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Capek, M.

Publications and source records attributed to Capek, M..

3 recordsLinked to original sources

Beta2* Nicotinic Receptors Tune Prefrontal Behavior Through Distinct Neuronal Populations

Beta2 subunit-containing nicotinic acetylcholine receptors (beta2*nAChRs) are highly expressed in the prefrontal cortex (PFC) and critically regulate behavioral and cognitive domains that are disrupted in neuropsychiatric disorders. Despite their therapeutic potential, the cell-type- and circuit-specific functions of beta2* nAChRs remain poorly defined, partially due to the lack of selective pharmacological tools. Here, we delineate the cellular expression patterns and behavioral roles of beta2* nAChRs expressed in a general vs. highly specific neuronal populations of the mouse PFC. Using fluorescence in situ hybridization (FISH), we mapped beta2 nicotinic subunit expression across cortical layers and major neuronal classes. We then employed CRISPR-mediated knockdown (KD) to reduce beta2* nAChRs expression selectively in two distinct PFC neuronal populations and, for comparison, in a striatal population. The KD of beta2* nAChRs in a mixed population of excitatory and inhibitory neurons in deep PFC layers resulted in a mild impairment of social and exploratory behaviors. In contrast, KD in a highly selective population of superficial-layer interneurons expressing the serotonin receptor 5HT3a induced a robust hypersocial phenotype, accompanied by changes in exploratory behavior. Notably, KD of beta2* nAChRs in a rare NPY-expressing striatal population slightly affected similar behavioral domains, but in the opposite direction to PFC manipulations. Together, these findings reveal opposing, cell-type- and region-specific contributions of beta2* nAChRs to behavioral regulations, highlighting the necessity of circuit-resolved targeting strategies to improve the precision and efficacy of therapeutic intervention for neuropsychiatric disorders.

neuroscience↗

PRPF8-associated retinitis pigmentosa variant induces human neural retina-autonomous photoreceptor defects

Retinitis pigmentosa (RP) is an inherited retinal disorder characterized by the progressive loss of photoreceptors that currently lacks effective treatment. Here, we investigated the impact of the pathogenic PRPF8-Y2334N variant on neural retina cells in hiPSC-derived retinal organoids. Expression of this variant resulted in photoreceptor defects, including thinning of the outer segment layer. At the molecular level, we observed relatively minor changes in mRNA expression in multiple retinal cells, indicating that neural retina cells are impacted independently of retinal pigment epithelium (RPE). We found splicing alterations in genes associated with neural and retinal diseases, including those involved in intraflagellar transport, suggesting that these genes may represent common targets of splicing factor mutations. We further detected the misexpression of several circular RNAs (circRNAs), which could serve as early biomarkers of splicing defects caused by RP mutations. Together, we present a model of RP that recapitulates photoreceptor degeneration and demonstrates that these defects are independent of RPE erosion.

cell biology↗

A sample preparation procedure enables acquisition of 2-channel super-resolution 3D STED image of an entire oocyte

Super-resolution (SR) microscopy is a cutting-edge method that can provide detailed structural information with high resolution. However, the thickness of the specimen has been a major limitation for SR methods, and larger structures have posed a challenge. To overcome this, the key step is to optimize sample preparation to ensure optical homogeneity and clarity, which can enhance the capabilities of SR methods for the acquisition of thicker structures. Oocytes are the largest cells in the mammalian body and are crucial objects in reproductive biology. They are especially useful for studying membrane proteins. However, oocytes are extremely fragile and sensitive to mechanical manipulation and osmotic shocks, making sample preparation a critical and challenging step. We present an innovative, simple, and sensitive approach to oocyte sample preparation for 3D STED acquisition. This involves alcohol dehydration and mounting into a high refractive index medium. This extended preparation procedure allowed us to successfully obtain a unique 2-channel 3D STED super-resolution image of an entire mouse oocyte. By optimizing sample preparation, we can overcome the limitations of SR methods and obtain high-resolution images of larger structures, such as oocytes, Knowledge of which are important for understanding fundamental biological processes. RESEARCH HIGHLIGHTSO_LIThis study aimed to develop a successful sample preparation protocol for imaging mouse oocytes using 3D STED super-resolution microscopy. C_LIO_LIThe results showed that the oocyte sample was optically homogenous, enhancing the capability of the 3D STED method to capture high-resolution images throughout the full depth of the sample, resulting in highly similar SR images. C_LIO_LIThe 3D STED point spread function (PSF) pattern of the depletion laser was successfully secured throughout the entire volume of the sample, including the top and bottom. C_LIO_LIThis study presents the first-ever full volume 3D image of the mouse oocyte, which was acquired using a 2-channel 3D STED method. C_LI GRAPHICAL ABSTRACTIntroducing an extended sample preparation procedure resulted in an outstanding optical quality sample environment pronounced by high refractive index, high transparency, and minimal spherical aberration. This procedure allowed 3D STED within the entire oocyte. O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

cell biology↗