This study investigated the effects of donepezil and a combination of donepezil and mefloquine (THN201) on cognitive function and electroencephalography (EEG) parameters during a scopolamine challenge in healthy participants. Scopolamine, which is known to induce cognitive impairment, was used to model transient cognitive deficits similar to those observed in Alzheimer's disease. The study involved 152 healthy male participants, who were subjected to various cognitive tests and EEG recordings to assess the impact of the treatments on attention and memory processes. The results showed significant temporal effects on cognitive performance and positive component around 300 milliseconds EEG parameters, indicating that scopolamine-induced notable changes in cognitive functions and brain activity. However, this study did not find significant overall group differences or interactions between time and group for most cognitive and EEG measures. The combination of donepezil and mefloquine (THN201) did not show a clear protective or restorative effect against scopolamine-induced impairments, highlighting the role of the cholinergic system in cognitive processes and the potential of EEG parameters as markers for cognitive impairment. This study underscores the complexity of cholinergic modulation in attention and memory, suggesting a need for more targeted approaches in future research. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Astrocytes crucially contribute to synaptic physiology and information processing. One of their key characteristics is to express high levels of connexins (Cxs), the gap junction-forming protein. Among them, Cx30 displays specific properties since it is postnatally expressed and dynamically upregulated by neuronal activity and modulates cognitive processes by shaping synaptic and network activities, as recently shown in knockout mice. However, it remains unknown whether local and selective upregulation of Cx30 in postnatal astrocytes within a physiological range modulates neuronal activities in the hippocampus. We here show in mice that, whereas Cx30 upregulation increases the connectivity of astroglial networks, it decreases spontaneous and evoked synaptic transmission. This effect results from a reduced neuronal excitability and translates into an alteration in the induction of synaptic plasticity and an in vivo impairment in learning processes. Altogether, these results suggest that astroglial networks have a physiologically optimized size to appropriately regulate neuronal functions.

Spreading depolarizations (SDs) are an enigmatic and ubiquitous co-morbidity of neural dysfunction. SDs are propagating waves of local field depolarization and increased extracellular potassium. They increase the metabolic demand on brain tissue, resulting in changes in tissue blood flow, and are associated with adverse neurological consequences including stroke, epilepsy, neurotrauma, and migraine. Their occurrence is associated with poor patient prognosis through mechanisms which are only partially understood. Here we show in vivo that two (structurally dissimilar) drugs, which suppress astroglial gap junctional communication, can acutely suppress SDs. We found that mefloquine hydrochloride (MQH), administered IP, slowed the propagation of the SD potassium waveform and intermittently led to its suppression. The hemodynamic response was similarly delayed and intermittently suppressed. Furthermore, in instances where SD led to transient tissue swelling, MQH reduced observable tissue displacement. Administration of meclofenamic acid (MFA) IP was found to reduce blood flow, both proximal and distal, to the site of SD induction, preceding a large reduction in the amplitude of the SD-associated potassium wave. We introduce a novel image processing scheme for SD wavefront localization under low-contrast imaging conditions permitting full-field wavefront velocity mapping and wavefront parametrization. We found that MQH administration delayed SD wavefront's optical correlates. These two clinically used drugs, both gap junctional blockers found to distinctly suppress SDs, may be of therapeutic benefit in the various brain disorders associated with recurrent SDs.

Generation of relevant and robust models for neurological disorders is of main importance for both target identification and drug discovery. The non-cell autonomous effects of glial cells on neurons have been described in a broad range of neurodegenerative and neurodevelopmental disorders, pointing to neuroglial interactions as novel alternative targets for therapeutics development. Interestingly, the recent breakthrough discovery of human induced pluripotent stem cells (hiPSCs) has opened a new road for studying neurological and neurodevelopmental disorders "in a dish". Here, we provide an overview of the generation and modeling of both neuronal and glial cells from human iPSCs and a brief synthesis of recent work investigating neuroglial interactions using hiPSCs in a pathophysiological context.

