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1.
Res Sq ; 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37693580

RESUMEN

MR1 is a ubiquitously expressed MHC-Ib molecule that presents microbial metabolites to MR1-restricted T cells, but there are differences in the antigen presentation pathway of an intracellular microbe compared to exogenous antigen. We have shown the importance of endosomal trafficking proteins in MR1-dependent presentation of Mycobacterium tuberculosis (Mtb). Two pore channels (TPCs) are endosomal calcium channels that regulate endosomal trafficking. Due to their location on endosomes, we hypothesized that TPCs could be required for MR1-dependent presentation of antigens derived from the intracellular microbe Mtb. We found that TPCs are critical for the presentation of Mtb by MR1; inhibition of TPCs had no effect on MR1 presentation of extracellular (exogenous) antigens, HLA-B presentation, or HLA-II presentation. Finally, we found that the calcium sensitive trafficking protein Synaptotagmin 7 was also key in the presentation of Mtb by MR1. This calcium-dependent endosomal pathway is a novel mechanism by which the immune system can sample intracellular antigens.

2.
Commun Biol ; 6(1): 584, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-37258700

RESUMEN

The hippocampus and entorhinal cortex are deeply involved in learning and memory. However, little is known how ongoing events are processed in the hippocampal-entorhinal circuit. By recording from head-fixed rats during action-reward learning, here we show that the action and reward events are represented differently in the hippocampal CA1 region and lateral entorhinal cortex (LEC). Although diverse task-related activities developed after learning in both CA1 and LEC, phasic activities related to action and reward events differed in the timing of behavioral event representation. CA1 represented action and reward events almost instantaneously, whereas the superficial and deep layers of the LEC showed a delayed representation of the same events. Interestingly, we also found that ramping activity towards spontaneous action was correlated with waiting time in both regions and exceeded that in the motor cortex. Such functional activities observed in the entorhinal-hippocampal circuits may play a crucial role for animals in utilizing ongoing information to dynamically optimize their behaviors.


Asunto(s)
Región CA1 Hipocampal , Corteza Entorrinal , Ratas , Animales , Hipocampo , Aprendizaje
3.
Commun Biol ; 5(1): 942, 2022 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-36085311

RESUMEN

Mucosal-associated Invariant T (MAIT) cells are an innate-like T cell subset that recognize a broad array of microbial pathogens, including respiratory pathogens. Here we investigate the transcriptional profile of MAIT cells localized to the human lung, and postulate that MAIT cells may play a role in maintaining homeostasis at this mucosal barrier. Using the MR1/5-OP-RU tetramer, we identified MAIT cells and non-MAIT CD8+ T cells in lung tissue not suitable for transplant from human donors. We used RNA-sequencing of MAIT cells compared to non-MAIT CD8+ T cells to define the transcriptome of MAIT cells in the human lung. We show that, as a population, lung MAIT cells are polycytotoxic, secrete the directly antimicrobial molecule IL-26, express genes associated with persistence, and selectively express cytokine and chemokine- related molecules distinct from other lung-resident CD8+ T cells, such as interferon-γ- and IL-12- receptors. These data highlight MAIT cells' predisposition to rapid pro-inflammatory cytokine responsiveness and antimicrobial mechanisms in human lung tissue, concordant with findings of blood-derived counterparts, and support a function for MAIT cells as early sensors in the defense of respiratory barrier function.


