IntelliCage: the development and perspectives of a mouse- and user-friendly automated behavioral test system

Human MAPT knockin mouse models of frontotemporal dementia for the neurodegenerative research community

Existing models of frontotemporal dementia (FTD) may not fully recapitulate the pathophysiology of the disease. To generate more pathophysiologically relevant FTD models, we engineered MAPT knockin mouse lines carrying triple mutations, among which the MAPTP301S;Int10+3;S320F line exhibited robust tau pathology starting before 6 months of age. Severe tau accumulation was predominantly observed in the thalamus, hypothalamus, and amygdala with milder involvement of the cortex and hippocampus, leading to synaptic loss, brain atrophy, and FTD-like behavioral abnormalities. Crossbreeding MAPTP301S;Int10+3;S320F mice with App knockin, AppNL-G-F, mice markedly enhanced tau pathology in the cortex and hippocampus, highlighting the interplay between β-amyloid and tau. These findings establish the mutant mice as valuable models for investigating the mechanisms underlying FTD and other tauopathies, providing a relevant platform for in vivo drug screening.

Mechanistic insights into Quetiapine's Protective effects on cognitive function and synaptic plasticity in epileptic rats

The study aimed to examine the effects of Quetiapine, an atypical antipsychotic medication with purported neuroprotective qualities, on cognitive function and synaptic plasticity in epileptic rats. This investigation also sought to elucidate the mechanisms by which quetiapine influences the activity of the cyclic adenylate response element binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling pathway and metallomatrix proteinase-9 (MMP9) expression in the context of epilepsy. The epileptic model was induced in rats through the administration of pilocarpine, with normal rats serving as the control group. Within the epilepsy group, two subgroups were established: one receiving normal saline and the other receiving quetiapine. Behavioral assays were utilized to assess learning, memory, and spatial exploration abilities. Furthermore, Western blot analysis, immunohistochemistry (IHC), and immunofluorescence (IF) staining were employed to evaluate the activity of the CREB/BDNF pathway, expression of MMP9 protein, and levels of synaptic plasticity-related proteins. Our study revealed that Quetiapine administration led to a notable enhancement in learning and memory in epileptic rats, as indicated by heightened drinking durations and visitation rates in behavioral assessments. Furthermore, Quetiapine upregulated the expression of pro-BDNF, m-BDNF, p-CREB, and CREB within the hippocampus, along with elevating mRNA levels of BDNF and CREB. Additionally, Quetiapine suppressed MMP-9 expression and promoted synaptic plasticity by augmenting SYN and PSD-95 expression levels in the hippocampus. Therefore, Quetiapine improved cognitive functions such as learning, memory, and spatial exploration in epileptic rats. Moreover, Quetiapine activated the CREB/BDNF signaling pathway, suppressed MMP-9 expression, and promoted synaptic plasticity.

Next-Generation Cognitive-Behavioral Therapy for Depression: Integrating Digital Tools, Teletherapy, and Personalization for Enhanced Mental Health Outcomes

Background and Objectives: This systematic review aims to present the latest developments in next-generation CBT interventions of digital support tools, teletherapies, and personalized treatment modules in enhancing accessibility, improving treatment adherence, and optimizing therapeutic outcomes for depression. Materials and Methods: This review analyzed 81 PRISMA-guided studies on the efficacy, feasibility, and applicability of NG-CBT approaches. Other important innovations include web-based interventions, AI-operated chatbots, and teletherapy platforms, each of which serves as a critical challenge in delivering mental health care. Key messages have emerged regarding technological readiness, patient engagement, and the changing role of therapists within the digital context of care. Results: Findings indicate that NG-CBT interventions improve treatment accessibility and engagement while maintaining clinical effectiveness. Personalized digital tools enhance adherence, and teletherapy platforms provide scalable and cost-effective alternatives to traditional therapy. Conclusions: Such developments promise great avenues for decreasing the global burden of depression and enhancing the quality of life through novel, accessible, and high-quality therapeutic approaches.

The first rodent behavioral study (1822) and the diffusion of human-bred albino rats and mice in the 19th century

Rodents, in particular rats and mice, are currently the most widely employed animal models in psychology and behavioral neuroscience. Nevertheless, an interesting historical question is: when was the first rodent behavioral study performed and by whom? The current article presents the first rodent behavioral study in the history of science: a case of interspecies social bonding between a rat and a dog, observed in 1822 by the British chemist Samuel Moss (1794-1868) and subsequently described by the same in a scientific article in 1836. In the present article, after a biographical sketch of Samuel Moss, I examine in detail the notable case of interspecies bonding observed by Moss. This case is notable under several points of view. First, Moss's rat was an albino, a variety which at that time was extremely rare. Moreover, at that time, in the Western world rats were mostly seen as pest animals or baits for rat-catching sports, and were not kept as pets. The color of the rat played a key role in its fate, being the reason for which it was originally brought to Moss and for which Moss decided to keep it under his care. Third, the relationship that arose between the rat and the dog is even more surprising if we consider that the dog was a trained rat-catcher. Importantly, this rat-dog bonding case, which showcased the tameness of Moss's albino rat in both lay and scientific publications, represented the first popularization of the docility of albino rats. After having outlined Moss's case, considering the importance of albino rats in our current society, both in scientific research (where the albino rat has become the prototype of the laboratory rat) and as pets, I provide an historical contextualization regarding albino rodents, starting from the 17th century, and I then trace the history of the post-Moss diffusion of human-bred albino rats and mice in the 19th century.

