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1.
Neuron ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38870929

RESUMO

In classical cerebellar learning, Purkinje cells (PkCs) associate climbing fiber (CF) error signals with predictive granule cells (GrCs) that were active just prior (∼150 ms). The cerebellum also contributes to behaviors characterized by longer timescales. To investigate how GrC-CF-PkC circuits might learn seconds-long predictions, we imaged simultaneous GrC-CF activity over days of forelimb operant conditioning for delayed water reward. As mice learned reward timing, numerous GrCs developed anticipatory activity ramping at different rates until reward delivery, followed by widespread time-locked CF spiking. Relearning longer delays further lengthened GrC activations. We computed CF-dependent GrC→PkC plasticity rules, demonstrating that reward-evoked CF spikes sufficed to grade many GrC synapses by anticipatory timing. We predicted and confirmed that PkCs could thereby continuously ramp across seconds-long intervals from movement to reward. Learning thus leads to new GrC temporal bases linking predictors to remote CF reward signals-a strategy well suited for learning to track the long intervals common in cognitive domains.

2.
Membranes (Basel) ; 13(8)2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37623768

RESUMO

A cell filtration platform that affords accurate size separation and minimizes fouling was developed. The platform features an ultra-thin porous membrane (UTM) filter, a pumping head filtration with backflush (PHF), and cell size measurement (CSM) software. The UTM chip is an ultrathin free-standing membrane with a large window area of 0.68 mm2, a pore diameter of 5 to 9 µm, and a thickness of less than 0.9 µm. The PHF prevents filter fouling. The CSM software analyzes the size distributions of the supernatants and subnatants of isolated cells and presents the data visually. The D99 particle size of cells of the chronic myeloid leukemia (CML) line K562 decreased from 22.2 to 17.5 µm after passage through a 5-µm filter. K562 cells could be separated by careful selection of the pore size; the recovery rate attained 91.3%. The method was compared to conventional blocking models by evaluating the mean square errors (MSEs) between the measured and calculated filtering volumes. The filtering rate was fitted by a linear regression model with a significance that exceeded 0.99 based on the R2 value. The platform can be used to separate various soft biomaterials and afford excellent stability during filtration.

3.
ACS Appl Mater Interfaces ; 15(21): 26069-26080, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37192384

RESUMO

Tangent flow-driven ultrafiltration (TF-UF) is an efficient isolation process of milk exosomes without morphological deformation. However, the TF-UF approach with micro-ultrafiltration SiNx membrane filters suffers from the clogging and fouling of micro-ultrafiltration membrane filter pores with large bioparticles. Thus, it is limited in the long term, continuous isolation of large quantities of exosomes. In this work, we introduced electrophoretic oscillation (EPO) in the TF-UF approach to remove pore clogging and fouling of with micro-ultrafiltration SiNx membrane filters by large bioparticles. As a result, the combined EPO-assisted TF (EPOTF) filtration can isolate large quantities of bovine milk exosomes without deformation. Furthermore, several morphological and biological analyses confirmed that the EPOTF filtration approach could isolate the milk exosomes in high concentrations with high purity and intact morphology. In addition, the uptake test of fluorescent-labeled exosomes by the keratinocyte cells visualized the biological function of purified exosomes. Hence, compared to the TF-UF process, the EPOTF filtration produced a higher yield of bovine milk exosomes without stopping the filtering process for over 200 h. Therefore, this isolation process enables scalable and continuous production of morphologically intact exosomes from bovine milk, suggesting that high-quality exosome purification is possible for future applications such as drug nanocarriers, diagnosis, and treatments.


Assuntos
Incrustação Biológica , Exossomos , Animais , Ultrafiltração , Leite , Incrustação Biológica/prevenção & controle , Filtração , Membranas Artificiais
4.
Tour Manag Perspect ; 42: 100950, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35281214

RESUMO

The COVID-19 pandemic increased attention to product/service-customer relationships in the context of events where social gatherings take place. Event attributes have been a topic of continued interest in research and practice. Due to COVID-19, however, event attendees' preferences and requirements related to personal values and satisfaction may be changing. Using a sequential mixed-method exploratory strategy with means-end chain theory and the Kano model as a research framework, this study identifies important event attributes, benefits, personal values, and specific satisfaction attributes. Key findings highlight pleasure and excitement and sense of safety as salient personal values. Respondents also found health/safety attributes particularly important, considering them must-be attributes. Providing health/safety services prior to the event would be effective in decreasing dissatisfaction. Implications for researchers and practitioners are discussed.

