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Vasoactive intestinal peptide (VIP) interneurons in sensory cortex modulate sensory responses based on global exploratory behavior and arousal state, but their function during non-exploratory, goal-directed behavior is not well understood. In particular, whether VIP cells are activated by sensory cues, reward-seeking actions, or directly by reinforcement is unclear. We trained mice on a Go/NoGo whisker touch detection task that included a delay period and other features designed to separate sensory-evoked, action-related, and reward-related neural activity. Mice had to lick in response to a whisker stimulus to receive a variable-sized reward. Using two-photon calcium imaging, we measured ΔF/F responses of L2/3 VIP neurons in whisker somatosensory cortex (S1) during behavior. In both expert and novice mice, VIP cells were strongly activated by whisker stimuli and goal-directed actions (licking), but not by reinforcement. VIP cells showed somatotopic whisker tuning that was spatially organized relative to anatomical columns in S1, unlike lick-related signals which were spatially widespread. In expert mice, lick-related VIP responses were suppressed, not enhanced, when a reward was delivered, and the amount of suppression increased with reward size. This reward-related suppression was not seen in novice mice, where reward delivery was not yoked to licking. These results indicate that besides arousal and global state variables, VIP cells are activated by local sensory features and goal-directed actions, but not directly by reinforcement. Instead, our results are consistent with a role for VIP cells in encoding the expectation of reward associated with motor actions.

Loss of Lon1 led to stunted plant growth and accumulation of nuclear‐encoded mitochondrial proteins including Lon1 substrates. However, an in‐depth label‐free proteomics quantification of mitochondrial proteins in lon1 revealed that the majority of mitochondrial‐encoded proteins decreased in abundance. Additionally, we found that lon1 mutants contained protein aggregates in the mitochondrial that were enriched in metabolic enzymes, ribosomal subunits and PPR‐containing proteins of the translation apparatus. These mutants exhibited reduced general mitochondrial translation as well as deficiencies in RNA splicing and editing. These findings support the role of Lon1 in maintaining a functional translational apparatus for mitochondrial‐encoded gene translation. Transcriptome analysis of lon1 revealed a mitochondrial unfolded protein response reminiscent of the mitochondrial retrograde signalling dependent on the transcription factor ANAC017. Notably, lon1 mutants exhibited transiently elevated ethylene production, and the shortened hypocotyl observed in lon1 mutants during skotomorphogenesis was partially alleviated by ethylene inhibitors. Furthermore, the short root phenotype was partially ameliorated by introducing a mutation in the ethylene receptor ETR1. Interestingly, the upregulation of only a select few target genes was linked to ETR1‐mediated ethylene signalling. Together this provides multiple steps in the link between loss of Lon1 and signalling responses to restore mitochondrial protein homoeostasis in plants. Summary statement: Plant Lon1 prevents the aggregation of mitochondrial proteins, including metabolic enzymes and components of the translational apparatus such as ribosomal and PPR proteins. Dysfunctional proteins within these aggregates inhibit the translation of mitochondrial‐encoded genes and trigger unfolded protein responses associated with ANAC017. [ABSTRACT FROM AUTHOR]

Based on the viologen ligand 1,1′-bis(3-carboxylatobenzyl)-4,4′-bipyridinium dichloride (H2BcbpyCl2) as the functional subject and two aromatic carboxylic acids (m-H2BDC = 1,3-benzenedicarboxylic acid and H4BTEC = 1,2,4,5-benzenetetracarboxylic acid) as auxiliary ligands, two Zn(II)-based coordination polymers, formulated as [Zn(Bcbpy)0.5(m-BDC)]n (1) and [Zn(Bcbpy)0.5(BTEC)0.5(H2O)]n (2), have been successfully prepared by solvothermal strategies. Compounds 1 and 2 both have a three-dimensional framework. The two compounds demonstrate reversible photochromic properties owing to the formation of viologen radicals via photoinduced electron transfer. In addition, the photomodulated fluorescence and ink-free erasable printing properties were also studied, which enriched the study of the photophysical properties of the crystals. [ABSTRACT FROM AUTHOR]