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1.
An. psicol ; 37(3): 406-411, Oct-Dic. 2021. ilus
Artigo em Inglês | IBECS | ID: ibc-215123

RESUMO

This paper emphazises main steps of the discovery of one of the most salient autonomic markers of mind expressions, the electrodermal activity (EDA). The contribution of French and German schools of physiology, aimed by clinical needs and the desire to know further about physiological mechanisms, constitutes the very early roots of such activity. In this frame, Féré and Tarchanoff, respectively a French and a Russian discoverers, established the link between mind activity and the EDA on the one hand and laid the methodological foundations of modern utilisation of this neuromarker on the other hand. This heritage, associated with central neural measures, is promised to an expanding future in neuropsychology, psychopathology, neurology, criminology and in cognitive and affective neuroscience.(AU)


Este artículo enfatiza las etapas principales del descubrimiento de uno de los marcadores autonómos más destacados de las expresiones mentales, la actividad electrodérmica (EDA). La contribución de las escuelas de fisiología francesa y alemana, orientada por las necesidades clínicas y el deseo de conocer más sobre los mecanismos fisiológicos, constituyen las primeras raíces de dicha actividad. En este marco, Féré y Tarchanoff, descubridores franceses y rusos respectivamente, establecieron el vínculo entre la actividad mental y la EDA, por un lado, y sentaron las bases metodológicas de la utilización moderna de este neuromarcador, por el otro. Este legado, asociado con medidas neuronales centrales, promete un futuro en expansión en neuropsicología, psicopatología, neurología, criminología y en neurociencia cognitiva y afectiva.(AU)


Assuntos
Humanos , Masculino , Feminino , Resposta Galvânica da Pele , Sistema Nervoso Autônomo , Emoções , Saúde Mental , Fisiologia , Marcadores do Trato Nervoso , Neuropsicologia , Psicopatologia , Neurologia , Neurociência Cognitiva , Psicologia , França , Alemanha
2.
Brain Res Bull ; 169: 184-195, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33508400

RESUMO

Itch is an annoying sensation that always triggers scratching behavior, yet little is known about its transmission pathway in the central nervous system. Parabrachial nucleus (PBN), an essential transmission nucleus in the brainstem, has been proved to be the first relay station in itch sensation. Meanwhile, dorsal midline/intralaminar thalamic complex (dMITC) is proved to be activated with nociceptive stimuli. However, whether the PBN-projecting neurons in spinal dorsal horn (SDH) send collateral projections to dMITC, and whether these projections involve in itch remain unknown. In the present study, a double retrograde tracing method was applied when the tetramethylrhodamine-dextran (TMR) was injected into the dMITC and Fluoro-gold (FG) was injected into the PBN, respectively. Immunofluorescent staining for NeuN, substance P receptor (SPR), substance P (SP), or FOS induced by itch or pain stimulations with TMR and FG were conducted to provide morphological evidence. The results revealed that TMR/FG double-labeled neurons could be predominately observed in superficial laminae and lateral spinal nucleus (LSN) of SDH; Meanwhile, most of the collateral projection neurons expressed SPR and some of them expressed FOS in acute itch model induced by histamine. The present results implicated that some of the SPR-expressing neurons in SDH send collateral projections to the dMITC and PBN in itch transmission, which might be involved in itch related complex affective/emotional processing to the higher brain centers.


Assuntos
Núcleos Parabraquiais/metabolismo , Células do Corno Posterior/metabolismo , Tálamo/metabolismo , Animais , Masculino , Camundongos , Vias Neurais/metabolismo , Marcadores do Trato Nervoso , Proteínas Proto-Oncogênicas c-fos/metabolismo , Receptores da Neurocinina-1/metabolismo , Substância P/metabolismo
3.
Neurosci Lett ; 737: 135301, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32784007