5.
Cell ; 185(1): 9-41, 2022 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-34995519

RESUMO

Recent progress in fluorescence imaging allows neuroscientists to observe the dynamics of thousands of individual neurons, identified genetically or by their connectivity, across multiple brain areas and for extended durations in awake behaving mammals. We discuss advances in fluorescent indicators of neural activity, viral and genetic methods to express these indicators, chronic animal preparations for long-term imaging studies, and microscopes to monitor and manipulate the activity of large neural ensembles. Ca2+ imaging studies of neural activity can track brain area interactions and distributed information processing at cellular resolution. Across smaller spatial scales, high-speed voltage imaging reveals the distinctive spiking patterns and coding properties of targeted neuron types. Collectively, these innovations will propel studies of brain function and dovetail with ongoing neuroscience initiatives to identify new neuron types and develop widely applicable, non-human primate models. The optical toolkit's growing sophistication also suggests that "brain observatory" facilities would be useful open resources for future brain-imaging studies.


Assuntos
Mapeamento Encefálico/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Neocórtex/diagnóstico por imagem , Neocórtex/metabolismo , Neurônios/metabolismo , Imagem Óptica/métodos , Animais , Cálcio/metabolismo , Camundongos , Modelos Animais , Neurociências/métodos
6.
Sensors (Basel) ; 21(20)2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34696037

RESUMO

Sampling-based PLLs have become a new research trend due to the possibility of removing the frequency divider (FDIV) from the feedback path, where the FDIV increases the contribution of in-band noise by the factor of dividing ratio square (N2). Between two possible sampling methods, sub-sampling and reference-sampling, the latter provides a relatively wide locking range, as the slower input reference signal is sampled with the faster VCO output signal. However, removal of FDIV makes the PLL not feasible to implement fractional-N operation based on varying divider ratios through random sequence generators, such as a Delta-Sigma-Modulator (DSM). To address the above design challenges, we propose a reference-sampling-based calibration-free fractional-N PLL (RSFPLL) with a phase-interpolator-linked sampling clock generator (PSCG). The proposed RSFPLL achieves fractional-N operations through phase-interpolator (PI)-based multi-phase generation instead of a typical frequency divider or digital-to-time converter (DTC). In addition, to alleviate the power burden arising from VCO-rated sampling, a flexible mask window generation method has been used that only passes a few sampling clocks near the point of interest. The prototype PLL system is designed with a 65 nm CMOS process with a chip size of 0.42 mm2. It achieves 322 fs rms jitter, -240.7 dB figure-of-merit (FoM), and -44.06 dBc fractional spurs with 8.17 mW power consumption.

7.
Cell ; 184(14): 3731-3747.e21, 2021 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-34214470

RESUMO

In motor neuroscience, state changes are hypothesized to time-lock neural assemblies coordinating complex movements, but evidence for this remains slender. We tested whether a discrete change from more autonomous to coherent spiking underlies skilled movement by imaging cerebellar Purkinje neuron complex spikes in mice making targeted forelimb-reaches. As mice learned the task, millimeter-scale spatiotemporally coherent spiking emerged ipsilateral to the reaching forelimb, and consistent neural synchronization became predictive of kinematic stereotypy. Before reach onset, spiking switched from more disordered to internally time-locked concerted spiking and silence. Optogenetic manipulations of cerebellar feedback to the inferior olive bi-directionally modulated neural synchronization and reaching direction. A simple model explained the reorganization of spiking during reaching as reflecting a discrete bifurcation in olivary network dynamics. These findings argue that to prepare learned movements, olivo-cerebellar circuits enter a self-regulated, synchronized state promoting motor coordination. State changes facilitating behavioral transitions may generalize across neural systems.


