DNAzyme-Based Lithium-Selective Imaging Reveals Higher Lithium Accumulation in Bipolar Disorder Patient-Derived Neurons

Coupling Nanoscale Precision with Multiscale Imaging: A Multifunctional Near-Infrared Dye for the Brain

Live imaging of primary neural cells is crucial for monitoring neuronal activity, especially multiscale and multifunctional imaging that offers excellent biocompatibility. Multiscale imaging can provide insights into cellular structure and function from the nanoscale to the millimeter scale. Multifunctional imaging can monitor different activities in the brain. However, this remains a challenge because of the lack of dyes with a high signal-to-background ratio, water solubility, and multiscale and multifunctional imaging capabilities. In this study, we present a neural dye with near-infrared (NIR) emissions (>700 nm) that enables ultrafast staining (in less than 1 min) for the imaging of primary neurons. This dye not only enables multiscale neural live-cell imaging from vesicles in neurites, neural membranes, and single neurons to the whole brain but also facilitates multifunctional imaging, such as the monitoring and quantifying of synaptic vesicles and the changes in membrane potential. We also explore the potential of this NIR neural dye for staining brain slices and live brains. The NIR neural dye exhibits superior binding with neural membranes compared to commercial dyes, thereby achieving multiscale and multifunctional brain neuroimaging. In conclusion, our findings introduce a significant breakthrough in neuroimaging dyes by developing a category of small molecular dyes.

Fingerprinting DNAzyme Cross-Reactivity for Pattern-Based Detection of Heavy Metals

Heavy metal contamination in food and water is a major public health concern because heavy metals are toxic in minute amounts. DNAzyme sensors are emerging as a promising tool for rapid onsite detection of heavy metals, which can aid in minimizing exposure. However, DNAzyme activity toward its target metal is not absolute and has cross-reactivity with similar metals, which is a major challenge in the wide-scale application of DNAzyme sensors for environmental monitoring. To address this, we constructed a four DNAzyme array (17E, GR-5, EtNA, and NaA43) and used a pattern-based readout to improve sensor accuracy. We measured cross-reactivity between three metal cofactors (Pb2+, Ca2+, and Na+) and common interferents (Mg2+, Zn2+, Mn2+, UO22+, Li+, K+, and Ag+) and then used t-SNE analysis to identify and quantify the metal ion. We further showed that this method can be used for distinguishing mixtures of metals and detecting Pb2+ in environmental soil samples at micromolar concentrations.

Exploring mood disorders and treatment options using human stem cells

Despite their global prevalence, the mechanisms for mood disorders like bipolar disorder and major depressive disorder remain largely misunderstood. Mood stabilizers and antidepressants, although useful and effective for some, do not have a high responsiveness rate across those with these conditions. One reason for low responsiveness to these drugs is patient heterogeneity, meaning there is diversity in patient characteristics relating to genetics, etiology, and environment affecting treatment. In the past two decades, novel induced pluripotent stem cell (iPSC) research and technology have enabled the use of human-derived brain cells as a new model to study human disease that can help account for patient variance. Human iPSC technology is an emerging tool to better understand the molecular mechanisms of these disorders as well as a platform to test novel treatments and existing pharmaceuticals. This literature review describes the use of iPSC technology to model bipolar and major depressive disorder, common medications used to treat these disorders, and novel patient-derived alternative treatment methods for non-responders stemming from past publications, as well as presenting new data derived from these models.

In-vitro Clinical Diagnostics using RNA-Cleaving DNAzymes

Over the last three decades, significant advancements have been made in the development of biosensors and bioassays that use RNA-cleaving DNAzymes (RCDs) as molecular recognition elements. While early examples of RCDs were primarily responsive to metal ions, the past decade has seen numerous RCDs reported for more clinically relevant targets such as bacteria, cancer cells, small metabolites, and protein biomarkers. Over the past 5 years several RCD-based biosensors have also been evaluated using either spiked biological matrixes or patient samples, including blood, serum, saliva, nasal mucus, sputum, urine, and faeces, which is a critical step toward regulatory approval and commercialization of such sensors. In this review, an overview of the methods used to generate RCDs and the properties of key RCDs that have been utilized for in vitro testing is first provided. Examples of RCD-based assays and sensors that have been used to test either spiked biological samples or patient samples are then presented, highlighting assay performance in different biological matrixes. A summary of current prospects and challenges for development of in vitro diagnostic tests incorporating RCDs and an overview of future directions of the field is also provided.

