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Obesity is a growing health concern, mainly caused by poor dietary habits. Yet, accurately tracking the diet and food intake of individuals with obesity is challenging. Although 3D motion capture technology is becoming increasingly important in healthcare, its potential for detecting early signs of obesity has not been fully explored. In this research, we used a deep LSTM network trained with individual identity (identity-trained deep LSTM network) to analyze 3D time-series skeleton data from mouse models with diet-induced obesity. First, we analyzed the data from two different viewpoints: allocentric and egocentric. Second, we trained various deep recurrent networks (e.g., RNN, GRU, LSTM) to predict the identity. Lastly, we tested whether these models effectively encode obese-like motion representations by training a support vector classifier with the latent features from the last layer. Our experimental results indicate that the optimal performance is achieved when utilizing an identity-trained deep LSTM network in conjunction with an egocentric viewpoint. This approach suggests a new way to use deep learning to spot health risks in mouse models of obesity and should be useful for detecting early signs of obesity in humans.
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Impaired ion channels regulating Golgi pH lead to structural alterations in the Golgi apparatus, such as fragmentation, which is found, along with cognitive impairment, in Alzheimer's disease. However, the causal relationship between altered Golgi structure and cognitive impairment remains elusive due to the lack of understanding of ion channels in the Golgi apparatus of brain cells. Here, we identify that a transmembrane protein TMEM87A, renamed Golgi-pH-regulating cation channel (GolpHCat), expressed in astrocytes and neurons that contributes to hippocampus-dependent memory. We find that GolpHCat displays unique voltage-dependent currents, which is potently inhibited by gluconate. Additionally, we gain structural insights into the ion conduction through GolpHCat at the molecular level by determining three high-resolution cryogenic-electron microscopy structures of human GolpHCat. GolpHCat-knockout mice show fragmented Golgi morphology and altered protein glycosylation and functions in the hippocampus, leading to impaired spatial memory. These findings suggest a molecular target for Golgi-related diseases and cognitive impairment.
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Complexo de Golgi , Hipocampo , Camundongos Knockout , Neurônios , Animais , Humanos , Masculino , Camundongos , Astrócitos/metabolismo , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/patologia , Microscopia Crioeletrônica , Glicosilação , Complexo de Golgi/metabolismo , Células HEK293 , Hipocampo/metabolismo , Concentração de Íons de Hidrogênio , Canais Iônicos/metabolismo , Canais Iônicos/genética , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Memória/fisiologia , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Memória Espacial/fisiologiaRESUMO
The lateral hypothalamic area (LHA) regulates food intake and energy balance. Although LHA neurons innervate adipose tissues, the identity of neurons that regulate fat is undefined. Here we show that GABRA5-positive neurons in LHA (GABRA5LHA) polysynaptically project to brown and white adipose tissues in the periphery. GABRA5LHA are a distinct subpopulation of GABAergic neurons and show decreased pacemaker firing in diet-induced obesity mouse models in males. Chemogenetic inhibition of GABRA5LHA suppresses fat thermogenesis and increases weight gain, whereas gene silencing of GABRA5 in LHA decreases weight gain. In the diet-induced obesity mouse model, GABRA5LHA are tonically inhibited by nearby reactive astrocytes releasing GABA, which is synthesized by monoamine oxidase B (Maob). Gene silencing of astrocytic Maob in LHA facilitates fat thermogenesis and reduces weight gain significantly without affecting food intake, which is recapitulated by administration of a Maob inhibitor, KDS2010. We propose that firing of GABRA5LHA suppresses fat accumulation and selective inhibition of astrocytic GABA is a molecular target for treating obesity.