Assuntos
Movimento/fisiologia , Rede Nervosa/fisiologia , Potenciais de Ação/fisiologia , Animais , Cálcio/metabolismo , Cerebelo/fisiologia , Sincronização Cortical , Membro Anterior/fisiologia , Interneurônios/fisiologia , Aprendizagem , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Neurológicos , Atividade Motora/fisiologia , Núcleo Olivar/fisiologia , Optogenética , Células de Purkinje/fisiologia , Comportamento Estereotipado , Análise e Desempenho de Tarefas
8.
Physiol Behav ; 239: 113499, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34146575

RESUMO

Mitragynine (MG), the most prevalent bioactive alkaloid in kratom, displays nanomolar affinity for µ, κ and δ opioid receptors and produces opioid-dependent antinociception and dependence in rats. Here, using a battery of behavioral assays, we investigated MG effects in planarians. Acute MG exposure (< 100 µM) did not affect planarian motility or environmental preference, but reduced motility was detected during abstinence from chronic MG (1, 10 µM). MG (10 µM) produced place conditioning effects that were reduced by naltrexone (10  µΜ). These results suggest that MG produces opioid-sensitive reinforcing effects in planarians and MG pharmacology is conserved across different species.


Assuntos
Mitragyna , Planárias , Alcaloides de Triptamina e Secologanina , Animais , Naltrexona/farmacologia , Ratos , Alcaloides de Triptamina e Secologanina/farmacologia
9.
Proc Natl Acad Sci U S A ; 118(23)2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34088841

RESUMO

Cerebellar granule cells (GrCs) are usually regarded as a uniform cell type that collectively expands the coding space of the cerebellum by integrating diverse combinations of mossy fiber inputs. Accordingly, stable molecularly or physiologically defined GrC subtypes within a single cerebellar region have not been reported. The only known cellular property that distinguishes otherwise homogeneous GrCs is the correspondence between GrC birth timing and the depth of the molecular layer to which their axons project. To determine the role birth timing plays in GrC wiring and function, we developed genetic strategies to access early- and late-born GrCs. We initiated retrograde monosynaptic rabies virus tracing from control (birth timing unrestricted), early-born, and late-born GrCs, revealing the different patterns of mossy fiber input to GrCs in vermis lobule 6 and simplex, as well as to early- and late-born GrCs of vermis lobule 6: sensory and motor nuclei provide more input to early-born GrCs, while basal pontine and cerebellar nuclei provide more input to late-born GrCs. In vivo multidepth two-photon Ca2+ imaging of axons of early- and late-born GrCs revealed representations of diverse task variables and stimuli by both populations, with modest differences in the proportions encoding movement, reward anticipation, and reward consumption. Our results suggest neither organized parallel processing nor completely random organization of mossy fiber→GrC circuitry but instead a moderate influence of birth timing on GrC wiring and encoding. Our imaging data also provide evidence that GrCs can represent generalized responses to aversive stimuli, in addition to recently described reward representations.


Assuntos
Córtex Cerebelar/crescimento & desenvolvimento , Fibras Nervosas/metabolismo , Animais , Animais Recém-Nascidos , Córtex Cerebelar/virologia , Camundongos , Camundongos Transgênicos , Fibras Nervosas/virologia , Vírus da Raiva/metabolismo
10.
Nano Lett ; 21(4): 1659-1665, 2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33533624

RESUMO

Batteries for contact lenses fabricated by conventional methods could cause severe damage to the eyes if broken. Herein, we present flexible aqueous batteries that operate in tears and provide a safe power supply to smart contact lenses. Nanocomposite flexible electrodes of carbon nanotubes and Prussian blue analogue nanoparticles for cathode and anode were embedded in UV-polymerized hydrogel as not only a soft contact lens but also an ion-permeable separator. The battery exhibited a discharging capacity of 155 µAh in an aqueous electrolyte of 0.15 M Na-ions and 0.02 M K-ions, equivalent to the ionic concentration of tears. The power supply was enough to operate a low-power static random-access memory. In addition, we verified the mechanical stability, biocompatibility and compatibility with a contact lens cleaning solution. It could ultimately enable a safe power supply for smart contact lenses without risk of injury due to the leakage or breakage of the battery.