RESUMO

OBJECTIVE: To study the compatibility of traditional tracers and viral tracers with tissue clearing technology and to provide guidance in choosing suitable tracing methods for a specific tissue clearing technique. METHOD: Experiment 1: In this study, two different types of representative tracers, namely fluorescent dye tracers (Fluoro-Gold and Fluoro-Ruby) and viral tracers carrying fluorescent proteins (rAAV9-hSyn-mCherry-WPRE-pA and rAAV9-hSyn-EGFP-WPRE-pA), were selected to trace the cerebrospinal tract of the animals by microinjection. Furthermore, we presented the signal changes after using the three representative transparentizing methods, which included FRUIT (aqueous tissue clearing), 3DISCO (solvent-based tissue clearing), and uDISCO (solvent-based tissue clearing), were compared after slicing. Experiment 2: Based on the research mentioned above, Fluoro-Ruby was microinjected unilaterally into the primary motor cortex of rats, directly tracing the pyramidal tract to the spinal cord. Then, the entire brain and spinal cord were collected for tissue transparency using the 3DISCO method, after which three-dimensional imaging was performed using optical microscopic imaging equipment. RESULTS: Experiment 1 indicated that Fluoro-Gold and Fluoro-Ruby displayed better compatibility with the three transparent methods. The viral tracer exhibited higher compatibility with the FRUIT method, while its compatibility with 3DISCO and uDISCO was low. Furthermore, GFP was quenched more quickly and seriously than cherry protein under the same experimental conditions. Experiment 2: The Fluoro-Ruby tag displayed the presence of long-distance axons. For microscopic imaging, light sheet microscopy and two-photon microscopy were both used to identify the signals of tracers in transparent tissue. RESULTS: Both Fluoro-Gold and Fluoro-Ruby displayed excellent compatibility with tissue clearing technology, which, with dehydration and delipidation at its core, lead to quenching of fluorescence proteins, while exhibiting poor compatibility with viral tracers. In combination with tissue clearing technology and optical microscopy, the anterograde tracer Fluoro-Ruby could stereoscopically display the complete neural conduction pathway.


Assuntos
Corantes Fluorescentes , Marcadores do Trato Nervoso , Animais , Estudos de Viabilidade , Feminino , Ratos , Ratos Sprague-Dawley , Manejo de Espécimes
4.
Nat Commun ; 11(1): 1133, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111833

RESUMO

Understanding the principles of neuronal connectivity requires tools for efficient quantification and visualization of large datasets. The primate cortex is particularly challenging due to its complex mosaic of areas, which in many cases lack clear boundaries. Here, we introduce a resource that allows exploration of results of 143 retrograde tracer injections in the marmoset neocortex. Data obtained in different animals are registered to a common stereotaxic space using an algorithm guided by expert delineation of histological borders, allowing accurate assignment of connections to areas despite interindividual variability. The resource incorporates tools for analyses relative to cytoarchitectural areas, including statistical properties such as the fraction of labeled neurons and the percentage of supragranular neurons. It also provides purely spatial (parcellation-free) data, based on the stereotaxic coordinates of 2 million labeled neurons. This resource helps bridge the gap between high-density cellular connectivity studies in rodents and imaging-based analyses of human brains.


Assuntos
Atlas como Assunto , Encéfalo/anatomia & histologia , Callithrix/anatomia & histologia , Animais , Encéfalo/metabolismo , Encéfalo/fisiologia , Mapeamento Encefálico , Callithrix/fisiologia , Imageamento Tridimensional , Neocórtex/citologia , Neocórtex/metabolismo , Neocórtex/fisiologia , Vias Neurais , Marcadores do Trato Nervoso/administração & dosagem , Marcadores do Trato Nervoso/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Neurônios/fisiologia
5.
Mol Brain ; 13(1): 5, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931837