Asunto(s)
Antiinfecciosos , Células T Invariantes Asociadas a Mucosa , Antibacterianos , Linfocitos T CD8-positivos , Citocinas , Humanos , Pulmón
4.
J Shoulder Elbow Surg ; 31(7): 1335-1343, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35167914

RESUMEN

BACKGROUND: Posterior shoulder capsule tightness is one of the factors for shoulder injuries in overhead athletes. Recent studies have shown the posterior capsule of the dominant arm to be stiffer than that of the nondominant arm in baseball players. However, whether posterior capsule tightness in the dominant arm is exclusive to overhead athletes remains unknown. This study aimed to investigate whether the posterior shoulder capsule of the dominant arm in baseball players is stiffer than that in nonthrowing population. METHODS: Fifteen male collegiate asymptomatic baseball players (baseball-player group) and fifteen male college students who did not partake in overhead sports (nonthrowing group) participated in this study. We measured the shear moduli of the middle and inferior posterior capsules, superior infraspinatus, inferior infraspinatus, teres minor, and posterior deltoid in the dominant arm by ultrasound shear wave elastography. We compared shear moduli between the two groups using an independent samples t-test and Mann-Whitney test. In addition, we investigated the correlation between the range of glenohumeral internal rotation and each shear modulus in each group using the Pearson correlation coefficient. RESULTS: The shear moduli in the baseball-player group were significantly higher than those in the nonthrowing group in both the middle posterior capsule (baseball-player group: 36.1 ± 5.6 kPa vs. nonthrowing group: 29.0 ± 8.6 kPa; P = .018) and inferior posterior capsule (37.1 ± 9.6 kPa vs. 27.9 ± 6.8 kPa; P = .002). However, no difference in the shear moduli of individual muscle groups was identified. The glenohumeral internal rotation range exhibited a statistically significant negative correlation with the shear modulus of the inferior posterior capsule in the baseball-player group (Pearson correlation coefficient = -0.586, P = .022). CONCLUSION: Our findings suggest that the posterior shoulder capsule of the dominant arm in baseball players is stiffer than that in nonthrowing population.


Asunto(s)
Béisbol , Rango del Movimiento Articular , Articulación del Hombro , Brazo , Béisbol/lesiones , Humanos , Masculino , Rango del Movimiento Articular/fisiología , Hombro/fisiología , Articulación del Hombro/diagnóstico por imagen , Articulación del Hombro/fisiología
5.
Vaccine ; 39(50): 7295-7299, 2021 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-34740474

RESUMEN

Donor Unrestricted T Cells (DURTs) are characterized by their use of antigen presentation molecules that are often invariant. As these cells recognize diverse mycobacterial antigens, often found in BCG, these cells have the potential to either serve as targets for vaccination, or as a means to enable the induction of traditional T and B cell immunity. Here, we will review specific DURT family members, and their relationship to BCG.


Asunto(s)
Inmunidad Adaptativa , Linfocitos T , Presentación de Antígeno , Humanos , Inmunidad Innata , Recuento de Linfocitos , Donantes de Tejidos
6.
Nature ; 598(7880): 321-326, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34552245

RESUMEN

Mounting evidence shows that dopamine in the striatum is critically involved in reward-based reinforcement learning1,2. However, it remains unclear how dopamine reward signals influence the entorhinal-hippocampal circuit, another brain network that is crucial for learning and memory3-5. Here, using cell-type-specific electrophysiological recording6, we show that dopamine signals from the ventral tegmental area and substantia nigra control the encoding of cue-reward association rules in layer 2a fan cells of the lateral entorhinal cortex (LEC). When mice learned novel olfactory cue-reward associations using a pre-learned association rule, spike representations of LEC fan cells grouped newly learned rewarded cues with a pre-learned rewarded cue, but separated them from a pre-learned unrewarded cue. Optogenetic inhibition of fan cells impaired the learning of new associations while sparing the retrieval of pre-learned memory. Using fibre photometry, we found that dopamine sends novelty-induced reward expectation signals to the LEC. Inhibition of LEC dopamine signals disrupted the associative encoding of fan cells and impaired learning performance. These results suggest that LEC fan cells represent a cognitive map of abstract task rules, and that LEC dopamine facilitates the incorporation of new memories into this map.