Real‐world evidence (RWE) refers to observational data gathered outside the formalism of randomized controlled trials, in real life situations, on marketed drugs. While clinical trials are the gold standards to demonstrate the efficacy and tolerability of a medicinal product, the generalizability of their results to actual use in real‐life is limited by the biases induced by the very nature of clinical trials; indeed, the patients included in the trials may differ from actual users because of their concomitant diseases or treatments, or other factors excluding them from the trials. Clinical researchers and pharmaceutical industries have hence become increasingly interested in expanding and integrating RWE into clinical research, by capitalizing on the exponential growth in access to data from electronic health records, claims databases, electronic devices, software or mobile applications, registries embedded in clinical practice and social media. Meanwhile, applications of RWE may also be used for drug discovery and repurposing, for clinical developments and post‐marketing studies. The aim of this review is to provide our opinion regarding the use of RWE in translational research, including non‐clinical and clinical pharmacology research, at the different step of drugs development use.

Translational methods are needed to monitor the impact of the Alzheimer's disease (AD) and therapies on brain function in animal models and patients. The formation of amyloid plaques was investigated using [18F]florbetapir autoradiography in a mouse model of AD consisting in unilateral intracerebroventricular (i.c.v) injection of amyloid peptide Aβ25-35. Then, an optimized positron emission tomography (PET) imaging protocol using [18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) was performed to estimate brain glucose metabolism: [18F]FDG was injected in awake animals to allow for 40 min brain uptake in freely moving mice. Anesthesia was then induced for 30 min PET acquisition to capture the slow and poorly reversible brain uptake of [18F]FDG. Impact of donepezil (0.25 mg/kg daily, 7 days, orally) on brain function was investigated in AD mice (n = 6 mice/group). Formation of amyloid plaques could not be detected using autoradiography. Compared with sham controls (injection of scramble peptide), significant decrease in [18F]FDG uptake was observed in the AD group in the subcortical volume of the ipsilateral hemisphere. Donepezil restored normal glucose metabolism by selectively increasing glucose metabolism in the affected subcortical volume but not in other brain regions. In mice, [18F]FDG PET imaging can be optimized to monitor impaired brain function associated with i.c.v injection of Aβ25-35, even in the absence of detectable amyloid plaque. This model recapitulates the regional decrease in [18F]FDG uptake observed in AD patients. [18F]FDG PET imaging can be straightforwardly transferred to AD patients and may aid the development of certain therapies designed to restore the altered brain function in AD.

Autophagy is a process leading to the degradation of cellular material, in organelles called lysosomes, to supply energy or generate building blocks for the synthesis of new materials. Over the past decades, its role has been evidenced in several indications, notably in neurodegenerative disorders and orphan diseases called lysosomal storage disorders and its modulation is largely envisioned as a therapeutic avenue to alleviate the symptoms and reverse the clinical courses of these indications. Identifying new chemical classes and drugs is, hence, of huge importance. In this study, we developed automated assays to assess the potential efficacy of chemical compounds on different steps of autophagy, notably its induction through the localization of a largely involved transcription factor, transcription factor EB (TFEB). These assays were then used to screen a collection of 1,520 approved drugs. This study led to the identification of five candidate hits modulating autophagy and TFEB subcellular localization. Our results suggest the repurposing potential of already approved drugs in central nervous system disorders with lysosomal storage impairments.

Attention-Deficit hyperactivity disorder (ADHD) is a central nervous system (CNS) disorder frequently associated with other psychiatric disorders. Pathophysiology processes at stake in ADHD are still under investigation and interestingly neuroimaging data points to modulated brain connectivity in patients. The genetic spontaneously hypertensive rat (SHR) model has been widely used to study pathophysiological underpinnings of ADHD and resting-state brain connectivity using functional magnetic resonance imaging. Here, functional ultrasound imaging, a new technique enabling fast measurement of cerebral blood volume (CBV), was used to further characterize resting-state functional connectivity – at both local and long-range – and visual response in SHR. We demonstrated that response to visual stimulation was increased in SHR in the visual cortex and the superior colliculus. They displayed altered long-range functional connectivity between spatially distinct regions. SHR also displayed modulated local connectivity, with strong increases of regional homogeneity in parts of the motor and visual cortex, along with decreases in the secondary cingulate cortex, the superior colliculus and the pretectal area. As CBV is intricately coupled to cerebral activity, these results suggest an abnormal neural activity in the SHR animal model, consistent with previous clinical studies and demonstrate the potential of functional ultrasound imaging as a translational tool in ADHD.