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Astrócitos , Obesidade , Masculino , Animais , Camundongos , Aumento de Peso , Neurônios , Modelos Animais de Doenças , Monoaminoxidase , Ácido gama-AminobutíricoRESUMO
Reactive astrogliosis is a hallmark of Alzheimer's disease (AD). However, a clinically validated neuroimaging probe to visualize the reactive astrogliosis is yet to be discovered. Here, we show that PET imaging with 11C-acetate and 18F-fluorodeoxyglucose (18F-FDG) functionally visualizes the reactive astrocyte-mediated neuronal hypometabolism in the brains with neuroinflammation and AD. To investigate the alterations of acetate and glucose metabolism in the diseased brains and their impact on the AD pathology, we adopted multifaceted approaches including microPET imaging, autoradiography, immunohistochemistry, metabolomics, and electrophysiology. Two AD rodent models, APP/PS1 and 5xFAD transgenic mice, one adenovirus-induced rat model of reactive astrogliosis, and post-mortem human brain tissues were used in this study. We further curated a proof-of-concept human study that included 11C-acetate and 18F-FDG PET imaging analyses along with neuropsychological assessments from 11 AD patients and 10 healthy control subjects. We demonstrate that reactive astrocytes excessively absorb acetate through elevated monocarboxylate transporter-1 (MCT1) in rodent models of both reactive astrogliosis and AD. The elevated acetate uptake is associated with reactive astrogliosis and boosts the aberrant astrocytic GABA synthesis when amyloid-ß is present. The excessive astrocytic GABA subsequently suppresses neuronal activity, which could lead to glucose uptake through decreased glucose transporter-3 in the diseased brains. We further demonstrate that 11C-acetate uptake was significantly increased in the entorhinal cortex, hippocampus and temporo-parietal neocortex of the AD patients compared to the healthy controls, while 18F-FDG uptake was significantly reduced in the same regions. Additionally, we discover a strong correlation between the patients' cognitive function and the PET signals of both 11C-acetate and 18F-FDG. We demonstrate the potential value of PET imaging with 11C-acetate and 18F-FDG by visualizing reactive astrogliosis and the associated neuronal glucose hypometablosim for AD patients. Our findings further suggest that the acetate-boosted reactive astrocyte-neuron interaction could contribute to the cognitive decline in AD.
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Doença de Alzheimer , Camundongos , Humanos , Ratos , Animais , Doença de Alzheimer/metabolismo , Fluordesoxiglucose F18/metabolismo , Astrócitos/metabolismo , Radioisótopos de Carbono/metabolismo , Gliose/diagnóstico por imagem , Encéfalo/patologia , Tomografia por Emissão de Pósitrons/métodos , Ácido gama-Aminobutírico/metabolismoRESUMO
Dopamine (DA) plays a vital role in brain physiology and pathology such as learning and memory, motor control, neurological diseases, and psychiatric diseases. In neurons, it has been well established that DA increases or decreases intracellular cyclic AMP (cAMP) through D1-like or D2-like dopamine receptors, respectively. In contrast, it has been elusive how astrocytes respond to DA via Ca2+ signaling and regulate synaptic transmission and reward systems. Previous studies suggest various molecular targets such as MAO-B, D1R, or D1R-D2R heteromer to modulate astrocytic Ca2+ signaling. However, which molecular target is utilized under what physiological condition remains unclear. Here, we show that DA-induced astrocytic Ca2+ signaling pathway switches during development: MAO-B is the major player at a young age (5-6 weeks), whereas DA receptors (DARs) are responsible for the adult period (8-12 weeks). DA-mediated Ca2+ response in the adult period was decreased by either D1R or D2R blockers, which are primarily known for cyclic AMP signaling (Gs and Gi pathway, respectively), suggesting that this Ca2+ response might be mediated through Gq pathway by D1R-D2R heterodimer. Moreover, DAR-mediated Ca2+ response was not blocked by TTX, implying that this response is not a secondary response caused by neuronal activation. Our study proposes an age-specific molecular target of DA-induced astrocytic Ca2+ signaling: MAO-B in young mice and DAR in adult mice.
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Astrócitos , Sinalização do Cálcio , Dopamina , Animais , Camundongos , Astrócitos/metabolismo , AMP Cíclico/metabolismo , Dopamina/metabolismo , Monoaminoxidase/metabolismo , Receptores Dopaminérgicos/metabolismoRESUMO
Monoamine oxidase B (MAOB) is a key enzyme for GABA production in astrocytes in several brain regions. To date, the role of astrocytic MAOB has been studied in MAOB null knockout (KO) mice, although MAOB is expressed throughout the body. Therefore, there has been a need for genetically engineered mice in which only astrocytic MAOB is targeted. Here, we generated an astrocyte-specific MAOB conditional KO (cKO) mouse line and characterized it in the cerebellar and striatal regions of the brain. Using the CRISPR-Cas9 gene-editing technique, we generated Maob floxed mice (B6-Maobem1Cjl/Ibs) which have floxed exons 2 and 3 of Maob with two loxP sites. By crossing these mice with hGFAP-CreERT2, we obtained Maob floxed::hGFAP-CreERT2 mice which have a property of tamoxifen-inducible ablation of Maob under the human GFAP (hGFAP) promoter. When we treated Maob floxed::hGFAP-CreERT2 mice with tamoxifen for 5 consecutive days, MAOB and GABA immunoreactivity were significantly reduced in striatal astrocytes as well as in Bergmann glia and lamellar astrocytes in the cerebellum, compared to sunflower oil-injected control mice. Moreover, astrocyte-specific MAOB cKO led to a 74.6% reduction in tonic GABA currents from granule cells and a 76.8% reduction from medium spiny neurons. Our results validate that astrocytic MAOB is a critical enzyme for the synthesis of GABA in astrocytes. We propose that this new mouse line could be widely used in studies of various brain diseases to elucidate the pathological role of astrocytic MAOB in the future.