Asunto(s)
Dopamina/metabolismo , Corteza Entorrinal/citología , Corteza Entorrinal/fisiología , Memoria/fisiología , Animales , Anticipación Psicológica , Señales (Psicología) , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Células Piramidales/metabolismo , Recompensa
7.
Neurobiol Learn Mem ; 183: 107484, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34175450

RESUMEN

Retrieval deficit of long-term memory is a cardinal symptom of dementia and has been proposed to associate with abnormalities in the central cholinergic system. Difficulty in the retrieval of memory is experienced by healthy individuals and not limited to patients with neurological disorders that result in forgetfulness. The difficulty of retrieving memories is associated with various factors, such as how often the event was experienced or remembered, but it is unclear how the cholinergic system plays a role in the retrieval of memory formed by a daily routine (accumulated experience). To investigate this point, we trained rats moderately (for a week) or extensively (for a month) to detect a visual cue in a two-alternative forced-choice task. First, we confirmed the well-established memory in the extensively trained group was more resistant to the retrieval problem than recently acquired memory in the moderately trained group. Next, we tested the effect of a cholinesterase inhibitor, donepezil, on the retrieval of memory after a long no-task period in extensively trained rats. Pre-administration of donepezil improved performance and reduced the latency of task initiation compared to the saline-treated group. Finally, we lesioned cholinergic neurons of the nucleus basalis magnocellularis (NBM), which project to the entire neocortex, by injecting the cholinergic toxin 192 IgG-saporin. NBM-lesioned rats showed severely impaired task initiation and performance. These abilities recovered as the trials progressed, though they never reached the level observed in rats with intact NBM. These results suggest that acetylcholine released from the NBM contributes to the retrieval of well-established memory developed by a daily routine.


Asunto(s)
Acetilcolina/metabolismo , Núcleo Basal de Meynert/fisiología , Neuronas Colinérgicas/fisiología , Recuerdo Mental/fisiología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Animales , Anticuerpos Monoclonales/farmacología , Núcleo Basal de Meynert/efectos de los fármacos , Núcleo Basal de Meynert/metabolismo , Colinérgicos/farmacología , Neuronas Colinérgicas/efectos de los fármacos , Neuronas Colinérgicas/metabolismo , Inhibidores de la Colinesterasa/farmacología , Donepezilo/farmacología , Recuerdo Mental/efectos de los fármacos , Neocórtex/efectos de los fármacos , Neocórtex/metabolismo , Neocórtex/fisiología , Ratas , Saporinas/farmacología
9.
J Neurophysiol ; 124(6): 1923-1941, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33085554

RESUMEN

Standard analysis of neuronal functions assesses the temporal correlation between animal behaviors and neuronal activity by aligning spike trains with the timing of a specific behavioral event, e.g., visual cue. However, spike activity is often involved in information processing dependent on a relative phase between two consecutive events rather than a single event. Nevertheless, less attention has so far been paid to such temporal features of spike activity in relation to two behavioral events. Here, we propose "Phase-Scaling analysis" to simultaneously evaluate the phase locking and scaling to the interval between two events in task-related spike activity of individual neurons. This analysis method can discriminate conceptual "scaled"-type neurons from "nonscaled"-type neurons using an activity variation map that combines phase locking with scaling to the interval. Its robustness was validated by spike simulation using different spike properties. Furthermore, we applied it to analyzing actual spike data from task-related neurons in the primary visual cortex (V1), posterior parietal cortex (PPC), primary motor cortex (M1), and secondary motor cortex (M2) of behaving rats. After hierarchical clustering of all neurons using their activity variation maps, we divided them objectively into four clusters corresponding to nonscaled-type sensory and motor neurons and scaled-type neurons including sustained and ramping activities, etc. Cluster/subcluster compositions for V1 differed from those of PPC, M1, and M2. The V1 neurons showed the fastest functional activities among those areas. Our method was also applicable to determine temporal "forms" and the latency of spike activity changes. These findings demonstrate its utility for characterizing neurons.NEW & NOTEWORTHY Phase-Scaling analysis is a novel technique to unbiasedly characterize the temporal dependency of functional neuron activity on two behavioral events and objectively determine the latency and form of the activity change. This powerful analysis can uncover several classes of latently functioning neurons that have thus far been overlooked, which may participate differently in intermediate processes of a brain function. The Phase-Scaling analysis will yield profound insights into neural mechanisms for processing internal information.