Background: There is an urgent need to understand and reverse cognitive impairment. The lack of appropriate animal models combined with the limited knowledge of pathophysiological mechanisms makes the development of new cognition-enhancing drugs complex. Scopolamine is a pharmacologic agent which impairs cognition and functional imaging in a wide range of animal species, similarly to what is seen in cognitive impairment in humans. Methods: In this study, using a functional ultrasound (fUS) neuroimaging technique, we monitored the impact of donepezil (DPZ), a potent acetylcholinesterase inhibitor and first-line treatment in patients with mild to moderate Alzheimer's disease, in a scopolamine-induced mouse model. Results: We demonstrated that despite its low impact on the cerebral blood volume (CBV) signal, scopolamine injection produced an overall decrease in functional connectivity between various brain areas. In addition, we revealed that DPZ induced a strong decrease in CBV signal without causing a difference in functional connectivity. Conclusion: Finally, our work highlighted that DPZ counteracted the impact of scopolamine on functional connectivity changes and confirmed the interest of using pharmaco-fUS imaging on cognitive disorders, both in frequent and rare neurological disorders.

Central nervous system disorders remain the leading causes of mortality and morbidity worldwide, affecting more than 1 billion patients. This therapeutic area suffers from high unmet medical needs and the search for innovative approaches to identify therapeutic strategies is urgent in the field. This review will first cover the challenges and opportunities of drug discovery in neurology, and then as well as the new models, such as human model stem cells and animal models under development in the field. In addition, innovative and translational neuroimaging techniques will be discussed, as the use of big data and artificial intelligence to discovery new drugs in neurological and neuropsychiatric disorders.

Clinical pharmacology is the study of drugs in humans, from first-in-human studies to randomized controlled trials (RCTs) and benefit-risk ratio assessment in large populations. The objective of this review is to present the recent innovations that may revolutionize the development of drugs in the future. On behalf of the French Society of Pharmacology and Therapeutics, we provide recommendations to address those future challenges in clinical pharmacology. Whatever the future will be, robust preliminary data on drug mechanism of action and rigorous study design will remain crucial prior to the start of pharmacological studies in human. At the present time, RCTs remain the gold standard to evaluate the efficacy of human drugs, although alternative designs (pragmatic trials, platform trials, etc.) are emerging. Innovations in healthy volunteers' studies and the contribution of new technologies such as artificial intelligence, machine learning, and internet-based trials have the potential to improve drug development. In the field of precision medicine, new disease phenotypes and endotypes will probably help to identify new pharmacological targets, responders to therapies, and patients at risk for drug adverse events. In such a moving landscape, the development of translational research through academic and private partnership, transparent sharing of clinical trial data and enhanced interactions between drug experts, patients, and the general public are priority areas for action.

In vertebrates, intercellular communication is largely mediated by connexins (Cx), a family of structurally related transmembrane proteins that assemble to form hemichannels (HCs) at the plasma membrane. HCs are upregulated in different brain disorders and represent innovative therapeutic targets. Identifying modulators of Cx-based HCs is of great interest to better understand their function and define new treatments. In this study, we developed automated versions of two different cell-based assays to identify new pharmacological modulators of Cx43-HCs. As HCs remain mostly closed under physiological conditions in cell culture, depletion of extracellular Ca2+ was used to increase the probability of opening of HCs. The first assay follows the incorporation of a fluorescent dye, Yo-Pro, by real-time imaging, while the second is based on the quenching of a fluorescent protein, YFPQL, by iodide after iodide uptake. These assays were then used to screen a collection of 2242 approved drugs and compounds under development. This study led to the identification of 11 candidate hits blocking Cx43-HC, active in the two assays, with 5 drugs active on HC but not on gap junction (GJ) activities. To our knowledge, this is the first screening on HC activity and our results suggest the potential of a new use of already approved drugs in central nervous system disorders with HC impairments.