Assuntos
Lentes de Contato Hidrofílicas , Nanocompostos , Nanotubos de Carbono , Fontes de Energia Elétrica , Ferrocianetos , Lágrimas
11.
Oral Dis ; 27(4): 1052-1058, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32790928

RESUMO

OBJECTIVES: The objective of this retrospective observational study was to determine the incidence of direct-acting oral anti-coagulant (DOA) use in patients receiving invasive dental procedures. The secondary objective was to investigate the precautionary measures implemented and the post/intraoperative complications associated with DOA use. METHODS: Electronic record database, Axium, was retrospectively reviewed, and patients using NGOA and treated between 2010 and 2017 were identified. Charts of patients who underwent invasive dental procedures were further reviewed to investigate the preoperative/intraoperative precautionary measures taken and identify any intraoperative/postoperative complications. RESULTS: A total of 130 patients were identified, with their annual number steadily rising from 12 in 2011 to 52 in 2016. Among those, 64 patients (49.23%) underwent invasive dental procedures. Pretreatment medical consults were obtained in all patients undergoing invasive procedures; however, only 7 (10.94%) were instructed to discontinue their DOA. Preoperative laboratory testing was obtained for two patients. Intraoperatively, 34 (53.13%) cases of excessive bleeding were reported, all were locally controlled with hemostatic agents. Only 4 instances of postoperative complications were documented. CONCLUSIONS: Despite the rise in the use of DOA, there is no consistent pattern for preoperative laboratory testing and DOA discontinuations. Expert consensus may be of great importance to develop practice guidelines.


Assuntos
Anticoagulantes , Hemorragia Pós-Operatória , Anticoagulantes/efeitos adversos , Humanos , Hemorragia Pós-Operatória/induzido quimicamente , Hemorragia Pós-Operatória/epidemiologia , Hemorragia Pós-Operatória/prevenção & controle , Estudos Retrospectivos
12.
Sensors (Basel) ; 20(8)2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32344711

RESUMO

Ultra-wideband (UWB) wireless communication is prospering as a powerful partner of the Internet-of-things (IoT). Due to the ongoing development of UWB wireless communications, the demand for high-speed and medium resolution analog-to-digital converters (ADCs) continues to grow. The successive approximation register (SAR) ADCs are the most powerful candidate to meet these demands, attracting both industries and academia. In particular, recent time-interleaved SAR ADCs show that multi-giga sample per second (GS/s) can be achieved by overcoming the challenges of high-speed implementation of existing SAR ADCs. However, there are still critical issues that need to be addressed before the time-interleaved SAR ADCs can be applied in real commercial applications. The most well-known problem is that the time-interleaved SAR ADC architecture requires multiple sub-ADCs, and the mismatches between these sub-ADCs can significantly degrade overall ADC performance. And one of the most difficult mismatches to solve is the sampling timing skew. Recently, research to solve this timing-skew problem has been intensively studied. In this paper, we focus on the cutting-edge timing-skew calibration technique using a window detector. Based on the pros and cons analysis of the existing techniques, we come up with an idea that increases the benefits of the window detector-based timing-skew calibration techniques and minimizes the power and area overheads. Finally, through the continuous development of this idea, we propose a timing-skew calibration technique using a comparator offset-based window detector. To demonstrate the effectiveness of the proposed technique, intensive works were performed, including the design of a 7-bit, 2.5 GS/s 5-channel time-interleaved SAR ADC and various simulations, and the results prove excellent efficacy of signal-to-noise and distortion ratio (SNDR) and spurious-free dynamic range (SFDR) of 40.79 dB and 48.97 dB at Nyquist frequency, respectively, while the proposed window detector occupies only 6.5% of the total active area, and consumes 11% of the total power.

13.
Nat Protoc ; 15(3): 1237-1254, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32034393

RESUMO

Skilled forelimb behaviors are among the most important for studying motor learning in multiple species including humans. This protocol describes learned forelimb tasks for mice using a two-axis robotic manipulandum. Our device provides a highly compact adaptation of actuated planar two-axis arms that is simple and inexpensive to construct. This paradigm has been dominant for decades in primate motor neuroscience. Our device can generate arbitrary virtual movement tracks, arbitrary time-varying forces or arbitrary position- or velocity-dependent force patterns. We describe several example tasks permitted by our device, including linear movements, movement sequences and aiming movements. We provide the mechanical drawings and source code needed to assemble and control the device, and detail the procedure to train mice to use the device. Our software can be simply extended to allow users to program various customized movement assays. The device can be assembled in a few days, and the time to train mice on the tasks that we describe ranges from a few days to several weeks. Furthermore, the device is compatible with various neurophysiological techniques that require head fixation.