Time Perception Test in IntelliCage System for Preclinical Study: Linking Depression and Serotonergic Modulation

Background/Objectives:: The link between serotonergic modulation and depression is under debate; however, serotonin reuptake inhibitors (SRIs) are still the first-choice medicine in this condition. Disturbances in time perception are also reported in depression with one of the behavioral schedules used to study interval timing, differential-reinforcement-learning-of-low-rate, having been shown to have high predictive validity for an antidepressant effect. Here, we introduce an IntelliCage research protocol of an interval bisection task that allows more ecologically valid and less time-consuming rodent examination and provides an example of its use to confirm the previously reported acute effect of an SRI, clomipramine, on interval timing (increase in bisection point, D50). Methods: Wistar male rats (n = 25, five groups of 5-8) were trained in the IntelliCage to discriminate between short (1 s) and long (4 s) LED light stimuli by nose poking at the corresponding (left/right) side of the IntelliCage chamber to obtain a drink. When 80% of correct responses were reached, the intermediate durations of 1.7, 2.5, and 3.3 s were introduced. The number of left/right choices for each stimulus and interval timing parameters (bisection point, D50, and timing precision), derived from them, were compared after saline and clomipramine (7 mg/kg, i.p) intraperitoneal administration. Results: Rats successfully learned the task within about a week of training. The slightly increased D50 after clomipramine confirmed previous studies. Conclusions: The introduced protocol has potential to be applicable to preclinical research on depression and potentially other psychopathology, where time perception can be disturbed.

Environmental enrichment: a systematic review on the effect of a changing spatial complexity on hippocampal neurogenesis and plasticity in rodents, with considerations for translation to urban and built environments for humans

Introduction

Hippocampal neurogenesis is critical for improving learning, memory, and spatial navigation. Inhabiting and navigating spatial complexity is key to stimulating adult hippocampal neurogenesis (AHN) in rodents because they share similar hippocampal neuroplasticity characteristics with humans. AHN in humans has recently been found to persist until the tenth decade of life, but it declines with aging and is influenced by environmental enrichment. This systematic review investigated the impact of spatial complexity on neurogenesis and hippocampal plasticity in rodents, and discussed the translatability of these findings to human interventions.

Methods

Comprehensive searches were conducted on three databases in English: PubMed, Web of Science, and Scopus. All literature published until December 2023 was screened and assessed for eligibility. A total of 32 studies with original data were included, and the process is reported in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and checklist.

Results

The studies evaluated various models of spatial complexity in rodents, including environmental enrichment, changes to in-cage elements, complex layouts, and navigational mazes featuring novelty and intermittent complexity. A regression equation was formulated to synthesize key factors influencing neurogenesis, such as duration, physical activity, frequency of changes, diversity of complexity, age, living space size, and temperature.

Conclusion

Findings underscore the cognitive benefits of spatial complexity interventions and inform future translational research from rodents to humans. Home-cage enrichment and models like the Hamlet complex maze and the Marlau cage offer insight into how architectural design and urban navigational complexity can impact neurogenesis in humans. In-space changing complexity, with and without physical activity, is effective for stimulating neurogenesis. While evidence on intermittent spatial complexity in humans is limited, data from the COVID-19 pandemic lockdowns provide preliminary evidence. Existing equations relating rodent and human ages may allow for the translation of enrichment protocol durations from rodents to humans.

Appetitively motivated tasks in the IntelliCage reveal a higher motivational cost of spatial learning in male than female mice

The IntelliCage (IC) permits the assessment of the behavior and learning abilities of mice in a social home cage context. To overcome water deprivation as an aversive driver of learning, we developed protocols in which spatial learning is motivated appetitively by the preference of mice for sweetened over plain water. While plain water is available at all times, only correct task responses give access to sweetened water rewards. Under these conditions, C57BL/6J mice successfully mastered a corner preference task with the reversal and also learned a more difficult time-place task with reversal. However, the rate of responding to sweetened water decreased strongly with increasing task difficulty, indicating that learning challenges and reduced success in obtaining rewards decreased the motivation of the animals to seek sweetened water. While C57BL/6J mice of both sexes showed similar initial taste preferences and learned similarly well in simple learning tasks, the rate of responding to sweetened water and performance dropped more rapidly in male than in female mice in response to increasing learning challenges. Taken together, our data indicate that male mice can have a disadvantage relative to females in mastering difficult, appetitively motivated learning tasks, likely due to sex differences in value-based decision-making.

Refinement of IntelliCage protocols for complex cognitive tasks through replacement of drinking restrictions by incentive-disincentive paradigms

The IntelliCage allows automated testing of cognitive abilities of mice in a social home cage environment without handling by human experimenters. Restricted water access in combination with protocols in which only correct responses give access to water is a reliable learning motivator for hippocampus-dependent tasks assessing spatial memory and executive function. However, water restriction may negatively impact on animal welfare, especially in poor learners. To better comply with the 3R principles, we previously tested protocols in which water was freely available but additional access to sweetened water could be obtained by learning a task rule. While this purely appetitive motivation worked for simple tasks, too many mice lost interest in the sweet reward during more difficult hippocampus-dependent tasks. In the present study, we tested a battery of increasingly difficult spatial tasks in which water was still available without learning the task rule, but rendered less attractive either by adding bitter tasting quinine or by increasing the amount of work to obtain it. As in previous protocols, learning of the task rule provided access to water sweetened with saccharin. The two approaches of dual motivation were tested in two cohorts of female C57BL/6 N mice. Compared to purely appetitive motivation, both novel protocols strongly improved task engagement and increased task performance. Importantly, neither of the added disincentives had an adverse impact on liquid consumption, health status or body weight of the animals. Our results show that it is possible to refine test protocols in the IntelliCage so that they challenge cognitive functions without restricting access to water.