Asunto(s)
Potenciales de Acción/fisiología , Conducta Animal/fisiología , Corteza Cerebral/fisiología , Neuronas/fisiología , Animales , Electrocorticografía , Masculino , Modelos Teóricos , Ratas Long-Evans , Factores de Tiempo
10.
J Immunol ; 205(11): 3023-3036, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33097574

RESUMEN

Recently, the efficacy of Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccination is being reassessed in accordance with the achievements of clinical tuberculosis (TB) vaccine research. However, the mechanisms ultimately determining the success or failure of BCG vaccination to prevent pulmonary TB remain poorly understood. In this study, we analyzed the protective effects of intradermal BCG vaccination by using specific pathogen-free cynomolgus macaques of Asian origin that were intradermally vaccinated with BCG (Tokyo strain) followed by Mycobacterium tuberculosis (Erdman strain) infection. Intradermal BCG administration generated TB Ag-specific multifunctional CD4 T cell responses in peripheral blood and bronchoalveolar lavage and almost completely protected against the development of TB pathogenesis with aggravation of clinical parameters and high levels of bacterial burdens in extrapulmonary organs. However, interestingly, there were no differences in bacterial quantitation and pathology of extensive granulomas in the lungs between BCG-vaccinated monkeys and control animals. These results indicated that the changes in clinical parameters, immunological responses, and quantitative gross pathology that are used routinely to determine the efficacy of TB vaccines in nonhuman primate models might not correlate with the bacterial burden and histopathological score in the lung as measured in this study.


Asunto(s)
Vacuna BCG/inmunología , Vacunas contra la Tuberculosis/inmunología , Tuberculosis/inmunología , Animales , Antígenos Bacterianos/inmunología , Lavado Broncoalveolar/métodos , Linfocitos T CD4-Positivos/inmunología , Pulmón/inmunología , Macaca fascicularis , Mycobacterium bovis/inmunología , Mycobacterium tuberculosis/inmunología , Neumonía/inmunología , Vacunación/métodos
11.
Neuron ; 107(6): 1095-1112.e6, 2020 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-32697942

RESUMEN

Patients with Alzheimer's disease (AD) suffer from spatial memory impairment and wandering behavior, but the brain circuit mechanisms causing such symptoms remain largely unclear. In healthy brains, spatially tuned hippocampal place cells and entorhinal grid cells exhibit distinct spike patterns in different environments, a circuit function called "remapping." We tested remapping in amyloid precursor protein knockin (APP-KI) mice with impaired spatial memory. CA1 neurons, including place cells, showed disrupted remapping, although their spatial tuning was only mildly diminished. Medial entorhinal cortex (MEC) neurons severely lost their spatial tuning and grid cells were almost absent. Fast gamma oscillatory coupling between the MEC and CA1 was also impaired. Mild disruption of MEC grid cells emerged in younger APP-KI mice, although the spatial memory and CA1 remapping of the animals remained intact. These results point to remapping impairment in the hippocampus, possibly linked to grid cell disruption, as circuit mechanisms underlying spatial memory impairment in AD.


Asunto(s)
Enfermedad de Alzheimer/fisiopatología , Región CA1 Hipocampal/fisiopatología , Conectoma , Corteza Entorrinal/fisiopatología , Neuronas/clasificación , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Precursor de Proteína beta-Amiloide/genética , Animales , Región CA1 Hipocampal/patología , Corteza Entorrinal/patología , Femenino , Ritmo Gamma , Masculino , Ratones , Ratones Endogámicos C57BL , Vías Nerviosas/patología , Vías Nerviosas/fisiopatología , Neuronas/patología , Neuronas/fisiología
12.
Parasitol Int ; 76: 102096, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32114084

