•Pseudotyped lentivectors with fusion glycoproteins enhance retrograde gene transfer.•The vectors have the advantage of functional manipulation of specific neural circuits.•Vector technology promotes ...the study of the mechanism underlying brain functions.•The technology offers a useful tool for gene therapy of neurological disorders.
A lentiviral vector strategy for efficient gene transfer through retrograde axonal transport provides a powerful approach for studying the neural circuit mechanisms that mediate higher level functions of the central nervous system. Pseudotyping of human immunodeficiency virus type-1 with different types of fusion glycoproteins (FuGs), which are composed of segments of rabies virus glycoprotein (RV-G) and vesicular stomatitis virus glycoprotein (VSV-G), enhances the efficiency of retrograde gene transfer in both rodent and non-human primate brains. These pseudotyped lentiviral vectors are classified into two groups, highly efficient retrograde gene transfer (HiRet) and neuron-specific retrograde gene transfer (NeuRet) vectors, based on their properties of gene transduction. Combinatorial use of the pseudotyped vectors with various molecular tools for manipulating neural circuit functions (such as the cell targeting, synaptic silencing, and optogenetic or chemogenetic approaches) enables us to control the function of specific neural circuits, thus leading to a deeper understanding of the mechanism underlying various nervous system functions.
P-type conversion of n−-GaN by Mg-ion implantation was successfully performed using high quality GaN epitaxial layers grown on free-standing low-dislocation-density GaN substrates. These samples ...showed low-temperature PL spectra quite similar to those observed from Mg-doped MOVPE-grown p-type GaN, consisting of Mg related donor–acceptor pair (DAP) and acceptor bound exciton (ABE) emission. P–n diodes fabricated by the Mg-ion implantation showed clear rectifying I–V characteristics and UV and blue light emissions were observed at forward biased conditions for the first time.
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.
•Firing of striatal direct and indirect pathway neurons changes at action selection•Action, outcomes, and next action are encoded in a pathway-specific manner•Outcome coding occurred in association with the chosen action•Activation of direct and indirect pathways biases toward repeat or switch, respectively
In rats performing reward-oriented action selection, we demonstrate that striatal direct pathway neurons encode chosen action-associated reward and indirect pathway neurons encode no-reward outcomes and next selection. Activation of direct or indirect pathways biases toward repeating or switching actions, respectively.
A 61-year-old woman was transferred with a complaint of a fever and productive cough. She had tested positive for Mycobacterium avium and Nocardia cyriacigeorgica at least twice, and Streptococcus ...pneumonia (PISP) was isolated (3+) from her purulent sputum. As radiological findings, a lower lung field-dominant infiltration shadow and nodular shadow with cavity were recognized in the bilateral lung fields. We diagnosed her with pneumococcal pneumonia co-infection with M. avium and N. cyriacigeorgica. She was treated with MEPM for pneumococcal pneumonia, a standard regimen containing clarithromycin for pulmonary M. avium complex (MAC) disease, and sulfamethoxazole/trimethoprim for pulmonary nocardiosis. She improved with appropriate treatment.
A prominent feature of neocortical pyramidal cells (PCs) is their numerous projections to diverse brain areas. In layer 5 (L5) of the rat frontal cortex, there are 2 major subtypes of PCs that differ ...in their long-range axonal projections, corticopontine (CPn) cells and crossed corticostriatal (CCS) cells. The outputs of these L5 PCs can be regulated by feedback inhibition from neighboring cortical GABAergic cells. Two major subtypes of GABAergic cells are parvalbumin (PV)-positive and somatostatin (SOM)-positive cells. PV cells have a fast-spiking (FS) firing pattern, while SOM cells have a low threshold spike (LTS) and regular spiking. In this study, we found that the 2 PC subtypes in L5 selectively make recurrent connections with LTS cells. The connection patterns correlated with the morphological and physiological diversity of LTS cells. LTS cells with high input resistance (Ri) exhibited more compact dendrites and more rebound spikes than LTS cells with low Ri, which had vertically elongated dendrites. LTS subgroups differently inhibited the PC subtypes, although FS cells made nonselective connections with both projection subtypes. These results demonstrate a novel recurrent network of inhibitory and projection-specific excitatory neurons within the neocortex.
Lymph node (LN) metastasis through the lymphatic network is a major route for cancer dissemination. Tumor cells reach the marginal sinuses of LNs via afferent lymphatic vessels (LVs) and form ...metastatic lesions that lead to distant metastasis. Thus, targeting of metastatic cells in the marginal sinuses could improve cancer treatment outcomes. Here, we investigated whether lymphatic administration of a drug combined with sonoporation could be used to treat a LN containing proliferating murine FM3A breast cancer cells, which are highly invasive, in its marginal sinus. First, we used contrast-enhanced high-frequency ultrasound and histopathology to analyze the structure of LVs in MXH10/Mo-lpr/lpr mice, which exhibit systemic lymphadenopathy. We found that contrast agent injected into the subiliac LN flowed into the marginal sinus of the proper axillary LN (PALN) and reached the cortex. Next, we examined the anti-tumor effects of our proposed technique. We found that a strong anti-tumor effect was achieved by lymphatic administration of doxorubicin and sonoporation. Furthermore, our proposed method prevented tumor cells in the marginal sinus from invading the parenchyma of the PALN and resulted in tumor necrosis. We conclude that lymphatic administration of a drug combined with sonoporation could exert a curative effect in LNs containing metastatic cells in their marginal sinuses.