Dried Blood Spots and Miniaturized Ultrasonic Nebulization Microplasma Optical Emission Spectrometry for Point-of-Care Testing of Blood Lithium

Despite the significant importance of blood lithium (Li) detection in the treatment of bipolar disorder (BD), its point-of-care testing (POCT) remains a great challenge due to tedious sample preparation and the use of large-footprint atomic spectrometers. Herein, a system coupling dried blood spots (DBS) with a point discharge optical emission spectrometer equipped with a miniaturized ultrasonic nebulizer (MUN-μPD-OES) was developed for POCT of blood Li. Three microliters of whole blood were used to prepare a dried blood spot on a piece of filter paper to which 10 μL of eluent (1% (v/v) formic acid and 0.05% (v/v) Triton-X) was added. Subsequently, the paper was placed onto the vibrating steel membrane of the ultrasonic nebulizer and powered on to generate aerosol. The aerosol was directly introduced to the μPD-OES for quantification of Li by monitoring its atomic emission line at 670.8 nm. The proposed method minimized matrix interference caused by high levels of salts and protein. It is worth noting that the MUN suitably matches the needs of DBS sampling and can provide aerosolized introduction of Li into the assembled μPD-OES, thus eliminating all tedious sample preparation and the need for a commercial atomic spectrometer. Calibration response is linear in the therapeutic range and a limit of detection (LOD) of 1.3 μg L-1 is well below the Li minimum therapeutic concentration (2800 μg L-1). Li in mouse blood was successfully detected in real-time using MUN-μPD-OES after intraperitoneal injection of lithium carbonate, confirming that the system holds great potential for POCT of blood Li for patients with BD.

Non-invasive single cell aptasensing in live cells and animals

We report a genetically encoded aptamer biosensor platform for non-invasive measurement of drug distribution in cells and animals. We combined the high specificity of aptamer molecular recognition with the easy-to-detect properties of fluorescent proteins. We generated six encoded aptasensors, showcasing the platform versatility. The biosensors display high sensitivity and specificity for detecting their specific drug target over related analogs. We show dose dependent response of biosensor performance reaching saturating drug uptake levels in individual live cells. We designed our platform for integration into animal genomes; thus, we incorporated aptamer biosensors into zebrafish, an important model vertebrate. The biosensors enabled non-invasive drug biodistribution imaging in whole animals across different timepoints. To our knowledge, this is the first example of an aptamer biosensor-expressing transgenic vertebrate that is carried through generations. As such, our encoded platform addresses the need for non-invasive whole animal biosensing ideal for pharmacokinetic-pharmacodynamic analyses that can be expanded to other organisms and to detect diverse molecules of interest.

Improving the Sensitivity of a Mn(II)-Specific DNAzyme for Cellular Imaging Sensor through Sequence Mutations

Detection of Mn2+ in living cells is important in understanding the roles of Mn2+ in cellular processes and investigating its potential implications in various diseases and disorders. Toward this goal, we have previously selected a Mn2+-specific 11-5 DNAzyme through an in vitro selection method and converted it into a fluorescence sensor for intracellular Mn2+ sensing. Despite the progress, the nucleotides responsible for the activity are unclear, and the performance of the DNAzyme needs to be improved in order for more effective applications in biological systems. To address these issues, we herein report site-specific mutations within the catalytic domain of the selected 11-5 DNAzyme. As a result, we successfully identified a variant DNAzyme, designated as Mn5V, which exhibited a twofold increase in activity compared to the original 11-5 DNAzyme. Importantly, Mn5V DNAzyme maintained its high selectivity for Mn2+ over other competing metal ions. Upon the addition of Mn2+, Mn5V DNAzyme exhibited a higher fluorescence signal within the tumor cells compared to that of the 11-5 DNAzyme. This study therefore provides a better understanding of how the DNAzyme functions and a more sensitive probe for investigating Mn2+ in biological systems.

