Biology subjects

Staras, K.

Publications and source records attributed to Staras, K..

2 recordsLinked to original sources

bioRxiv2018

Poly(ADP-ribose) Polymerase-1 Hyperactivity at DNA Single-Strand Breaks Triggers Seizures and Shortened Lifespan

Defects in DNA single-strand break repair result in cerebellar ataxia which in Xrcc1Nes-Cre mice is promoted by hyperactivity of the DNA strand break sensor protein, Parp1. Here, we show that Parp1 hyperactivity extends beyond the cerebellum in Xrcc1-defective brain, resulting in lethal seizures and shortened lifespan. We demonstrate that aberrant Parp1 activation triggers seizure-like activity in Xrcc1-defective hippocampus ex vivo and aberrant presynaptic calcium signalling in isolated hippocampal neurons in vitro. Moreover, we show that these defects are prevented by Parp1 inhibition and/or deletion. Collectively, these data identify aberrant Parp1 activity at unrepaired DNA breaks as a cell-autonomous source of deregulated presynaptic calcium signalling, and highlight PARP inhibition as a possible therapeutic approach in XRCC1-mutated neurodegenerative disease. SummaryPARP1 activity and presynaptic Ca2+ signalling

neuroscience↗

bioRxiv2018

A central control circuit for encoding perceived food value

Hunger state can substantially alter the perceived value of a stimulus, even to the extent that the same sensory cue can trigger antagonistic behaviors. How the nervous system uses such graded perceptual shifts to select between opposed motor patterns remains enigmatic. Here we challenged food-deprived and satiated Lymnaea to choose between two mutually exclusive behaviors, ingestion or egestion, produced by the same feeding central pattern generator. Decoding the underlying neural circuit reveals that the activity of central dopaminergic interneurons defines hunger state and drives network reconfiguration, biasing satiated animals towards the rejection of stimuli deemed palatable by food-deprived ones. By blocking the action of these neurons, satiated animals can be reconfigured to exhibit a hungry animal phenotype. This centralized mechanism occurs in the complete absence of sensory retuning and generalizes across different sensory modalities, allowing food-deprived animals to increase their perception of food value in a stimulus-independent manner to maximize potential calorific intake.

neuroscience↗