RESUMEN

In the present study, we demonstrate that the Japanese macaque (Macaca fuscata) can be used as an effective alternative in vivo model for investigating hypnozoite-induced relapsing infection caused by Plasmodium cynomolgi B strain, and that this model is comparable to the rhesus macaque model. Two female Japanese macaques (JM-1 and JM-2; aged 5 years; weighing about 4.0 kg) were used for the experiment. To produce sporozoites in mosquitoes, blood infected with P. cynomolgi B strain was collected from the donor monkey JM-1 and fed to approximately 200 mosquitoes using the standard artificial membrane feeding method. The isolated sporozoites (2 × 105) were intravenously inoculated into the JM-2 monkey, and the blood stage of the parasite was detected on day 8 after the infection. Chloroquine sulfate (CQ) was intramuscularly administered at a dosage of 6.0 mg/kg into the JM-2 monkey for 6 consecutive days from day 12 onward, after which the parasites disappeared from the peripheral blood. The first relapse occurred on day 26, which was treated again with CQ. Then, the second relapse occurred on day 44, which was cured by CQ treatment followed by the administration of primaquine phosphate (PQ) at a dosage of 1.0 mg/kg/day for 15 days. The JM-2 monkey was observed until 69 days after PQ administration, and there was no relapse during the entire follow-up period. We propose that the Japanese macaque model could contribute not only to drug screening for anti-hypnozoite activity, but could also be used as a powerful tool for investigating hypnozoite biology.


Asunto(s)
Modelos Animales de Enfermedad , Macaca fuscata , Malaria/parasitología , Plasmodium cynomolgi/fisiología , Animales , Femenino , Recurrencia
13.
eNeuro ; 6(4)2019.
Artículo en Inglés | MEDLINE | ID: mdl-31235466

RESUMEN

In the parkinsonian state, the motor cortex and basal ganglia (BG) undergo dynamic remodeling of movement representation. One such change is the loss of the normal contralateral lateralized activity pattern. The increase in the number of movement-related neurons responding to ipsilateral or bilateral limb movements may cause motor problems, including impaired balance, reduced bimanual coordination, and abnormal mirror movements. However, it remains unknown how individual types of motor cortical neurons organize this reconstruction. To explore the effect of dopamine depletion on lateralized activity in the parkinsonian state, we used a partial hemiparkinsonian model [6-hydroxydopamine (6-OHDA) lesion] in Long-Evans rats performing unilateral movements in a right-left pedal task, while recording from primary (M1) and secondary motor cortex (M2). The lesion decreased contralateral preferred activity in both M1 and M2. In addition, this change differed among identified intratelencephalic (IT) and pyramidal tract (PT) cortical projection neurons, depending on the cortical area. We detected a decrease in lateralized activity only in PT neurons in M1, whereas in M2, this change was observed in IT neurons, with no change in the PT population. Our results suggest a differential effect of dopamine depletion in the lateralized activity of the motor cortex, and suggest possible compensatory changes in the contralateral hemisphere.


Asunto(s)
Lateralidad Funcional , Corteza Motora/fisiopatología , Movimiento , Neuronas/fisiología , Trastornos Parkinsonianos/fisiopatología , Animales , Modelos Animales de Enfermedad , Masculino , Vías Nerviosas/fisiopatología , Ratas Long-Evans
14.
J Immunol ; 203(1): 188-197, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31101668

