Our results suggest multiplexed encoding of bottom-up acoustic and top-down task-related signals at single AC neurons. This mechanism preserves a stable representation of the acoustic environment despite strong non-acoustic modulations. “
“Because arginase and nitric oxide (NO) synthases (NOS) compete to degrade l-arginine, arginase plays a crucial role in the modulation of NO production. Moreover, the arginase 1 isoform is a marker of M2

phenotype macrophages that play a key role in tissue remodeling and resolution of inflammation. While NO has been extensively investigated in ischemic stroke, the effect of stroke on the arginase pathway is unknown. The present study focuses on arginase expression/activity and localization before and after (1, 8, 15 and 30 days) the photothrombotic ischemic stroke model. This model results in a cortical lesion

that reaches maximal volume at day 1 post-stroke see more and then decreases as a result of astrocytic scar formation. Before stroke, arginase 1 and 2 expressions were restricted to neurons. Stroke resulted in up-regulation of arginase 1 and increased arginase activity in the region centered on the lesion where inflammatory cells are present. These changes were associated with an early and long-lasting arginase 1 up-regulation in activated macrophages and astrocytes and a delayed arginase 1 down-regulation in neurons at the vicinity of the lesion. A linear positive correlation was observed between expressions of arginase 1 and glial fibrillary acidic protein as a marker of activated histone deacetylase activity astrocytes. Moreover, the pattern of arginase 1 and brain-derived neurotrophic factor (BDNF) expressions in activated astrocytes was similar. Unlike arginase 1, arginase 2 expression was not changed Dichloromethane dehalogenase by stroke. In conclusion, increased arginase 1 expression is not restricted to macrophages in inflammation elicited by stroke but also occurs in activated astrocytes where it may contribute to neuroplasticity through the control of BDNF production. “
“The mammalian olfactory cortex is commonly considered critical for

odor information processing and perception. It is becoming increasingly apparent, however, that the olfactory cortex receives input from multiple sensory channels. Previous work from our group demonstrated the presence of auditory sensory convergence within one olfactory cortical structure, the olfactory tubercle (OT). Interestingly, anatomical evidence for auditory input into the neighboring olfactory piriform cortex (PCX) posits the possibility that auditory sensory input is a distributed property of the olfactory cortex. To address this question, we performed in vivo extracellular recordings from the OT and PCX of anesthetized mice and measured modulations in unit firing in the presence of tones. In support for auditory sensory input being a distributed feature of the olfactory cortex, we found that 29% of units sampled within the PCX display tone-evoked responses.