RESUMO

Neurotropic viral transsynaptic tracing is an increasingly powerful technique for dissecting the structure and function of neural circuits. Herpes simplex virus type 1 strain H129 has been widely used as an anterograde tracer. However, HSV tracers still have several shortcomings, including high toxicity, low sensitivity and non-specific retrograde labeling. Here, we aimed to construct high-brightness HSV anterograde tracers by increasing the expression of exogenous genes carried by H129 viruses. Using a Trojan horse-like strategy, a HSV/AAV (adeno-associated virus) chimaera termed H8 was generated to enhance the expression of a fluorescent marker. In vitro and in vivo assays showed that the exogenous gene was efficiently replicated and amplified by the synergism of the HSV vector and introduced AAV replication system. H8 reporting fluorescence was brighter than that of currently available H129 tracers, and H8 could be used for fast and effective anterograde tracing without additional immunostaining. These results indicated that foreign gene expression in HSV tracers could be enhanced by integrating HSV with AAV replication system. This approach may be useful as a general enhanced expression strategy for HSV-based tracing tools or gene delivery vectors.


Assuntos
Transporte Axonal/fisiologia , Encéfalo/citologia , Vírus Defeituosos/fisiologia , Dependovirus/fisiologia , Proteínas de Fluorescência Verde/análise , Vírus Auxiliares/fisiologia , Herpesvirus Humano 1/fisiologia , Vias Neurais/ultraestrutura , Técnicas de Rastreamento Neuroanatômico/métodos , Marcadores do Trato Nervoso/análise , Neurônios/ultraestrutura , Vírus Reordenados/fisiologia , Animais , Linhagem Celular , Núcleo Celular/virologia , Vírus Defeituosos/genética , Dependovirus/genética , Genes Reporter , Genes Sintéticos , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Vírus Auxiliares/genética , Herpesvirus Humano 1/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/virologia , Vírus Reordenados/genética , Proteínas do Complexo da Replicase Viral/genética , Replicação Viral
6.
Proc Natl Acad Sci U S A ; 116(46): 23326-23331, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31659044

RESUMO

Retinotopic specializations in the ventral visual stream, especially foveal adaptations, provide primates with high-acuity vision in the central visual field. However, visual field specializations have not been studied in the dorsal visual stream, dedicated to processing visual motion and visually guided behaviors. To investigate this, we injected retrograde neuronal tracers occupying the whole visuotopic representation of the middle temporal (MT) visual area in marmoset monkeys and studied the distribution and morphology of the afferent primary visual cortex (V1) projections. Contrary to previous reports, we found a heterogeneous population of V1-MT projecting neurons distributed in layers 3C and 6. In layer 3C, spiny stellate neurons were distributed mainly in foveal representations, while pyramidal morphologies were characteristic of peripheral eccentricities. This primate adaptation of the V1 to MT pathway is arranged in a way that we had not previously understood, with abundant stellate projection neurons in the high-resolution foveal portions, suggesting rapid relay of motion information to visual area MT. We also describe that the medial portion of the inferior pulvinar (PIm), which is the main thalamic input to area MT, shows a retinotopic organization, likely reflecting the importance of this pathway during development and the establishment of area MT topography.


Assuntos
Córtex Visual/anatomia & histologia , Animais , Mapeamento Encefálico , Callithrix , Marcadores do Trato Nervoso , Pulvinar/anatomia & histologia , Pulvinar/fisiologia , Córtex Visual/fisiologia
7.
Nat Commun ; 10(1): 4627, 2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31604917

RESUMO

Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are a popular chemogenetic technology for manipulation of neuronal activity in uninstrumented awake animals with potential for human applications as well. The prototypical DREADD agonist clozapine N-oxide (CNO) lacks brain entry and converts to clozapine, making it difficult to apply in basic and translational applications. Here we report the development of two novel DREADD agonists, JHU37152 and JHU37160, and the first dedicated 18F positron emission tomography (PET) DREADD radiotracer, [18F]JHU37107. We show that JHU37152 and JHU37160 exhibit high in vivo DREADD potency. [18F]JHU37107 combined with PET allows for DREADD detection in locally-targeted neurons, and at their long-range projections, enabling noninvasive and longitudinal neuronal projection mapping.