RESUMEN

Suppressor of cytokine signaling 1 (SOCS1) plays a key role in the negative regulation of JAK/STAT signaling, which is involved in innate immunity and subsequent adaptive immunity. Bacillus Calmette-Guérin (BCG) induces upregulation of SOCS1 expression in host cells, which may lead to the suppression of immune responses by BCG via inhibition of the JAK/STAT signaling pathway. This might cause A reduction in the protective effect of a BCG vaccine. In the current study, we assessed the immune responses to and the protective efficacy of a recombinant BCG secreting a dominant negative mutant of the SOCS1 molecule (rBCG-SOCS1DN). C57BL/6 mice were immunized with rBCG-SOCS1DN or parental BCG Tokyo vaccine strain harboring an empty plasmid vector (rBCG-pSO). rBCG-SOCS1DN enhanced the activation of bone marrow-derived dendritic cells and the activation of T cells compared with those with rBCG-pSO. The amounts of IFN-γ, TNF-α, and IL-6 produced by splenocytes of rBCG-SOCS1DN-immunized mice were larger than those produced by splenocytes of rBCG-pSO-immunized mice. Moreover, the rBCG-SOCS1DN-immunized mice showed a substantial reduction in the number of CFU of Mycobacterium tuberculosis in the lungs and spleens compared with that in control BCG-immunized mice when the immunized mice were infected with a highly pathogenic M. tuberculosis strain by inhalation. These findings provide evidence for the possibility of rBCG-SOCS1DN being an effective M. tuberculosis vaccine with a novel concept of rBCG as a tool for immunomodulation in host cells.


Asunto(s)
Vacuna BCG/inmunología , Células Dendríticas/inmunología , Mutación/genética , Mycobacterium tuberculosis/fisiología , Proteína 1 Supresora de la Señalización de Citocinas/genética , Linfocitos T/inmunología , Tuberculosis/inmunología , Animales , Vacuna BCG/genética , Recuento de Colonia Microbiana , Citocinas/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Inmunización , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Células RAW 264.7 , Transducción de Señal , Proteína 1 Supresora de la Señalización de Citocinas/antagonistas & inhibidores , Tuberculosis/prevención & control , Vacunas Sintéticas/genética
15.
Cell Biol Int ; 43(11): 1296-1306, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30958611

RESUMEN

Light is an indispensable part of routine laboratory work in which conventional light is generally used. Light-emitting diodes (LEDs) have come to replace conventional light, and thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from the African green monkey kidney, we assessed the possible consequences of the blue spectra of LED light in future animal experiments and proposed a potent mitigation against light-induced damage. COS-7 cells were exposed to blue LED light (450 nm) and the growth and deoxyribonucleic acid (DNA) damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as the light exposure time was prolonged. Reactive oxygen species (ROS) generation was also elevated in accordance to the extension of light exposure time. A comparison with dark-maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time-dependent manner. In turn, antioxidant treatment has been shown to improve cell growth and viability under blue LED light conditions. This indicates that antioxidants have potential against blue LED light-induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and maximize the beneficial use of LED light in future animal experiments.


Asunto(s)
Antioxidantes/farmacología , Procesos de Crecimiento Celular/fisiología , Daño del ADN/fisiología , Especies Reactivas de Oxígeno/metabolismo , Animales , Células COS , Muerte Celular/fisiología , Supervivencia Celular/fisiología , Chlorocebus aethiops , Luz
16.
J Neurosci ; 39(3): 485-502, 2019 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-30478035