Astrocytes represent the reticular part of the central nervous system; gap junctions formed by connexins Cx43, Cx30- and Cx26 provide for homocellular astrocyte-astrocyte coupling, whereas connexins Cx30, Cx32, Cx43, and Cx47 connect astrocytes and oligodendrocytes. Astroglial networks are anatomically and functionally segregated being homologous to neuronal ensembles. Connexons, gap junctions and hemichannels (unpaired connexons) are affected in various neuropathologies from neuropsychiatric to neurodegenerative diseases. Manipulation of astrocytic connexins modulates the size and outreach of astroglial syncytia thus affecting astroglial homeostatic support. Modulation of astrocytic connexin significantly modifies pharmacological profile of many CNS drugs, which represents an innovative therapeutic approach for CNS disorders; this approach is now actively tested in pre-clinical and clinical studies. Wide combination of connexin modulators with CNS drugs open new promising perspectives for fundamental studies and therapeutic strategies.

Background: Recent advances using functional ultrasound (fUS) imaging have opened new avenues to evaluate brain activity through the regional monitoring of cerebral blood volume (CBV) dynamics. In particular, this technology paves the way for understanding physiological or pathological cerebral processes or exploring the pharmacological profiles of new drugs targeting brain disorders. One of the main difficulties of this technology is the lack of standardized and validated tools, in particular relevant brain atlases, to help improving the accuracy, automation and reproducibility of fUS data analysis. New method: Here, we demonstrate the possibility to use the MRI-validated SIGMA brain atlas in rat to perform fast and precise analysis of CBV changes in numerous functionally relevant regions of interest using fUS imaging. We applied this atlas to a dataset obtained in anesthetized rats evaluating the cerebral effects of atomoxetine, a norepinephrine reuptake inhibitor currently marketed in attention-deficit/hyperactivity-disorder. Results: This approach enabled to show the subregional effects of atomoxetine in the rat with very few interindividual differences in some areas, such as the dentate gyrus. Conclusions: We show the feasibility of inter-individual registration of 2D pharmaco-fUS data and subsequent detailed analysis using the SIGMA atlas.

TFEB is a mammalian transcription factor that binds directly to the CLEAR consensus sequence (5'-GTCACGTGAC-3') present in the regulatory regions of genes inducing autophagosome formation, autophagosome-lysosome fusion, hydrolase enzyme expression, and lysosomal exocytosis. By modulating these activities, TFEB coordinates on-demand control over each cell's degradation pathway. Thus, a nuclear signaling pathway regulates cellular energy metabolism through TFEB. Our growing understanding of the role of TFEB and CLEAR in the promotion of healthy clearance together with in vitro and in vivo preclinical findings in various animal models of disease supports the conclusion that the pharmacological activation of TFEB could clear toxic proteins to treat both rare and common forms of neurodegenerative disease.

Tricyclic antidepressants that inhibit serotonin and noradrenaline reuptake, such as amitriptyline, are among the first-line treatments for neuropathic pain, which is caused by a lesion or disease affecting the somatosensory nervous system. These treatments are, however, partially efficient to alleviate neuropathic pain symptoms, and better treatments are still highly required. Interactions between neurons and glial cells participate in neuropathic pain processes, and importantly, connexins-transmembrane proteins involved in cell-cell communication-contribute to these interactions. In a neuropathic pain model in rats, mefloquine, a connexin inhibitor, has been shown to potentiate the antihyperalgesic effect of amitriptyline, a widely used antidepressant. In this study, we further investigated this improvement of amitriptyline action by mefloquine, using the cuff model of neuropathic pain in mice. We first observed that oral mefloquine co-treatment prolonged the effect of amitriptyline on mechanical hypersensitivity by 12 hours after administration. In addition, we showed that this potentiation was not due to pharmacokinetic interactions between the 2 drugs. Besides, lesional and pharmacological approaches showed that the prolonged effect was induced through noradrenergic descending pathways and the recruitment of alpha(2) adrenoceptors. Another connexin blocker, carbenoxolone, also improved amitriptyline action. Additional in vitro studies suggested that mefloquine may also directly act on serotonin transporters and on adenosine A(1) and A(2A) receptors, but drugs acting on these other targets failed to amplify amitriptyline action. Together, our data indicate that pharmacological blockade of connexins potentiates the therapeutic effect of amitriptyline in neuropathic pain.