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Alzheimer's disease (AD) is one of the foremost neurodegenerative diseases, characterized by beta-amyloid (Aß) plaques and significant progressive memory loss. In AD, astrocytes are proposed to take up and clear Aß plaques. However, how Aß induces pathogenesis and memory impairment in AD remains elusive. We report that normal astrocytes show non-cyclic urea metabolism, whereas Aß-treated astrocytes show switched-on urea cycle with upregulated enzymes and accumulated entering-metabolite aspartate, starting-substrate ammonia, end-product urea, and side-product putrescine. Gene silencing of astrocytic ornithine decarboxylase-1 (ODC1), facilitating ornithine-to-putrescine conversion, boosts urea cycle and eliminates aberrant putrescine and its toxic byproducts ammonia and H2O2 and its end product GABA to recover from reactive astrogliosis and memory impairment in AD. Our findings implicate that astrocytic urea cycle exerts opposing roles of beneficial Aß detoxification and detrimental memory impairment in AD. We propose ODC1 inhibition as a promising therapeutic strategy for AD to facilitate removal of toxic molecules and prevent memory loss.
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Doença de Alzheimer , Doença de Alzheimer/metabolismo , Amônia/metabolismo , Peptídeos beta-Amiloides/farmacologia , Astrócitos/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Placa Amiloide/metabolismo , Putrescina , Ureia/metabolismoRESUMO
Light is a powerful external cue modulating the biological rhythm of internal clock neurons in the suprachiasmatic nucleus (SCN). GABA signaling in SCN is critically involved in this process. Both phasic and tonic modes of GABA signaling exist in SCN. Of the two modes, the tonic mode of GABA signaling has been implicated in light-mediated synchrony of SCN neurons. However, modulatory effects of external light on tonic GABA signalling are yet to be explored. Here, we systematically characterized electrophysiological properties of the clock neurons and determined the spatio-temporal profiles of tonic GABA current. Based on the whole-cell patch-clamp recordings from 76 SCN neurons, the cells with large tonic GABA current (>15 pA) were more frequently found in dorsal SCN. Moreover, tonic GABA current in SCN was highly correlated with the frequency of spontaneous inhibitory postsynaptic current (sIPSC), raising a possibility that tonic GABA current is due to spill-over from synaptic release. Interestingly, tonic GABA current was inversely correlated with slice-to-patch time interval, suggesting a critical role of retinal light exposure in intact brain for an induction of tonic GABA current in SCN. To test this possibility, we obtained meticulously prepared retina-attached SCN slices and successfully recorded tonic and phasic GABA signaling in SCN neurons. For the first time, we observed an early-onset, long-lasting tonic GABA current, followed by a slow-onset, short-lasting increase in the phasic GABA frequency, upon direct light-illumination of the attached retina. This result provides the first evidence that external light cue can directly trigger both tonic and phasic GABA signaling in SCN cell. In conclusion, we propose tonic GABA as the key mediator of external light in SCN.
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Ritmo Circadiano , Núcleo Supraquiasmático , Técnicas de Patch-Clamp , Retina , Ácido gama-Aminobutírico/farmacologiaRESUMO
The TMEM43 has been studied in human diseases such as arrhythmogenic right ventricular cardiomyopathy type 5 (ARVC5) and auditory neuropathy spectrum disorder (ANSD). In the heart, the p.(Ser358Leu) mutation has been shown to alter intercalated disc protein function and disturb beating rhythms. In the cochlea, the p.(Arg372Ter) mutation has been shown to disrupt connexin-linked function in glia-like supporting cells (GLSs), which maintain inner ear homeostasis for hearing. The TMEM43-p.(Arg372Ter) mutant knock-in mice displayed a significantly reduced passive conductance current in the cochlear GLSs, raising a possibility that TMEM43 is essential for mediating the passive conductance current in GLSs. In the brain, the two-pore-domain potassium (K2P) channels are generally known as the "leak channels" to mediate background conductance current, raising another possibility that K2P channels might contribute to the passive conductance current in GLSs. However, the possible association between TMEM43 and K2P channels has not been investigated yet. In this study, we examined whether TMEM43 physically interacts with one of the K2P channels in the cochlea, KCNK3 (TASK-1). Utilizing co-immunoprecipitation (IP) assay and Duolink proximity ligation assay (PLA), we revealed that TMEM43 and TASK-1 proteins could directly interact. Genetic modifications further delineated that the intracellular loop domain of TMEM43 is responsible for TASK-1 binding. In the end, gene-silencing of Task-1 resulted in significantly reduced passive conductance current in GLSs. Together, our findings demonstrate that TMEM43 and TASK-1 form a protein-protein interaction in the cochlea and provide the possibility that TASK-1 is a potential contributor to the passive conductance current in GLSs.