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•We optimize the junction of segments that constitute fusion glycoproteins for neuron-specific retrograde gene transfer.•A novel type of fusion glycoprotein (type E) produces the most ...efficient retrograde gene transfer of lentiviral vectors.•The pseudotyped vector transduces selectively neuronal cells around the injection site.
The vector for neuron-specific retrograde gene transfer (NeuRet) is a pseudotype of human immunodeficiency virus type 1 (HIV-1)-based vector with fusion glycoprotein type C (FuG-C), which consists of the N-terminal region of the extracellular domain of rabies virus glycoprotein (RVG) and the membrane-proximal region of the extracellular domain and the transmembrane/cytoplasmic domains of vesicular stomatitis virus glycoprotein (VSVG). The NeuRet vector shows a high efficiency of gene transfer through retrograde axonal transport and transduces selectively neuronal cells around the injection site.
We aimed to improve the efficiency of retrograde gene transfer of the NeuRet vector by optimizing the junction of RVG and VSVG segments in fusion glycoproteins in their membrane-proximal region.
We produced various types of fusion glycoproteins, in which the junction of the two glycoprotein segments diverged in the membrane-proximal region and used for pseudotyping of HIV-1-based vector to evaluate the in vivo gene transfer efficiency after intrastriatal injection. We found a novel type of fusion glycoprotein termed type E (FuG-E) that yielded enhanced efficiency of retrograde gene delivery, showing neuron-specific transduction surrounding the injection site.
The NeuRet vector pseudotyped with FuG-E displayed the improved efficiency of retrograde gene transfer into different neural pathways compared with the original vector pseudotyped with FuG-C.
Our vector system with FuG-E provides a powerful tool for gene therapeutic trials of neurological and neurodegenerative diseases and for the study of the mechanisms of neural networks underlying various brain functions.
It is generally accepted that the direct connection from the motor cortex to spinal motor neurons is responsible for dexterous hand movements in primates. However, the role of the 'phylogenetically ...older' indirect pathways from the motor cortex to motor neurons, mediated by spinal interneurons, remains elusive. Here we used a novel double-infection technique to interrupt the transmission through the propriospinal neurons (PNs), which act as a relay of the indirect pathway in macaque monkeys (Macaca fuscata and Macaca mulatta). The PNs were double infected by injection of a highly efficient retrograde gene-transfer vector into their target area and subsequent injection of adeno-associated viral vector at the location of cell somata. This method enabled reversible expression of green fluorescent protein (GFP)-tagged tetanus neurotoxin, thereby permitting the selective and temporal blockade of the motor cortex–PN–motor neuron pathway. This treatment impaired reach and grasp movements, revealing a critical role for the PN-mediated pathway in the control of hand dexterity. Anti-GFP immunohistochemistry visualized the cell bodies and axonal trajectories of the blocked PNs, which confirmed their anatomical connection to motor neurons. This pathway-selective and reversible technique for blocking neural transmission does not depend on cell-specific promoters or transgenic techniques, and is a new and powerful tool for functional dissection in system-level neuroscience studies.
The ability to infer others’ mental states is essential to social interactions. This ability, critically evaluated by testing whether one attributes false beliefs (FBs) to others, has been considered ...to be uniquely hominid and to accompany the activation of a distributed brain network. We challenge the taxon specificity of this ability and identify the causal brain locus by introducing an anticipatory-looking FB paradigm combined with chemogenetic neuronal manipulation in macaque monkeys. We find spontaneous gaze bias of macaques implicitly anticipating others’ FB-driven actions. Silencing of the medial prefrontal neuronal activity with inhibitory designer receptor exclusively activated by designer drugs (DREADDs) specifically eliminates the implicit gaze bias while leaving the animals’ visually guided and memory-guided tracking abilities intact. Thus, neuronal activity in the medial prefrontal cortex could have a causal role in FB-attribution-like behaviors in the primate lineage, emphasizing the importance of probing the neuronal mechanisms underlying theory of mind with relevant macaque animal models.
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•Macaques exhibit implicit gaze bias anticipating others’ false-belief-driven actions•Inhibitory DREADDs silencing medial prefrontal neurons abolish the gaze bias•Macaques and humans share brain networks for false-belief attribution-like behaviors•Among the network, the medial prefrontal cortex is causally linked to mental attribution
Hayashi et al. ask whether only hominids possess theory of mind. They show macaques’ implicit gaze bias anticipating others’ false-belief-guided actions, which is abolished by chemogenetic silencing of the medial prefrontal cortex. Thus, false-belief attribution-like behaviors of non-human primates are underpinned by shared neuronal mechanisms with humans.
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