Chemically Inducible DNAzyme Sensor for Controllable Imaging of Metal Ions

RNA-cleaving DNAzymes have emerged as a promising tool for metal ion detection. Achieving spatiotemporal control over their catalytic activity is essential for understanding the role of metal ions in various biological processes. While photochemical and endogenous stimuli-responsive approaches have shown potential for controlled metal ion imaging using DNAzymes, limitations such as photocytotoxicity, poor tissue penetration, or off-target activation have hindered their application for safe and precise detection of metal ions in vivo. We herein report a chemically inducible DNAzyme in which the catalytic core is modified to contain chemical caging groups at the selected backbone sites through systematic screening. This inducible DNAzyme exhibits minimal leakage of catalytic activity and can be reactivated by small molecule selenocysteines, which effectively remove the caging groups and restore the activity of DNAzyme. Benefiting from these findings, we designed a fluorogenic chemically inducible DNAzyme sensor for controlled imaging of metal ions with tunable activity and high selectivity in live cells and in vivo. This chemically inducible DNAzyme design expands the toolbox for controlling DNAzyme activity and can be easily adapted to detect other metal ions in vivo by changing the DNAzyme module, offering opportunities for precise biomedical diagnosis.

Solar-powered simultaneous highly efficient seawater desalination and highly specific target extraction with smart DNA hydrogels

Obtaining freshwater and important minerals from seawater with solar power facilitates the sustainable development of human society. Hydrogels have demonstrated great solar-powered water evaporation potential, but highly efficient and specific target extraction remains to be expanded. Here, we report the simultaneous highly efficient seawater desalination and specific extraction of uranium with smart DNA hydrogels. The DNA hydrogel greatly promoted the evaporation of water, with the water evaporation rate reached a high level of 3.54 kilograms per square meter per hour (1 kilowatt per square meter). Simultaneously, uranyl-specific DNA hydrogel exhibited a high capture capacity of 5.7 milligrams per gram for uranium from natural seawater due to the rapid ion transport driven by the solar powered interfacial evaporation and the high selectivity (10.4 times over vanadium). With programmable functions and easy-to-use devices, the system is expected to play a role in future seawater treatment.

A Rapid Sputum-based Lateral Flow Assay for Airway Eosinophilia using an RNA-cleaving DNAzyme Selected for Eosinophil Peroxidase

The first protein-binding allosteric RNA-cleaving DNAzyme (RCD) obtained by direct in vitro selection against eosinophil peroxidase (EPX), a validated marker for airway eosinophilia, is described. The RCD has nanomolar affinity for EPX, shows high selectivity against related peroxidases and other eosinophil proteins, and is resistant to degradation by mammalian nucleases. An optimized RCD was used to develop both fluorescence and lateral flow assays, which were evaluated using 38 minimally processed patient sputum samples (23 non-eosinophilic, 15 eosinophilic), producing a clinical sensitivity of 100 % and specificity of 96 %. This RCD-based lateral flow assay should allow for rapid evaluation of airway eosinophilia as an aid for guiding asthma therapy.

A Semisynthetic Bioluminescence Sensor for Ratiometric Imaging of Metal Ions In Vivo Using DNAzymes Conjugated to An Engineered Nano-Luciferase

DNA-based probes have gained significant attention as versatile tools for biochemical analysis, benefiting from their programmability and biocompatibility. However, most existing DNA-based probes rely on fluorescence as the signal output, which can be problematic due to issues like autofluorescence and scattering when applied in complex biological materials such as living cells or tissues. Herein, we report the development of bioluminescent nucleic acid (bioLUNA) sensors that offer laser excitation-independent and ratiometric imaging of the target in vivo. The system is based on computational modelling and mutagenesis investigations of a genetic fusion between circular permutated Nano-luciferase (NLuc) and HaloTag, enabling the conjugation of the protein with a DNAzyme. In the presence of Zn2+ , the DNAzyme sensor releases the fluorophore-labelled strand, leading to a reduction in bioluminescent resonance energy transfer (BRET) between the luciferase and fluorophore. Consequently, this process induces ratiometric changes in the bioluminescent signal. We demonstrated that this bioLUNA sensor enabled imaging of both exogenous Zn2+ in vivo and endogenous Zn2+ efflux in normal epithelial prostate and prostate tumors. This work expands the DNAzyme sensors to using bioluminescence and thus has enriched the toolbox of nucleic acid sensors for a broad range of biomedical applications.