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In the era of COVID-19 outbreak, various efforts are undertaken to develop a quick, easy, inexpensive, and accurate way for diagnosis. Although many commercial diagnostic kits are available, detailed scientific evaluation is lacking, making the public vulnerable to fear of false-positive results. Moreover, current tissue sampling method from respiratory tract requires personal contact of medical staff with a potential asymptomatic SARSCOV-2 carrier and calls for safe and less invasive sampling method. Here, we have developed a convenient detection protocol for SARS-COV-2 based on a non-invasive saliva self-sampling method by extending our previous studies on development of a laboratory-safe and low-cost detection protocol based on qRT-PCR. We tested and compared various self-sampling methods of self-pharyngeal swab and self-saliva sampling from non-carrier volunteers. We found that the self-saliva sampling procedure gave expected negative results from all of the non-carrier volunteers within 2 hours, indicating cost-effectiveness, speed and reliability of the saliva-based method. For an automated assessment of the sampling quality and degree of positivity for COVID-19, we developed scalable formulae based on a logistic classification model using both cycle threshold and melting temperature from the qRT-PCR results. Our newly developed protocol will allow easy sampling and spatial-separation between patient and experimenter for guaranteed safety. Furthermore, our newly established risk assessment formula can be applied to a large-scale diagnosis in health institutions and agencies around the world.
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OBJECTIVES: The association between pet sensitization and pet ownership remains unclear. Therefore, we aimed to elucidate the association between pet sensitization and pet ownership by age. METHODS: We retrospectively reviewed 2,883 patients who visited our allergy clinic for nasal symptoms from January 2003 to December 2014, of whom 1,957 patients with data on skin-prick tests and questionnaire responses were included and divided into adults (age >19 years) and children (age ≤19 years). The association between pet sensitization and pet ownership was evaluated in both groups. RESULTS: Among children, dog and cat sensitization showed no associations with dog and cat ownership, respectively. However, among adults, dog sensitization was significantly associated with dog ownership (odds ratio [OR], 3.283; P<0.001), and cat sensitization with cat ownership (OR, 13.732; P<0.001). After adjustment for age, sex, familial history of allergy, sinusitis, diabetes mellitus, other pet ownership, and non-pet sensitization, significant associations remained between dog sensitization and dog ownership (adjusted OR [aOR], 3.881; P<0.001), and between cat sensitization and cat ownership (aOR, 10.804; P<0.001) among adults. Dog ownership did not show any association with allergic rhinitis, asthma, or atopic dermatitis, whereas atopic dermatitis had a significant association with cat ownership in adults (aOR, 4.840; P<0.001). CONCLUSION: Pet ownership in adulthood increased the risk of pet sensitization. However, pet ownership was not associated with the prevalence of atopic disorders, regardless of age, except for atopic dermatitis and cat ownership in adults.