Assuntos
Drogas Desenhadas , Radioisótopos de Flúor/análise , Marcadores do Trato Nervoso/análise , Animais , Encéfalo , Clozapina/análogos & derivados , Clozapina/química , Células HEK293 , Haplorrinos , Humanos , Ligantes , Técnicas de Rastreamento Neuroanatômico/métodos , Marcadores do Trato Nervoso/química , Tomografia por Emissão de Pósitrons/métodos , Roedores
8.
Neurosci Lett ; 712: 134481, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494222

RESUMO

Echolocating bats emit various types of vocalizations for navigation and communication, and need to pay attention to vocal sounds. Projections from forebrain centers to auditory centers are involved in the attention to vocalizations, with the inferior colliculus (IC) being the main target of the projections. Here, using a retrograde tracer, we demonstrate that three forebrain structures, namely, the medial prefrontal cortex (mPFC), amygdala, and auditory cortex (AC), send direct descending projections to the central nucleus of IC. We found that all three structures projected to the bilateral IC. A comparison of the patterns of retrogradely labeled cells across animals suggests that the ipsilateral AC-IC projection is topographically organized, whereas mPFC-IC or amygdala-IC projections did not show clear topographic organization. Together with evidence from previous studies, these results suggest that three descending projections to the IC form loops between the forebrain and IC to make attention to various vocal sounds.


Assuntos
Tonsila do Cerebelo/fisiologia , Córtex Auditivo/fisiologia , Vias Auditivas/fisiologia , Ecolocação/fisiologia , Mesencéfalo/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Mapeamento Encefálico , Quirópteros , Técnicas de Rastreamento Neuroanatômico , Marcadores do Trato Nervoso
9.
J Chem Neuroanat ; 102: 101661, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31408693

RESUMO

Monosynaptic tracing using deletion-mutant rabies virus allows whole-brain mapping of neurons that are directly presynaptic to a targeted population of neurons. The most common and robust way of implementing it is to use Cre mouse lines in combination with Cre-dependent adeno-associated viral vectors for expression of the required genes in the targeted neurons before subsequent injection of the rabies virus. Here we present a step-by-step protocol for performing such experiments using first-generation (ΔG) rabies viral vectors.


Assuntos
Encéfalo/metabolismo , Técnicas de Rastreamento Neuroanatômico/métodos , Marcadores do Trato Nervoso , Neurônios/metabolismo , Vírus da Raiva
10.
Eur J Neurosci ; 50(9): 3445-3453, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31286598

RESUMO

The auditory system comprises some very large axonal terminals like the endbulb and calyx of Held and "giant" corticothalamic synapses. Previously, we described a hitherto unknown population of giant thalamocortical boutons arising from the medial division of the medial geniculate body (MGm) in the Mongolian gerbil, which terminate over a wide cortical range but in a columnar manner particularly in the extragranular layers of the auditory cortex. As a first step towards an understanding of their potential functional role, we here describe their ultrastructure combining anterograde tract-tracing with biocytin and electron microscopy. Quantitative ultrastructural analyses revealed that biocytin-labelled MGm boutons reach much larger sizes than other, non-labelled boutons. Also, mitochondria occupy more space within labelled boutons whereas synapses are of similar size. Labelled boutons are very heterogeneous in size but homogeneous with respect to their ultrastructural characteristics, with asymmetric synapses containing clear, round vesicles and targeting dendritic spines. Functionally, the ultrastructure of the MGm terminals indicates that they form excitatory contacts, which may transmit their information in a rapid, powerful and high-fidelity manner onto strategically advantageous compartments of their cortical target cells.


Assuntos
Córtex Auditivo/ultraestrutura , Corpos Geniculados/ultraestrutura , Técnicas de Rastreamento Neuroanatômico/métodos , Terminações Pré-Sinápticas/ultraestrutura , Tálamo/ultraestrutura , Animais , Gerbillinae , Lisina/análogos & derivados , Lisina/metabolismo , Masculino , Microscopia Eletrônica , Vias Neurais/metabolismo , Marcadores do Trato Nervoso/metabolismo
11.
J Anat ; 235(5): 953-961, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31347697