Ratiometric Detection of Zn2+ Using DNAzyme-Based Bioluminescence Resonance Energy Transfer Sensors

While fluorescent sensors have been developed for monitoring metal ions in health and diseases, they are limited by the requirement of an excitation light source that can lead to photobleaching and a high autofluorescence background. To address these issues, bioluminescence resonance energy transfer (BRET)-based protein or small molecule sensors have been developed; however, most of them are not highly selective nor generalizable to different metal ions. Taking advantage of the high selectivity and generalizability of DNAzymes, we report herein DNAzyme-based ratiometric sensors for Zn2+ based on BRET. The 8-17 DNAzyme was labeled with luciferase and Cy3. The proximity between luciferase and Cy3 permiQed BRET when coelenterazine, the substrate for luciferase, was introduced. Adding samples containing Zn2+ resulted in a cleavage of the substrate strand, causing dehybridization of the DNAzyme construct, thus increasing the distance between Cy3 and luciferase and changing the BRET signals. Using these sensors, we detected Zn2+ in serum samples and achieved Zn2+ detection with a smartphone camera. Moreover, since the BRET pair is not the component that determines the selectivity of the sensors, this sensing platform has the potential to be adapted for the detection of other metal ions with other metal-dependent DNAzymes.

Development of 8-17 XNAzymes that are functional in cells

DNA enzymes (DNAzymes), which cleave target RNA with high specificity, have been widely investigated as potential oligonucleotide-based therapeutics. Recently, xeno-nucleic acid (XNA)-modified DNAzymes (XNAzymes), exhibiting cleavage activity in cultured cells, have been developed. However, a versatile approach to modify XNAzymes that function in cells has not yet been established. Here, we report an X-ray crystal structure-based approach to modify 8-17 DNAzymes; this approach enables us to effectively locate suitable XNAs to modify. Our approach, combined with a modification strategy used in designing antisense oligonucleotides, rationally designed 8-17 XNAzyme ("X8-17") that achieved high potency in terms of RNA cleavage and biostability against nucleases. X8-17, modified with 2'-O-methyl RNA, locked nucleic acid and phosphorothioate, successfully induced endogenous MALAT-1 and SRB1 RNA knockdown in cells. This approach may help in developing XNAzyme-based novel therapeutic agents.

Transcriptional and functional effects of lithium in bipolar disorder iPSC-derived cortical spheroids

Lithium (Li) is recommended for long-term treatment of bipolar disorder (BD). However, its mechanism of action is still poorly understood. Induced pluripotent stem cell (iPSC)-derived brain organoids have emerged as a powerful tool for modeling BD-related disease mechanisms. We studied the effects of 1 mM Li treatment for 1 month in iPSC-derived human cortical spheroids (hCS) from 10 healthy controls (CTRL) and 11 BD patients (6 Li-responders, Li-R, and 5 Li non-treated, Li-N). At day 180 of differentiation, BD hCS showed smaller size, reduced proportion of neurons, decreased neuronal excitability and reduced neural network activity compared to CTRL hCS. Li rescued excitability of BD hCS neurons by exerting an opposite effect in the two diagnostic groups, increasing excitability in BD hCS and decreasing it in CTRL hCS. We identified 132 Li-associated differentially expressed genes (DEGs), which were overrepresented in sodium ion homeostasis and kidney-related pathways. Moreover, Li regulated secretion of pro-inflammatory cytokines and increased mitochondrial reserve capacity in BD hCS. Through long-term Li treatment of a human 3D brain model, this study partly elucidates the functional and transcriptional mechanisms underlying the clinical effects of Li, such as rescue of neuronal excitability and neuroprotection. Our results also underscore the substantial influence of treatment duration in Li studies. Lastly, this study illustrates the potential of patient iPSC-derived 3D brain models for precision medicine in psychiatry.

A Highly Selective Mn(II)-Specific DNAzyme and Its Application in Intracellular Sensing

Manganese is an essential trace element in the human body that acts as a cofactor in many enzymes and metabolisms. It is important to develop methods to detect Mn²⁺ in living cells. While fluorescent sensors have been very effective in detecting other metal ions, Mn²⁺-specific fluorescent sensors are rarely reported due to nonspecific fluorescence quenching by the paramagnetism of Mn²⁺ and poor selectivity against other metal ions such as Ca²⁺ and Mg²⁺. To address these issues, we herein report in vitro selection of an RNA-cleaving DNAzyme with exceptionally high selectivity for Mn²⁺. Through converting it into a fluorescent sensor using a catalytic beacon approach, Mn²⁺ sensing in immune cells and tumor cells has been achieved. The sensor is also used to monitor degradation of manganese-based nanomaterials such as MnOx in tumor cells. Therefore, this work provides an excellent tool to detect Mn²⁺ in biological systems and monitor the Mn²⁺-involved immune response and antitumor therapy.