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A single stressful event can cause morphologic and functional changes in neurons and even malfunction of vascular systems, which can lead to acute stress disorder or post-traumatic stress disorder. However, there is a lack of evidence regarding how acute stress impacts neuronal activity, the concurrent vascular response, and the relationship between these two factors, which is defined as neurovascular coupling. Here, using in vivo two-photon imaging, we found that NMDA-evoked calcium transients of excitatory neurons were impaired and that vasodilation of penetrating arterioles was concomitantly disrupted in acutely stressed male mice. Furthermore, acute stress altered the relationship between excitatory neuronal calcium coherence and vascular responses. By measuring NMDA-evoked excitatory and inhibitory neuronal calcium activity in acute brain slices, we confirmed that neuronal coherence both between excitatory neurons and between excitatory and inhibitory neurons was reduced by acute stress but restored by blockade of glucocorticoid receptor signaling. Furthermore, the ratio of sEPSCs to sIPSCs was altered by acute stress, suggesting that the excitation-inhibition balance was disrupted by acute stress. In summary, in vivo, ex vivo, and whole-cell recording studies demonstrate that acute stress modifies excitatory-inhibitory neuronal coherence, disrupts the excitation-inhibition balance, and causes consequent neurovascular coupling changes, providing critical insights into the neural mechanism of stress-induced disorders.SIGNIFICANCE STATEMENT Acute stress can cause pathologic conditions, such as acute stress disorder and post-traumatic stress disorder, by affecting the functions of neurons and blood vessels. However, investigations into the impacts of acute stress on neurovascular coupling, the tight connection between local neural activity and subsequent blood flow changes, are lacking. Through investigations at the in vivo, ex vivo, and whole-cell recording levels, we found that acute stress alters the NMDA-evoked vascular response, impairs the function and coherence of excitatory and inhibitory neurons, and disrupts the excitatory and inhibitory balance. These novel findings provide insights into the relevance of the excitatory-inhibitory balance, neuronal coherence, and neurovascular coupling to stress-induced disorders.
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Neurônios/patologia , Acoplamento Neurovascular/fisiologia , Estresse Psicológico/patologia , Doença Aguda , Animais , Sinalização do Cálcio , Circulação Cerebrovascular/fisiologia , Corticosterona/fisiologia , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , N-Metilaspartato/farmacologia , Inibição Neural , Técnicas de Patch-Clamp , Receptores de Glucocorticoides/fisiologia , Restrição FísicaRESUMO
OBJECTIVES: Currently, epidemiological data on allergic rhinitis collected through the skin prick test are scarce. Moreover, the relationship of age and sex to allergic rhinitis is not comprehensively understood. This study aimed to characterize allergic rhinitis and the associated clinical manifestations by age and sex. METHODS: We retrospectively investigated data from 2883 patients who visited a single university hospital for rhinitis symptoms between January 2003 and December 2014. Of these 2883 patients, 1964 who underwent a skin prick test with 11 standardized allergen extracts and completed a nasal symptom questionnaire were enrolled. The clinical characteristics of allergen sensitization and nasal symptoms were analyzed by sex and age distribution. RESULTS: The prevalence of allergen sensitization progressively decreased with age after peaking at between 20 and 29 years. The sensitization rate was higher in males than in females (P = .046). The sensitization rate to house dust mites decreased with age, while sensitization to mugwort and ragweed increased. Six allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, mugwort, trees, ragweed, and cats) were sufficient to identify >96% of patients with allergen sensitization. Nasal obstruction tended to decrease with age and was more prevalent in males (P = .002) than in females, while rhinorrhea (P = .007) and itching (P = .013) were more prevalent in females. Total nasal symptom scores did not differ by sex. CONCLUSIONS: The clinical characteristics of allergic rhinitis, including allergen-sensitization patterns and related symptoms, varied by age and sex. Six common allergens could be sufficient to generate a cost-effective tool to identify allergic rhinitis.
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Rinite Alérgica/diagnóstico , Adolescente , Adulto , Idoso , Alérgenos/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Rinite Alérgica/imunologia , Fatores de Tempo , Adulto JovemRESUMO
Low-intensity, low-frequency ultrasound (LILFU) is the next-generation, non-invasive brain stimulation technology for treating various neurological and psychiatric disorders. However, the underlying cellular and molecular mechanism of LILFU-induced neuromodulation has remained unknown. Here, we report that LILFU-induced neuromodulation is initiated by opening of TRPA1 channels in astrocytes. The Ca2+ entry through TRPA1 causes a release of gliotransmitters including glutamate through Best1 channels in astrocytes. The released glutamate activates NMDA receptors in neighboring neurons to elicit action potential firing. Our results reveal an unprecedented mechanism of LILFU-induced neuromodulation, involving TRPA1 as a unique sensor for LILFU and glutamate-releasing Best1 as a mediator of glia-neuron interaction. These discoveries should prove to be useful for optimization of human brain stimulation and ultrasonogenetic manipulations of TRPA1.