Assuntos
Membro Anterior , Movimento , Desempenho Psicomotor/fisiologia , Robótica/instrumentação , Robótica/métodos , Animais , Fenômenos Biomecânicos , Cabeça , Camundongos
14.
IEEE Trans Biomed Eng ; 67(9): 2482-2489, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31902752

RESUMO

OBJECTIVE: Photoacoustics has been evolving rapidly in the recent several decades. With the aim of clinical translation, a photoacoustic imaging platform with a portable system size, a miniaturized imaging probe, and convenient handheld capability is of great demand. METHODS: In this work, by adopting an ultrathin central-holed matrix array and a compact coaxial photoacoustic design, a water-free handheld photoacoustic imager is developed (weight: 44 g). Optical Monte Carlo simulation and acoustic k-wave simulation are performed to confirm a relatively homogenous photoacoustic sensitivity distribution within a wide field of view (larger than 10 × 10 × 10 mm3). RESULTS: Imaging resolution characterized by imaging two hairs is estimated to be about 0.80 mm in the lateral direction and 0.73 mm in the axial direction. To demonstrate the handheld capability in real time, handheld imaging guided needle biopsy in the rat's abdomen is performed at a rate of about 10 Hz (CNR ∼ 14.3 dB). Furthermore, handheld imaging is also demonstrated on visualizing vasculature (mainly cephalic vein) in the human arm (CNR > 4.1 dB). CONCLUSION: Results demonstrate that the volumetric photoacoustic imaging system using a central-holed 2D matrix array is an attractive choice for achieving convenient handheld operation in real time. SIGNIFICANCE: Such a compact handheld design may promote the clinical translation of photoacoustic technique.


Assuntos
Diagnóstico por Imagem , Técnicas Fotoacústicas , Método de Monte Carlo , Som , Análise Espectral
15.
Cell ; 177(3): 669-682.e24, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30929904

RESUMO

Throughout mammalian neocortex, layer 5 pyramidal (L5) cells project via the pons to a vast number of cerebellar granule cells (GrCs), forming a fundamental pathway. Yet, it is unknown how neuronal dynamics are transformed through the L5→GrC pathway. Here, by directly comparing premotor L5 and GrC activity during a forelimb movement task using dual-site two-photon Ca2+ imaging, we found that in expert mice, L5 and GrC dynamics were highly similar. L5 cells and GrCs shared a common set of task-encoding activity patterns, possessed similar diversity of responses, and exhibited high correlations comparable to local correlations among L5 cells. Chronic imaging revealed that these dynamics co-emerged in cortex and cerebellum over learning: as behavioral performance improved, initially dissimilar L5 cells and GrCs converged onto a shared, low-dimensional, task-encoding set of neural activity patterns. Thus, a key function of cortico-cerebellar communication is the propagation of shared dynamics that emerge during learning.


Assuntos
Cerebelo/metabolismo , Neocórtex/metabolismo , Animais , Comportamento Animal , Cálcio/metabolismo , Membro Anterior/fisiologia , Camundongos , Camundongos Transgênicos , Microscopia de Fluorescência por Excitação Multifotônica , Neocórtex/patologia , Opsinas/genética , Opsinas/metabolismo , Células Piramidais/metabolismo
16.
Neuron ; 98(6): 1099-1115.e8, 2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-29887338

RESUMO

Perceptions, thoughts, and actions unfold over millisecond timescales, while learned behaviors can require many days to mature. While recent experimental advances enable large-scale and long-term neural recordings with high temporal fidelity, it remains a formidable challenge to extract unbiased and interpretable descriptions of how rapid single-trial circuit dynamics change slowly over many trials to mediate learning. We demonstrate a simple tensor component analysis (TCA) can meet this challenge by extracting three interconnected, low-dimensional descriptions of neural data: neuron factors, reflecting cell assemblies; temporal factors, reflecting rapid circuit dynamics mediating perceptions, thoughts, and actions within each trial; and trial factors, describing both long-term learning and trial-to-trial changes in cognitive state. We demonstrate the broad applicability of TCA by revealing insights into diverse datasets derived from artificial neural networks, large-scale calcium imaging of rodent prefrontal cortex during maze navigation, and multielectrode recordings of macaque motor cortex during brain machine interface learning.