RESUMO

The glossopharyngeal nerve, via the carotid sinus nerve (CSN), presents baroreceptors from the internal carotid artery (ICA) and chemoreceptors from the carotid body. Although neurons in the nodose ganglion were labelled after injecting tracer into the carotid body, the vagal pathway to these baro- and chemoreceptors has not been identified. Neither has the glossopharyngeal intracranial afferent/sensory pathway that connects to the brainstem been defined. We investigated both of these issues in male Sprague-Dawley rats (n = 40) by injecting neural tracer wheat germ agglutinin-horseradish peroxidase into: (i) the peripheral glossopharyngeal or vagal nerve trunk with or without the intracranial glossopharyngeal rootlet being rhizotomized; or (ii) the nucleus of the solitary tract right after dorsal and ventral intracranial glossopharyngeal rootlets were dissected. By examining whole-mount tissues and brainstem sections, we verified that only the most rostral rootlet connects to the glossopharyngeal nerve and usually four caudal rootlets connect to the vagus nerve. Furthermore, vagal branches may: (i) join the CSN originating from the pharyngeal nerve base, caudal nodose ganglion, and rostral or caudal superior laryngeal nerve; or (ii) connect directly to nerve endings in the middle segment of the ICA or to chemoreceptors in the carotid body. The aortic depressor nerve always presents and bifurcates from either the rostral or the caudal part of the superior laryngeal nerve. The vagus nerve seemingly provides redundant carotid baro- and chemoreceptors to work with the glossopharyngeal nerve. These innervations confer more extensive roles on the vagus nerve in regulating body energy that is supplied by the cardiovascular, pulmonary and digestive systems.


Assuntos
Artéria Carótida Interna/metabolismo , Corpo Carotídeo/metabolismo , Células Quimiorreceptoras/metabolismo , Pressorreceptores/metabolismo , Nervo Vago/metabolismo , Animais , Masculino , Marcadores do Trato Nervoso , Ratos , Ratos Sprague-Dawley
12.
Neuroscience ; 409: 261-275, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-30930128

RESUMO

Injection of the anterograde tracer Phaseolus vulgaris leucoagglutinin (PHAL) into the rat rostral and caudal supramammillary nucleus (SUM) provided expected patterns of projections into the hippocampus and the septal region. In addition, unexpectedly intense projections were observed into the claustrum defined by parvalbumin expression. Injections of the retrograde tracer fluorogold (FG) into the hippocampus and the region of the claustrum showed that the cells of origin of these projections distributed similarly within the borders of the SUM. The SUM is usually involved in control of hippocampal theta activity, but the observation of intense projections into the claustrum indicates that it may also influence isocortical processes. Therefore, the SUM may coordinate sensory processing in the isocortex with memory formation in the hippocampus.


Assuntos
Claustrum/fisiologia , Hipotálamo Posterior/fisiologia , Neurônios/fisiologia , Animais , Claustrum/efeitos dos fármacos , Hipotálamo Posterior/efeitos dos fármacos , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiologia , Técnicas de Rastreamento Neuroanatômico , Marcadores do Trato Nervoso/farmacologia , Neurônios/efeitos dos fármacos , Ratos
13.
J Neurophysiol ; 121(5): 1718-1734, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30786219

RESUMO

Two macroscopic parameters describe the interstitial diffusion of substances in the extracellular space (ECS) of the brain, the ECS volume fraction α and the diffusion tortuosity λ. Past methods based on sampling the extracellular concentration of a membrane-impermeable ion tracer, such as tetramethylammonium (TMA+), can characterize either the dynamic α(t) alone or the constant α and λ in resting state but never the dynamic α(t) and λ(t) simultaneously in short-lived brain events. In this work, we propose to use a sinusoidal method of TMA+ to provide time-resolved quantification of α(t) and λ(t) in acute brain events. This method iontophoretically injects TMA+ in the brain ECS by a sinusoidal time pattern, samples the resulting TMA+ diffusion waveform at a distance, and analyzes the transient modulations of the amplitude and phase lag of the sampled TMA+ waveform to infer α(t) and λ(t). Applicability of the sinusoidal method was verified through computer simulations of the sinusoidal TMA+ diffusion waveform in cortical spreading depression. Parameter sensitivity analysis identified the sinusoidal frequency and the interelectrode distance as two key operating parameters. Compared with other TMA+-based methods, the sinusoidal method can more accurately capture the dynamic α(t) and λ(t) in acute brain events and is equally applicable to other pathological episodes such as epilepsy, transient ischemic attack, and brain injury. Future improvement of the method should focus on high-fidelity extraction of the waveform amplitude and phase angle. NEW & NOTEWORTHY An iontophoretic sinusoidal method of tetramethylammonium is described to capture the dynamic brain extracellular space volume fraction α and diffusion tortuosity λ. The sinusoidal frequency and interelectrode distance are two key operating parameters affecting the method's accuracy in capturing α(t) and λ(t). High-fidelity extraction of the waveform amplitude and phase lag is critical to successful sinusoidal analyses.