RESUMEN

It is well known that the posterior parietal cortex (PPC) and frontal motor cortices in primates preferentially control voluntary movements of contralateral limbs. The PPC of rats has been defined based on patterns of thalamic and cortical connectivity. The anatomical characteristics of this area suggest that it may be homologous to the PPC of primates. However, its functional roles in voluntary forelimb movements have not been well understood, particularly in the lateralization of motor limb representation; that is, the limb-specific activity representations for right and left forelimb movements. We examined functional spike activity of the PPC and two motor cortices, the primary motor cortex (M1) and the secondary motor cortex (M2), when head-fixed male rats performed right or left unilateral movements. Unlike primates, PPC neurons in rodents were found to preferentially represent ipsilateral forelimb movements, in contrast to the contralateral preference of M1 and M2 neurons. Consistent with these observations, optogenetic activation of PPC and motor cortices, respectively, evoked ipsilaterally and contralaterally biased forelimb movements. Finally, we examined the effects of optogenetic manipulation on task performance. PPC or M1 inhibition by optogenetic GABA release shifted the behavioral limb preference contralaterally or ipsilaterally, respectively. In addition, weak optogenetic PPC activation, which was insufficient to evoke motor responses by itself, shifted the preference ipsilaterally; although similar M1 activation showed no effects on task performance. These paradoxical observations suggest that the PPC plays evolutionarily different roles in forelimb control between primates and rodents.SIGNIFICANCE STATEMENT In rodents, the primary and secondary motor cortices (M1 and M2, respectively) are involved in voluntary movements with contralateral preference. However, it remains unclear whether and how the posterior parietal cortex (PPC) participates in controlling multiple limb movements. We recorded functional activity from these areas using a behavioral task to monitor movements of the right and left forelimbs separately. PPC neurons preferentially represented ipsilateral forelimb movements and optogenetic PPC activation evoked ipsilaterally biased forelimb movements. Optogenetic PPC inhibition via GABA release shifted the behavioral limb preference contralaterally during task performance, whereas weak optogenetic PPC activation, which was insufficient to evoke motor responses by itself, shifted the preference ipsilaterally. Our findings suggest rodent PPC contributes to ipsilaterally biased motor response and/or planning.


Asunto(s)
Miembro Anterior/fisiología , Lateralidad Funcional/fisiología , Movimiento/fisiología , Lóbulo Parietal/fisiología , Animales , Channelrhodopsins/genética , Channelrhodopsins/fisiología , Condicionamiento Operante , Electromiografía , Masculino , Corteza Motora/fisiología , Optogenética , Técnicas de Placa-Clamp , Desempeño Psicomotor/fisiología , Ratas , Ratas Transgénicas , Ácido gamma-Aminobutírico/metabolismo , Ácido gamma-Aminobutírico/fisiología
17.
Behav Processes ; 157: 291-300, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30366108

RESUMEN

As training progresses, animals show a transition from goal-dependent behavior to goal-independent behavior (habitual responses). Habit formation is influenced by several factors, including the amount of training and action-outcome contingency. However, it remains unknown whether and how discretion for behavioral selection influences habit formation. To this end, we trained male rats in two types of two-alternative forced-choice task: visual association and nonvisual association tasks. In the first type of task, rats learned the association between reward and a visual cue, the position of which was randomly changed per trial so that rats had to make a judgmental decision about which choice delivered the reward in each trial (discreet judgment group); in the second type of task, the rats learned that a reward was delivered after either choice following task initiation (uncontrolled judgment group). To test the sensitivity to contingency manipulation, the extinction tests were conducted in short- and long-term trained groups, with the result that the overtrained rats in the uncontrolled judgment group, but not the other three groups, showed less sensitivity. To further investigate the reward sensitivity in the long-term trained groups from another perspective, we continuously and periodically altered the reward size for each trial. The rats of the discreet judgment group changed intertrial intervals depending on reward size, while this tendency was weaker in the uncontrolled judgment group. These results suggest that discreet judgment maintained goal-directed rat behavior, whereas uncontrolled judgment led to the development of habit-like behavior.


Asunto(s)
Asociación , Conducta Animal/fisiología , Conducta de Elección/fisiología , Hábitos , Recompensa , Animales , Masculino , Ratas , Ratas Long-Evans
18.
Infect Immun ; 86(11)2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30181351

RESUMEN

Suppressor of cytokine signaling 1 (SOCS1) is a negative regulator of JAK/STAT signaling and is induced by mycobacterial infection. To understand the major function of SOCS1 during infection, we established a novel system in which recombinant Mycobacterium bovis bacillus Calmette-Guérin expressed dominant-negative SOCS1 (rBCG-SOCS1DN) because it would not affect the function of SOCS1 in uninfected cells. When C57BL/6 mice and RAG1-/- mice were intratracheally inoculated with rBCG-SOCS1DN, the amount of rBCG-SOCS1DN in the lungs was significantly reduced compared to that in the lungs of mice inoculated with a vector control counterpart and wild-type BCG. However, these significant differences were not observed in NOS2-/- mice and RAG1-/- NOS2-/- double-knockout mice. These findings demonstrated that SOCS1 inhibits nitric oxide (NO) production to establish mycobacterial infection and that rBCG-SOCS1DN has the potential to be a powerful tool for studying the primary function of SOCS1 in mycobacterial infection.


