Formation of memory assemblies through the DNA-sensing TLR9 pathway.

As hippocampal neurons respond to diverse types of information, a subset assembles into microcircuits representing a memory. Those neurons typically undergo energy-intensive molecular adaptations, occasionally resulting in transient DNA damage. Here we found discrete clusters of excitatory hippocampal CA1 neurons with persistent double-stranded DNA (dsDNA) breaks, nuclear envelope ruptures and perinuclear release of histone and dsDNA fragments hours after learning.

Contrasting neurochemical and behavioral profiles reflects stress coping styles but not stress responsiveness in farmed gilthead seabream (Sparus aurata).

In fish, as well as in other vertebrates, contrasting suites of physiological and behavioral traits, or coping styles, are often shown in response to stressors. However, the magnitude of the response (i.e.

Dietary l-tryptophan leaves a lasting impression on the brain and the stress response.

Comparative models suggest that effects of dietary tryptophan (Trp) on brain serotonin (5-hydroxytryptamine; 5-HT) neurochemistry and stress responsiveness are present throughout the vertebrate lineage. Moreover, hypothalamic 5-HT seems to play a central role in control of the neuroendocrine stress axis in all vertebrates. Still, recent fish studies suggest long-term effects of dietary Trp on stress responsiveness, which are independent of hypothalamic 5-HT.

Effects of acute and chronic stress on telencephalic neurochemistry and gene expression in rainbow trout (Oncorhynchus mykiss).

By filtering relevant sensory inputs and initiating stress responses, the brain is an essential organ in stress coping and adaptation. However, exposure to chronic or repeated stress can lead to allostatic overload, where neuroendocrinal and behavioral reactions to stress become maladaptive. This work examines forebrain mechanisms involved in allostatic processes in teleost fishes.

Molecular phylogeny of Chloropseidae and Irenidae - cryptic species and biogeography.

Chloropseidae (Leafbirds) and Irenidae (Fairy-bluebirds) are colourful Oriental birds, which have been placed as a deep (old) branch in the radiation of passeroid songbirds. We present a densely sampled molecular phylogeny of the two families based on two nuclear introns (GAPDH and ODC) and two mitochondrial genes (ND3 and cyt-b) largely stemming from old museum specimens. Our results show that several subspecies within both Chloropseidae and Irenidae are genetically distinct and separated in the Miocene some 10-11Million years ago (Mya), indicating a substantial underestimation of species numbers within the two families.