Assuntos
Interfaces Cérebro-Computador , Córtex Motor/fisiologia , Redes Neurais de Computação , Córtex Pré-Frontal/fisiologia , Navegação Espacial/fisiologia , Aprendizado de Máquina não Supervisionado , Animais , Macaca mulatta , Camundongos , Análise de Componente Principal , Fatores de Tempo
17.
Nature ; 557(7704): 177-182, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29720658

RESUMO

Loss of dopamine in Parkinson's disease is hypothesized to impede movement by inducing hypo- and hyperactivity in striatal spiny projection neurons (SPNs) of the direct (dSPNs) and indirect (iSPNs) pathways in the basal ganglia, respectively. The opposite imbalance might underlie hyperkinetic abnormalities, such as dyskinesia caused by treatment of Parkinson's disease with the dopamine precursor L-DOPA. Here we monitored thousands of SPNs in behaving mice, before and after dopamine depletion and during L-DOPA-induced dyskinesia. Normally, intermingled clusters of dSPNs and iSPNs coactivated before movement. Dopamine depletion unbalanced SPN activity rates and disrupted the movement-encoding iSPN clusters. Matching their clinical efficacy, L-DOPA or agonism of the D2 dopamine receptor reversed these abnormalities more effectively than agonism of the D1 dopamine receptor. The opposite pathophysiology arose in L-DOPA-induced dyskinesia, during which iSPNs showed hypoactivity and dSPNs showed unclustered hyperactivity. Therefore, both the spatiotemporal profiles and rates of SPN activity appear crucial to striatal function, and next-generation treatments for basal ganglia disorders should target both facets of striatal activity.


Assuntos
Dopamina/metabolismo , Discinesias/patologia , Discinesias/fisiopatologia , Neurônios/metabolismo , Transtornos Parkinsonianos/patologia , Transtornos Parkinsonianos/fisiopatologia , Animais , Sinalização do Cálcio , Dopamina/deficiência , Discinesias/etiologia , Discinesias/metabolismo , Feminino , Levodopa/metabolismo , Levodopa/farmacologia , Masculino , Camundongos , Modelos Biológicos , Movimento/efeitos dos fármacos , Neostriado/metabolismo , Neostriado/patologia , Neostriado/fisiopatologia , Transtornos Parkinsonianos/metabolismo , Receptores de Dopamina D1/agonistas , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/agonistas , Receptores de Dopamina D2/metabolismo
18.
Nature ; 544(7648): 96-100, 2017 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-28321129

RESUMO

The human brain contains approximately 60 billion cerebellar granule cells, which outnumber all other brain neurons combined. Classical theories posit that a large, diverse population of granule cells allows for highly detailed representations of sensorimotor context, enabling downstream Purkinje cells to sense fine contextual changes. Although evidence suggests a role for the cerebellum in cognition, granule cells are known to encode only sensory and motor context. Here, using two-photon calcium imaging in behaving mice, we show that granule cells convey information about the expectation of reward. Mice initiated voluntary forelimb movements for delayed sugar-water reward. Some granule cells responded preferentially to reward or reward omission, whereas others selectively encoded reward anticipation. Reward responses were not restricted to forelimb movement, as a Pavlovian task evoked similar responses. Compared to predictable rewards, unexpected rewards elicited markedly different granule cell activity despite identical stimuli and licking responses. In both tasks, reward signals were widespread throughout multiple cerebellar lobules. Tracking the same granule cells over several days of learning revealed that cells with reward-anticipating responses emerged from those that responded at the start of learning to reward delivery, whereas reward-omission responses grew stronger as learning progressed. The discovery of predictive, non-sensorimotor encoding in granule cells is a major departure from the current understanding of these neurons and markedly enriches the contextual information available to postsynaptic Purkinje cells, with important implications for cognitive processing in the cerebellum.