Assuntos
Encéfalo/citologia , Potenciais Evocados , Espaço Extracelular/fisiologia , Modelos Neurológicos , Técnicas de Rastreamento Neuroanatômico/métodos , Algoritmos , Animais , Encéfalo/fisiologia , Difusão , Espaço Extracelular/metabolismo , Marcadores do Trato Nervoso/farmacocinética , Compostos de Amônio Quaternário/farmacocinética , Ratos , Tempo de Reação
14.
J Neurophysiol ; 121(5): 1735-1747, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30786223

RESUMO

Extracellular diffusion in the brain is customarily characterized by two parameters, the extracellular space (ECS) volume fraction α and the diffusion tortuosity λ. How these two parameters are temporarily modified and correlated in a physiological/pathological event remains unclear to date. Using tetramethylammonium (TMA+) as an ECS ion tracer in a newly updated iontophoretic sinusoidal method, we studied in this work the dynamic α(t) and λ(t) in rat somatosensory cortex during spreading depression (SD). Temporal variations of α(t) and λ(t), as evoked by SD, were obtained through analyses of the extracellular TMA+ diffusion waveform resulting from a sinusoidally modulated point source. Most of the time, cortical SD induced coordinated α(t) decreases and λ(t) increases. In rare occasions, SD induced sole decreases of α(t) with no changes in λ(t). The independent modulation of α(t) and λ(t) was neither associated with cortical anatomy nor with the specific shape of the SD field potential wave. Changes of α(t) and λ(t) often took place acutely at the onset of SD, followed by a more transient modulation. Compared with the prior iontophoretic methods of TMA+, the sinusoidal method provides time-resolved quantification of α(t) and λ(t) in relative terms but also raises a higher property requirement on the TMA+-selective microelectrode. The sinusoidal method could become a valuable tool in the studies of the dynamic ECS response in various brain events. NEW & NOTEWORTHY An iontophoretic sinusoidal method was applied to study the dynamic changes of two extracellular space parameters, the extracellular volume fraction α(t) and tortuosity λ(t), in the brain during cortical spreading depression. Both parameters showed coordinated (most often) and independent (rarely) modulations in spreading depression. The sinusoidal method is equally applicable to other acute pathological events and a valuable tool to study the functional role of extracellular space in brain events.


Assuntos
Córtex Cerebral/fisiologia , Depressão Alastrante da Atividade Elétrica Cortical , Espaço Extracelular/fisiologia , Algoritmos , Animais , Córtex Cerebral/citologia , Feminino , Masculino , Técnicas de Rastreamento Neuroanatômico/métodos , Marcadores do Trato Nervoso/farmacocinética , Neurônios/fisiologia , Compostos de Amônio Quaternário/farmacocinética , Ratos , Ratos Sprague-Dawley , Tempo de Reação
15.
J Comp Neurol ; 527(5): 942-956, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30311651