Astrocytes were traditionally regarded as cells important to neuronal activity, providing both metabolic and structural supports. Recent evidence suggests that they may also play a crucial role in the control of higher brain functions. In keeping with this hypothesis, it is now well accepted that astrocytes contribute to stress but also react to antidepressant drugs as they express serotonergic transporters and receptors. However, the downstream mechanisms leading to the fine-tuned regulation of mood are still unknown. This chapter pays attention to the role of astrocytes in the regulation of emotional behavior and related serotonergic neurotransmission. In particular, it gives a current state of the clinical and preclinical evidence showing that astrocytes respond to environmental conditions and antidepressant drugs through the release of gliotransmitters and neurotrophic factors which in turn, influence serotonergic tone in discrete brain areas. This state-of-the-art review aims at demonstrating the remarkable potential for novel therapeutic antidepressant strategies targeting these glial cells.

Functional ultrasound (fUS) is a new tool enabling the imaging of brain activity through the regional monitoring of cerebral blood volume (CBV) dynamics. This innovative technique has not yet demonstrated its full potential in pharmacological applications and drug development. In the current proof-of-concept study, the impact of atomoxetine (ATX), a potent norepinephrine reuptake inhibitor and non-stimulant treatment marketed in attention-deficit/hyperactivity-disorder, was evaluated in anesthetized rat using pharmacological functional ultrasound (pharmaco-fUS) at increasing doses (0.3, 1 and 3 mg/kg). Using regions of interest (acute changes of CBV and functional connectivity) or pixel-based (general linear modeling and independent component analysis) analysis, we here demonstrated that ATX consistently displayed a hemodynamic effect in the visual cortex, the dentate gyrus and thalamus, especially visual areas such as lateral posterior thalamic nuclei and lateral geniculate nuclei (LGN). The time profile of ATX effects was dose-dependent, with fastest CBV increases at the highest dose, and longer CBV increases at the intermediate dose. Standardizing the use of pharmaco-fUS could improve our understanding of the mechanism of action of drugs active in the brain and might constitute a new step to move forward in drug development for neurological disorders.

Donepezil (DPZ) is an acetylcholinesterase inhibitor used in Alzheimer's disease to restore cognitive functions but is endowed with limited efficacy. Recent studies pointed out the implication of astroglial networks in cognitive processes, notably via astrocyte connexins (Cxs), proteins involved in gap junction intercellular communications. Hence, we investigated the impact on cognition of pharmacological or genetic modulations of those astrocyte Cxs during DPZ challenge in two rodent models of Alzheimer's disease-like memory deficits. We demonstrated that the Cx modulator mefloquine (MEF) significantly enhanced the procognitive effect of DPZ in both models. In parallel, we determined that MEF potentiated DPZ-induced release of acetylcholine in hippocampus. Finally, local genetic silencing of astrocyte Cxs in the hippocampus was also found to enhance the procognitive effect of DPZ, pointing out the importance of Cx-dependent astrocyte networks in memory processes.

Donepezil is a potent acetylcholinesterase inhibitor, largely used worldwide to alleviate cognitive symptoms in Alzheimer's disease (AD). Beyond the widely described neuronal impact of donepezil, it was recently shown that targeting connexins, the proteins involved in astrocyte network organization, potentiates donepezil efficacy profile using behavioral tests in AD rodent models. We herein present data demonstrating the potential of functional ultrasound imaging to monitor cerebral activity changes after pharmacological challenge in mice. As an example, we showed that although administration of donepezil or mefloquine alone at low dose had only very limited effects on the signal compared to the baseline, their combination produced marked hemodynamic effects in the hippocampus, in line with previously published behavioral data demonstrating a synergic interaction between both drugs. Thus, the present study provides new perspectives, (i) through the use of pharmaco-fUS, a new non-clinical imaging modality, to move forward drug discovery in AD and (ii) by the profiling of two drug treatments on brain dynamics, one used in AD: donepezil, and the other in development: donepezil combined with mefloquine (THN201) as a modulator of astrocyte network.