Assuntos
Antecipação Psicológica/fisiologia , Cerebelo/citologia , Cerebelo/fisiologia , Aprendizagem/fisiologia , Neurônios/fisiologia , Recompensa , Animais , Comportamento Animal/fisiologia , Cálcio/análise , Cálcio/metabolismo , Cognição/fisiologia , Condicionamento Clássico/fisiologia , Condicionamento Operante/fisiologia , Feminino , Membro Anterior/fisiologia , Masculino , Camundongos , Imagem Molecular , Movimento , Células de Purkinje/fisiologia
19.
Cell Rep ; 17(12): 3385-3394, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-28009304

RESUMO

A major technological goal in neuroscience is to enable the interrogation of individual cells across the live brain. By creating a curved glass replacement to the dorsal cranium and surgical methods for its installation, we developed a chronic mouse preparation providing optical access to an estimated 800,000-1,100,000 individual neurons across the dorsal surface of neocortex. Post-surgical histological studies revealed comparable glial activation as in control mice. In behaving mice expressing a Ca2+ indicator in cortical pyramidal neurons, we performed Ca2+ imaging across neocortex using an epi-fluorescence macroscope and estimated that 25,000-50,000 individual neurons were accessible per mouse across multiple focal planes. Two-photon microscopy revealed dendritic morphologies throughout neocortex, allowed time-lapse imaging of individual cells, and yielded estimates of >1 million accessible neurons per mouse by serial tiling. This approach supports a variety of optical techniques and enables studies of cells across >30 neocortical areas in behaving mice.


Assuntos
Dendritos/ultraestrutura , Espinhas Dendríticas/ultraestrutura , Neocórtex/ultraestrutura , Células Piramidais/ultraestrutura , Animais , Cálcio/química , Camundongos , Microscopia de Fluorescência , Análise de Célula Única , Imagem com Lapso de Tempo
20.
Orphanet J Rare Dis ; 11(1): 68, 2016 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-27207271

RESUMO

BACKGROUND: Health Canada has defined rare diseases as life-threatening, seriously debilitating, or serious chronic conditions affecting a very small number of patients (~1 in 2,000 persons). An estimated 9 % of Canadians suffer from a rare disease. Drugs treating rare diseases (DRDs) are also known as orphan drugs. While Canada is currently developing an orphan drug framework, in the United States (US), the Orphan Drug Act (ODA) of 1983 established incentives for the development of orphan drugs. This study measured total annual expenditure of orphan drugs in Canada (2007-13) and estimated future (2014-18) orphan drug expenditure. METHODS: Orphan drugs approved by the US Food and Drug Administration (FDA) in the US were used as a proxy for the orphan drug landscape in Canada. Branded, orphan drugs approved by the FDA between 1983 through 2013 were identified (N = 356 unique products). Only US orphan drugs with the same orphan indication(s) approved in Canada were included in the analysis. Adjustment via an indication factoring was applied to products with both orphan and non-orphan indications using available data sources to isolate orphan-indication sales. The IMS Health MIDAS database of audited biopharmaceutical sales was utilized to measure total orphan drug expenditure, calculated annually from 2007-2013 and evaluated as a proportion of total annual pharmaceutical drug expenditure (adjusted to 2014 CAD). RESULTS: Between 2007 and 2013, expenditure was measured for a final N = 147 orphan drugs. Orphan drug expenditure totaled $610.2 million (M) in 2007 and $1,100.0 M in 2013, representing 3.3- 5.6 % of total Canadian pharmaceutical drug expenditure in 2007-2013, respectively. Future trend analysis suggests orphan drug expenditure will remain under 6 % of total expenditure in 2014-18. CONCLUSIONS: While the number of available orphan drugs and associated expenditure increased over time, access remains an issue, and from the perspectives of society and equity, overall spending on orphan drugs is lower relative to the number of patients affected with an orphan disease in Canada. The overall budget impact of orphan drugs is small and fairly stable relative to total pharmaceutical expenditure. Concerns that growth in orphan drug expenditure may lead to unsustainable drug expenditure do not appear to be justified.


Assuntos
Gastos em Saúde/estatística & dados numéricos , Produção de Droga sem Interesse Comercial/economia , Doenças Raras/economia , Canadá , Humanos , Doenças Raras/tratamento farmacológico
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