Simultaneous Fe2+/Fe3+ imaging shows Fe3+ over Fe2+ enrichment in Alzheimer's disease mouse brain

Visualizing redox-active metal ions, such as Fe²⁺ and Fe³⁺ ions, are essential for understanding their roles in biological processes and human diseases. Despite the development of imaging probes and techniques, imaging both Fe²⁺ and Fe³⁺ simultaneously in living cells with high selectivity and sensitivity has not been reported. Here, we selected and developed DNAzyme-based fluorescent turn-on sensors that are selective for either Fe²⁺ or Fe³⁺, revealing a decreased Fe³⁺/Fe²⁺ ratio during ferroptosis and an increased Fe³⁺/Fe²⁺ ratio in Alzheimer's disease mouse brain. The elevated Fe³⁺/Fe²⁺ ratio was mainly observed in amyloid plaque regions, suggesting a correlation between amyloid plaques and the accumulation of Fe³⁺ and/or conversion of Fe²⁺ to Fe³⁺. Our sensors can provide deep insights into the biological roles of labile iron redox cycling.

Olfactory Receptors as an Emerging Chemical Sensing Scaffold

Chemical biosensors are an increasingly ubiquitous part of our lives. Beyond enzyme-coupled assays, recent synthetic biology advances now allow us to hijack more complex biosensing systems to respond to difficult to detect analytes, such as chemical small molecules. Here, we briefly overview recent advances in the biosensing of small molecules, including nucleic acid aptamers, allosteric transcription factors, and two-component systems. We then look more closely at a recently developed chemical sensing system, G protein-coupled receptor (GPCR)-based sensors. Finally, we consider the chemical sensing capabilities of the largest GPCR subfamily, olfactory receptors (ORs). We examine ORs' role in nature, their potential as a biomedical target, and their ability to detect compounds not amenable for detection using other biological scaffolds. We conclude by evaluating the current challenges, opportunities, and future applications of GPCR- and OR-based sensors.

Lithium produces bi-directionally regulation of mood disturbance, acts synergistically with anti-depressive/-manic agents, and did not deteriorate the cognitive impairment in murine model of bipolar disorder

Lithium (Li) is a well-established mood disorder treatment and may be neuroprotective. Bi-directional regulation (i.e. affecting manic symptoms and depressive symptoms) by Li has not been demonstrated. This study explored: (1) bidirectional regulation by Li in murine models of depression, mania, and bipolar disorder (BP); and (2) potential Li synergism with antidepressant/anti-mania agents. The chronic unpredictable mild stress (CUMS) and ketamine-induced mania (KM) models were used. These methods were used in series to produce a BP model. In vivo two-photon imaging was used to visualize Ca²⁺ activity in the dorsolateral prefrontal cortex. Depressiveness, mania, and cognitive function were assessed with the forced swim task (FST), open field activity (OFA) task, and novel object recognition task, respectively. In CUMS mice, Ca²⁺ activity was increased strongly by Li and weakly by lamotrigine (LTG) or valproate (VPA), and LTG co-administration reduced Li and VPA monotherapy effects; depressive immobility in the FST was attenuated by Li or LTG, and attenuated more strongly by LTG-VPA or LTG-Li; novel object exploration was increased strongly by Li and weakly by LTG-Li, and reduced by LTG, VPA, or LTG-VPA. In KM mice, Li or VPA attenuated OFA mania symptoms and normalized Ca²⁺ activity partially; Li improved cognitive function while VPA exacerbated the KM alteration. These patterns were replicated in the respective BP model phases. Lithium had bi-directional, albeit weak, mood regulation effects and a cognitive supporting effect. Li co-administration with antidepressant/-manic agents enhanced mood-regulatory efficacy while attenuating their cognitive-impairing effects.