RESUMO

One of the main subcortical inputs to the basolateral nucleus of the amygdala (BL) originates from a group of dorsal thalamic nuclei located at or near the midline, mainly from the central medial (CMT), and paraventricular (PVT) nuclei. Although similarities among the responsiveness of BL, CMT, and PVT neurons to emotionally arousing stimuli suggest that these thalamic inputs exert a significant influence over BL activity, little is known about the synaptic relationships that mediate these effects. Thus, the present study used Phaseolus vulgaris-leucoagglutinin (PHAL) anterograde tracing and electron microscopy to shed light on the ultrastructural properties and synaptic targets of CMT and PVT axon terminals in the rat BL. Virtually all PHAL-positive CMT and PVT axon terminals formed asymmetric synapses. Although CMT and PVT axon terminals generally contacted dendritic spines, a substantial number ended on dendritic shafts. To determine whether these dendritic shafts belonged to principal or local-circuit cells, calcium/calmodulin-dependent protein kinase II (CAMKIIα) immunoreactivity was used as a selective marker of principal BL neurons. In most cases, dendritic shafts postsynaptic to PHAL-labeled CMT and PVT terminals were immunopositive for CaMKIIα. Overall, these results suggest that CMT and PVT inputs mostly target principal BL neurons such that when CMT or PVT neurons fire, little feed-forward inhibition counters their excitatory influence over principal cells. These results are consistent with the possibility that CMT and PVT inputs constitute major determinants of BL activity.


Assuntos
Tonsila do Cerebelo/ultraestrutura , Núcleos da Linha Média do Tálamo/ultraestrutura , Sinapses/ultraestrutura , Tonsila do Cerebelo/metabolismo , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Dendritos/metabolismo , Dendritos/ultraestrutura , Masculino , Núcleos da Linha Média do Tálamo/metabolismo , Marcadores do Trato Nervoso , Fito-Hemaglutininas , Ratos Sprague-Dawley , Sinapses/metabolismo
16.
J Affect Disord ; 242: 188-194, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30193189

RESUMO

BACKGROUND: Neurotransmitter substance P (SP) and its preferred neurokinin-1 receptor (NK1R) have been implicated in the treatment of affective and addiction disorders. Despite promising preclinical data on antidepressant action, the clinical trials of NK1R antagonists in major depression have been disappointing. There are no direct in vivo imaging studies on NK1R characteristics in patients with a major depressive disorder (MDD). METHODS: In this cross-sectional case-control study, we recruited nine never-medicated patients with moderate to severe MDD and nine matched healthy controls. NK1R availability (NK1R binding potential, BPND) was measured with in vivo 3-D positron emission tomography and a specific NK1 receptor tracer [18F]SPA-RQ. Clinical symptoms were assessed with the 17-item Hamilton Rating Scale for Depression (HAM-D17). RESULTS: NK1R-BPND did not differ statistically significantly between patients with MDD and healthy controls. HAM-D17 total scores (range 21-32) correlated positively with NK1R-BPND in cortical and limbic areas. HAM-D17 subscale score for anxiety symptoms correlated positively with NK1R-BPND in specific brain areas implicated in fear and anxiety. LIMITATIONS: Small sample size. Low variability in the clinical HAM-D subscale ratings may affect the observed correlations. CONCLUSIONS: Our preliminary results do not support a different baseline expression of NK1Rs in a representative sample of never-medicated patients with MDD during a current moderate/severe depressive episode. The modulatory effect of NK1Rs on affective symptoms is in line with early positive results on antidepressant action of NK1 antagonists. However, the effect is likely to be too weak for treatment of MDD with NK1R antagonists alone in clinical practice.


Assuntos
Química Encefálica/fisiologia , Transtorno Depressivo Maior/metabolismo , Receptores da Neurocinina-1/metabolismo , Adulto , Antidepressivos/uso terapêutico , Ansiedade/diagnóstico por imagem , Ansiedade/metabolismo , Estudos de Casos e Controles , Estudos Transversais , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/tratamento farmacológico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antagonistas dos Receptores de Neurocinina-1/uso terapêutico , Marcadores do Trato Nervoso , Projetos Piloto , Piperidinas , Tomografia por Emissão de Pósitrons/métodos , Tetrazóis
17.
Elife ; 72018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30454553