Asunto(s)
Interacciones Huésped-Patógeno , Mycobacterium bovis/crecimiento & desarrollo , Transducción de Señal , Proteína 1 Supresora de la Señalización de Citocinas/metabolismo , Tuberculosis/microbiología , Tuberculosis/patología , Animales , Modelos Animales de Enfermedad , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/deficiencia , Óxido Nítrico Sintasa de Tipo II/metabolismo , Proteína 1 Supresora de la Señalización de Citocinas/genética
19.
Neuroscience ; 388: 297-316, 2018 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-30077617

RESUMEN

Animals can suppress their behavioral response in advance according to changes in environmental context (proactive inhibition: delaying the start of response), a process in which several cortical areas may participate. However, it remains unclear how this process is adaptively regulated according to contextual changes on different timescales. To address the issue, we used an improved stop-signal task paradigm to behaviorally and electrophysiologically characterize the temporal aspect of proactive inhibition in head-fixed rats. In the task, they must respond to a go cue as quickly as possible (go trial), but did not have to respond if a stop cue followed the go cue (stop trial). The task alternated between a block of only go trials (G-block) and a block of go-and-stop trials (GS-block). We observed block-based and trial-based proactive inhibition (emerging in GS-block and after stop trial, respectively) by behaviorally evaluating the delay in reaction time in correct go trials depending on contextual changes on different timescales. We electrophysiologically analyzed task-related neuronal activity in the primary and secondary motor, posterior parietal, and orbitofrontal cortices (M1, M2, PPC, and OFC, respectively). Under block-based proactive inhibition, spike activity of cue-preferring OFC neurons was attenuated continuously, while M1 and M2 activity was enhanced during motor preparation. Subsequently, M1 activity was attenuated during motor decision/execution. Under trial-based proactive inhibition, the OFC activity was continuously enhanced, and PPC and M1 activity was also enhanced shortly during motor decision/execution. These results suggest that different cortical mechanisms underlie the two types of proactive inhibition in rodents.


Asunto(s)
Corteza Cerebral/fisiología , Neuronas/fisiología , Inhibición Proactiva , Potenciales de Acción , Animales , Mapeo Encefálico , Microelectrodos , Actividad Motora/fisiología , Ratas Long-Evans
20.
Neuron ; 99(6): 1302-1314.e5, 2018 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-30146299

RESUMEN

The basal ganglia play key roles in adaptive behaviors guided by reward and punishment. However, despite accumulating knowledge, few studies have tested how heterogeneous signals in the basal ganglia are organized and coordinated for goal-directed behavior. In this study, we investigated neuronal signals of the direct and indirect pathways of the basal ganglia as rats performed a lever push/pull task for a probabilistic reward. In the dorsomedial striatum, we found that optogenetically and electrophysiologically identified direct pathway neurons encoded reward outcomes, whereas indirect pathway neurons encoded no-reward outcome and next-action selection. Outcome coding occurred in association with the chosen action. In support of pathway-specific neuronal coding, light activation induced a bias on repeat selection of the same action in the direct pathway, but on switch selection in the indirect pathway. Our data reveal the mechanisms underlying monitoring and updating of action selection for goal-directed behavior through basal ganglia circuits.


Asunto(s)
Conducta Animal/fisiología , Cuerpo Estriado/fisiología , Objetivos , Vías Nerviosas/fisiología , Animales , Ganglios Basales/fisiología , Masculino , Neuronas/fisiología , Optogenética/métodos , Ratas Transgénicas , Recompensa
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