2-Aminopurine Fluorescence Spectroscopy for Probing a Glucose Binding Aptamer

Glucose is the most important analyte for biosensors. Recently a DNA aptamer was reported allowing binding-based detection. However, due to a relatively weak binding affinity, it is difficult to perform binding assays to understand the property of this aptamer. In this work, we replaced the only adenine base in the aptamer binding pocket with a 2-aminopurine (2AP) and used fluorescence spectroscopy to study glucose binding. In the selection buffer, glucose increased the 2AP fluorescence with a Kd of 15.0 mM glucose, which was comparable with the 10 mM Kd previously reported using the strand displacement assay. The binding required two Na+ ions or one Mg2+ that cannot be replaced by Li+ or K+. The binding was weaker at higher temperature and its van't Hoff plot indicated enthalpy-driven binding. While monosaccharides failed to achieve saturated binding even at high concentrations, two glucose-containing disaccharides, namely trehalose and sucrose, reached a similar fluorescence level as glucose although with over 10-fold higher Kd's. Detection limits in both the selection buffer (0.9 mM) and in artificial interstitial fluids (6.0 mM) were measured.

Recent Advances on DNAzyme-Based Sensing

DNAzymes are functional nucleic acid with catalytic activity. Owing to the high sensitivity, excellent programmability, and flexible obtainment through in vitro selection, RNA-cleaving DNAzymes have attracted increasing interest in developing DNAzyme-based sensors. In this review, we summarize the recent advances on DNAzyme-based sensing applications. We initially conclude two general strategies to expand the library of DNAzymes, in vitro selection to discover new DNAzymes towards different targets of interest and chemical modifications to endue the existing DNAzymes with new function or properties. We then discuss the recent applications of DNAzyme-based sensors for the detection of a variety of important biomolecules both in vitro and in vivo . Finally, perspectives on the challenges and future directions in the development of DNAzyme-based sensors are provided.

Nucleic Acids and Their Analogues for Biomedical Applications

Nucleic acids are emerging as powerful and functional biomaterials due to their molecular recognition ability, programmability, and ease of synthesis and chemical modification. Various types of nucleic acids have been used as gene regulation tools or therapeutic agents for the treatment of human diseases with genetic disorders. Nucleic acids can also be used to develop sensing platforms for detecting ions, small molecules, proteins, and cells. Their performance can be improved through integration with other organic or inorganic nanomaterials. To further enhance their biological properties, various chemically modified nucleic acid analogues can be generated by modifying their phosphodiester backbone, sugar moiety, nucleobase, or combined sites. Alternatively, using nucleic acids as building blocks for self-assembly of highly ordered nanostructures would enhance their biological stability and cellular uptake efficiency. In this review, we will focus on the development and biomedical applications of structural and functional natural nucleic acids, as well as the chemically modified nucleic acid analogues over the past ten years. The recent progress in the development of functional nanomaterials based on self-assembled DNA-based platforms for gene regulation, biosensing, drug delivery, and therapy will also be presented. We will then summarize with a discussion on the advanced development of nucleic acid research, highlight some of the challenges faced and propose suggestions for further improvement.

Lithium bidirectionally regulates depression- and mania-related brain functional alterations without worsening cognitive function in patients with bipolar disorder

Lithium monotherapy has been proposed to have antidepressant and antimanic effects in patients with bipolar disorder (BP). However, so far, it is lack of evidence to support this proposition. The main aim of this study was to test the hypothesis that lithium bidirectionally regulates depression- and mania-related brain functional abnormalities in patients with BP. We also assessed the effects of lithium, alone and in combination with other pharmacological treatments, on patients' cognitive performance. We enrolled 149 drug-naïve patients with BP; 99 patients experiencing first depressive episodes were allocated randomly to four treatment groups [lithium (DP/Li), lithium with lamotrigine (LTG; DP/Li+LTG), LTG (DP/LTG), and valproate (VPA) with LTG (DP/VPA+LTG)], and 50 experiencing first hypo-manic episodes were allocated to two treatment groups (MA/Li and MA/VPA). For comparative analysis, 60 age-matched healthy individuals were also recruited. Whole-brain global and regional resting-state cerebral blood flow (rs-CBF) and cognitive alterations were examined before and after 12-week treatment. We have the following findings: DP/Li+LTG, and to a lesser extent DP/Li, alleviated the depression-related reduction in rs-CBF. MA/VPA and MA/Li reversed the mania-related elevation of rs-CBF completely and partially, respectively. Lithium alone improved cognitive performance during depressive and manic episodes; other tested treatments have no such effect or worsened cognitive ability. Our results showed that lithium bidirectionally regulates depression- and mania-associated brain functional abnormalities in patients with BP. Lithium monotherapy has a better antimanic effect than VPA, is superior to other tested treatments in improving cognition during the course of BP, and has satisfactory antidepressant effects in patients with BP.