmission determines approach or avoidance responses to both reward- and aversion-related natural stimuli only when the salience of the unconditioned natural stimulus is high enough to induce sustained norepinephrine outflow. This affirms that prefrontal noradrenergic transmission determines motivational salience attribution selectively when intense motivational salience is processed, as in conditions that characterize psychopathological outcomes

Alternative splicing of barley clock genes in response to low temperature:evidence for alternative splicing conservation

Alternative splicing (AS) is a regulated mechanism that generates multiple transcripts from individual genes. It is widespread in eukaryotic genomes and provides an effective way to control gene expression. At low temperatures, AS regulates Arabidopsis clock genes through dynamic changes in the levels of productive mRNAs. We examined AS in barley clock genes to assess whether temperature-dependent AS responses also occur in a monocotyledonous crop species. We identify changes in AS of various barley core clock genes including the barley orthologues of Arabidopsis AtLHY and AtPRR7 which showed the most pronounced AS changes in response to low temperature. The AS events modulate the levels of functional and translatable mRNAs, and potentially protein levels, upon transition to cold. There is some conservation of AS events and/or splicing behaviour of clock genes between Arabidopsis and barley. In addition, novel temperature-dependent AS of the core clock gene HvPPD-H1 (a major determinant of photoperiod response and AtPRR7 orthologue) is conserved in monocots. HvPPD-H1 showed a rapid, temperature-sensitive isoform switch which resulted in changes in abundance of AS variants encoding different protein isoforms. This novel layer of low temperature control of clock gene expression, observed in two very different species, will help our understanding of plant adaptation to different environments and ultimately offer a new range of targets for plant improvement

Art Painting Testing with Terahertz Pulse and Frequency Modulated Continuous Wave

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