Parkinson's disease (PD) is a movement disorder caused by the loss of dopaminergic innervation, particularly to the striatum. PD patients often exhibit sensory impairments, yet the underlying network mechanisms are unknown. Here we examined how dopamine (DA) depletion affects sensory processing in the mouse striatum. We used the optopatcher for online identification of direct and indirect pathway projection neurons (MSNs) during in vivo whole-cell recordings. In control mice, MSNs encoded the laterality of sensory inputs with larger and earlier responses to contralateral than ipsilateral whisker deflection. This laterality coding was lost in DA-depleted mice due to adaptive changes in the intrinsic and synaptic properties, mainly, of direct pathway MSNs. L-DOPA treatment restored laterality coding by increasing the separation between ipsilateral and contralateral responses. Our results show that DA depletion impairs bilateral tactile acuity in a pathway-dependent manner, thus providing unexpected insights into the network mechanisms underlying sensory deficits in PD. VIDEO ABSTRACT.

The dorsolateral striatum (DLS) receives excitatory inputs from both sensory and motor cortical regions. In the neocortex, sensory responses are affected by motor activity, however, it is not known whether such sensorimotor interactions occur in the striatum and how they are shaped by dopamine. To determine the impact of motor activity on striatal sensory processing, we performed in vivo whole-cell recordings in the DLS of awake mice during the presentation of tactile stimuli. Striatal medium spiny neurons (MSNs) were activated by both whisker stimulation and spontaneous whisking, however, their responses to whisker deflection during ongoing whisking were attenuated. Dopamine depletion reduced the representation of whisking in direct-pathway MSNs, but not in those of the indirect-pathway. Furthermore, dopamine depletion impaired the discrimination between ipsilateral and contralateral sensory stimulation in both direct and indirect pathway MSNs. Our results show that whisking affects sensory responses in DLS and that striatal representation of both processes is dopamine- and cell type-dependent.

Striatal cholinergic interneurons (CINs) can drive local dopamine release via nicotinic acetylcholine receptors (nAChRs) expressed on dopaminergic axons, but their role in modulating serotonin (5-HT) signaling is poorly understood. Here, we show that synchronous activation of CINs directly triggers local 5-HT release in the dorsal striatum via nAChRs expressed on serotonergic axons. This CIN-5-HT coupling is not detectable in the ventral striatum, despite its substantially denser serotonergic innervation. The nAChR-dependent release not only increases 5-HT levels in the dorsal striatum, but also expands the spatial footprint of serotonergic signaling. In Sapap3 mice, a model of obsessive-compulsive disorder (OCD)-like behavior, this mechanism is exaggerated due to a hypercholinergic state, selectively amplifying the nAChR-dependent component of monoamine release. These findings demonstrate a regionally confined form of acetylcholine-5-HT crosstalk in the striatum and identify CINs as regulators of 5-HT dynamics in both healthy and pathological states.

Recent advances in the field of Voltage Imaging, with a special focus on new constructs and novel implementations.

Work related to place tuning, spatial navigation, orientation and direction. Mainly includes articles on connectivity in the hippocampus, retrosplenial cortex, and related areas.

Basal Ganglia Advances is a collection highlighting research on the structure, function, and disorders of the basal ganglia. It features studies spanning neuroscience, clinical insights, and computational models, serving as a hub for advances in movement, cognition, and behavior.

Advances in optical techniques and two-photon (2P) sensitive genetic voltage indicators (GEVIs) enabled in-depth voltage imaging at single-spike and single-cell resolution. These results were achieved using ASAP-type sensors, while rhodopsin-based GEVIs were mainly used with one-photon (1P) illumination. Here, we demonstrate compatibility of rhodopsin-based GEVIs with 2P illumination. We rationally engineer a fully genetically encoded, rhodopsin-based GEVI, just another voltage indicating sensor (Jarvis), and demonstrate its utility under 1P and 2P illumination. We further show 2P usability of the fluorescence resonance energy transfer (FRET)-opsin GEVIs pAce and Voltron2. Comparing 2P scanless with fast 2P scanning illumination revealed that responses are resolved with both approaches, but FRET-opsin GEVIs show improved signal-to-noise ratio (SNR) with low irradiance, inherent to scanless illumination. Utilizing Jarvis and pAce, we establish high-SNR action potential detection at kilohertz imaging rates in mouse hippocampal slices, zebrafish larvae, and the cortex of awake mice, demonstrating high-contrast action potential detection under 2P illumination with rhodopsin-based GEVIs in vitro and in vivo.

As the largest subunit of RNA polymerase II, POLR2A plays an irreplaceable role in gene expression, with the regulation of its own expression and physiological function having attracted widespread attention. Here we report POLR2A as a critical guardian against cellular senescence. A significant decline in POLR2A expression was observed in senescent cells and certain tissues of aging mice. Whereas its depletion dramatically induced cellular senescence, conversely, activating endogenous POLR2A expression in senescent cells using CRISPRa technology alleviated the senescent phenotype. We further demonstrated that POLR2A-induced senescence is p53-dependent, as evidenced by the activation of the p53/p21 pathway upon POLR2A knockdown and the rescue of the senescence phenotype following co-depletion of POLR2A and p53. Bioinformatic analysis on RNA-seq data from POLR2A depletion and replicative senescent cells led to the identification of MDM4 as the key mediator of p53 upregulation following POLR2A knockdown. Most intriguingly, immunoprecipitation assay further revealed that the E3 ligase LMO7 was recruited to POLR2A to promote the ubiquitination and proteasomal degradation of POLR2A under cellular senescence. Depletion of LMO7 abolished the ubiquitination and reduction of POLR2A in H₂O₂-induced senescent cells. Taken together, we concluded that the LMO7-induced POLR2A degradation drived cellular senescence through the MDM4/p53/p21 axis.

Gemcitabine is a cornerstone chemotherapeutic for pancreatic ductal adenocarcinoma (PDAC); however, the frequent development of resistance compromises its efficacy and poses a significant challenge to patient prognosis. Here, we report that nuclear pore protein NUP93 is upregulated in PDAC and correlates with poor patient survival. Functional studies demonstrated that NUP93 promotes PDAC cell proliferation and confers gemcitabine resistance by enhancing DNA damage repair. Mechanistically, NUP93 interacts with the transcription factor SOX2 by recognizing its nuclear localization sequence and facilitates its nuclear import. Nuclear SOX2 transcriptionally activates the key stress granule component G3BP1 by directly binding to its promoter. Subsequently, G3BP1 stabilizes the mRNA of RAD51, a crucial homologous recombination repair factor, thereby promoting DNA damage repair and gemcitabine resistance. In vivo, disruption of the NUP93/SOX2/G3BP1 axis suppressed tumor growth and synergized with gemcitabine. Our findings unveil the novel NUP93-SOX2-G3BP1 signaling axis as a critical driver of gemcitabine resistance in PDAC, presenting a promising therapeutic target for overcoming chemoresistance.