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Astrócitos/metabolismo , Ácido Glutâmico/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Canal de Cátion TRPA1/genética , Ultrassonografia , Animais , Masculino , Camundongos , Distribuição Aleatória , Canal de Cátion TRPA1/metabolismoRESUMO
In the brain, a reduction in extracellular osmolality causes water-influx and swelling, which subsequently triggers Cl-- and osmolytes-efflux via volume-regulated anion channel (VRAC). Although LRRC8 family has been recently proposed as the pore-forming VRAC which is activated by low cytoplasmic ionic strength but not by swelling, the molecular identity of the pore-forming swelling-dependent VRAC (VRACswell) remains unclear. Here we identify and characterize Tweety-homologs (TTYH1, TTYH2, TTYH3) as the major VRACswell in astrocytes. Gene-silencing of all Ttyh1/2/3 eliminated hypo-osmotic-solution-induced Cl- conductance (ICl,swell) in cultured and hippocampal astrocytes. When heterologously expressed in HEK293T or CHO-K1 cells, each TTYH isoform showed a significant ICl,swell with similar aquaporin-4 dependency, pharmacological properties and glutamate permeability as ICl,swell observed in native astrocytes. Mutagenesis-based structure-activity analysis revealed that positively charged arginine residue at 165 in TTYH1 and 164 in TTYH2 is critical for the formation of the channel-pore. Our results demonstrate that TTYH family confers the bona fide VRACswell in the brain.
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Tonic inhibition in the brain is mediated through an activation of extrasynaptic GABAA receptors by the tonically released GABA, resulting in a persistent GABAergic inhibitory action. It is one of the key regulators for neuronal excitability, exerting a powerful action on excitation/inhibition balance. We have previously reported that astrocytic GABA, synthesized by monoamine oxidase B (MAOB), mediates tonic inhibition via GABA-permeable bestrophin 1 (Best1) channel in the cerebellum. However, the role of astrocytic GABA in regulating neuronal excitability, synaptic transmission, and cerebellar brain function has remained elusive. Here, we report that a reduction of tonic GABA release by genetic removal or pharmacological inhibition of Best1 or MAOB caused an enhanced neuronal excitability in cerebellar granule cells (GCs), synaptic transmission at the parallel fiber-Purkinje cell (PF-PC) synapses, and motor performance on the rotarod test, whereas an augmentation of tonic GABA release by astrocyte-specific overexpression of MAOB resulted in a reduced neuronal excitability, synaptic transmission, and motor performance. The bidirectional modulation of astrocytic GABA by genetic alteration of Best1 or MAOB was confirmed by immunostaining and in vivo microdialysis. These findings indicate that astrocytes are the key player in motor coordination through tonic GABA release by modulating neuronal excitability and could be a good therapeutic target for various movement and psychiatric disorders, which show a disturbed excitation/inhibition balance.
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Astrócitos/metabolismo , Cerebelo/metabolismo , Desempenho Psicomotor/fisiologia , Células de Purkinje/metabolismo , Transmissão Sináptica/fisiologia , Ácido gama-Aminobutírico/metabolismo , Animais , Astrócitos/citologia , Bestrofinas/genética , Bestrofinas/metabolismo , Cerebelo/citologia , Camundongos Endogâmicos BALB C , Camundongos Knockout , Monoaminoxidase/genética , Monoaminoxidase/metabolismo , Células de Purkinje/citologia , Ácido gama-Aminobutírico/genéticaRESUMO
Circadian rhythm is defined as a 24-hour biological oscillation, which persists even without any external cues but also can be re-entrained by various environmental cues. One of the widely accepted circadian rhythm behavioral experiment is measuring the wheel-running activity (WRA) of rodents. However, the price for commercially available WRA recording system is not easily affordable for researchers due to high-cost implementation of sensors for wheel rotation. Here, we developed a cost-effective and comprehensive system for circadian rhythm recording by measuring the house-keeping activities (HKA). We have monitored animal's HKA as electrical signal by simply connecting animal housing cage with a standard analog/digital converter: input to the metal lid and ground to the metal grid floor. We show that acquired electrical signals are combined activities of eating, drinking and natural locomotor behaviors which are well-known indicators of circadian rhythm. Post-processing of measured electrical signals enabled us to draw actogram, which verifies HKA to be reliable circadian rhythm indicator. To provide easy access of HKA recording system for researchers, we have developed user-friendly MATLAB-based software, Circa Analysis. This software provides functions for easy extraction of scalable "touch activity" from raw data files by automating seven steps of post-processing and drawing actograms with highly intuitive user-interface and various options. With our cost-effective HKA circadian rhythm recording system, we have estimated the cost of our system to be less than $150 per channel. We anticipate our system will benefit many researchers who would like to study circadian rhythm.