RESUMO

The stochastic multicolor labeling method 'Brainbow' is a powerful strategy to label multiple neurons differentially with fluorescent proteins; however, the fluorescence levels provided by the original attempts to use this strategy were inadequate. In the present study, we developed a stochastic multicolor labeling method with enhanced expression levels that uses a tetracycline-operator system (Tetbow). We optimized Tetbow for either plasmid or virus vector-mediated multicolor labeling. When combined with tissue clearing, Tetbow was powerful enough to visualize the three-dimensional architecture of individual neurons. Using Tetbow, we were able to visualize the axonal projection patterns of individual mitral/tufted cells along several millimeters in the mouse olfactory system. We also developed a Tetbow system with chemical tags, in which genetically encoded chemical tags were labeled with synthetic fluorophores. This was useful in expanding the repertoire of the fluorescence labels and the applications of the Tetbow system. Together, these new tools facilitate light-microscopy-based neuronal tracing at both a large scale and a high resolution.


Assuntos
Técnicas de Rastreamento Neuroanatômico/métodos , Marcadores do Trato Nervoso/metabolismo , Coloração e Rotulagem/métodos , Animais , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Bulbo Olfatório/anatomia & histologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
18.
PLoS One ; 13(10): e0205133, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30289890

RESUMO

Cholera toxin subunit B (CTB) and Fluorogold(FG) are two widely utilized retrograde tracers to assess the number and function of retinal ganglion cells (RGCs). However, the relative advantages and disadvantages of these tracers remain unclear, which may lead to their inappropriate application. In this study, we compared these tracers by separately injecting the tracer into the superior Colliculi (SC) in rats, one or 2 weeks later, the rats were sacrificed, and their retinas, brains, and optic nerves were collected. From the first to second week, FG displayed a greater number of labeled RGCs and a larger diffusion area in the SC than CTB; The number of CTB labeled RGCs and the diffusion area of CTB in the SC increased significantly, but there was no distinction between FG; Furthermore, CTB exhibited more labeled RGC neurites and longer neurites than FG, but no difference was evident between the same trace; The optic nerves labeled using CTB were much clearer than those labeled using FG. In conclusion, both CTB and FG can be used for the retrograde labeling of RGCs in rats at 1 or 2 weeks. FG achieves retrograde labeling of a greater number of RGCs than CTB, whereas CTB better delineates the morphology of RGCs. Furthermore, CTB seems more suitable for retrograde labeling of some small, non-image forming nuclei in the brain to which certain RGC subtypes project their axons.


Assuntos
Toxina da Cólera , Corantes Fluorescentes , Técnicas de Rastreamento Neuroanatômico , Marcadores do Trato Nervoso , Células Ganglionares da Retina/citologia , Estilbamidinas , Animais , Feminino , Microscopia de Fluorescência , Neuritos , Nervo Óptico/citologia , Ratos Sprague-Dawley , Colículos Superiores/citologia , Vias Visuais/citologia
19.
Neuroscience ; 388: 317-329, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30077619

RESUMO

We have recently revealed that the proprioceptive signal from jaw-closing muscle spindles (JCMSs) is conveyed to the dorsal part of granular insular cortex rostroventrally adjacent to the rostralmost part of secondary somatosensory cortex (dGIrvs2) via the caudo-ventromedial edge (VPMcvm) of ventral posteromedial thalamic nucleus (VPM) in rats. However, it remains unclear to which cortical or subcortical structures the JCMS proprioceptive information is subsequently conveyed from the dGIrvs2. To test this issue, we injected an anterograde tracer, biotinylated dextranamine, into the electophysiologically identified dGIrvs2, and analyzed the resultant distribution profiles of labeled axon terminals in rats. Labeled terminals were distributed with an ipsilateral predominance. In the cerebral cortex, they were seen in the primary and secondary somatosensory cortices, lateral and medial agranular cortices and dorsolateral orbital cortex. In the basal ganglia, they were found in the caudate putamen, core part of accumbens nucleus, lateral globus pallidus, subthalamic nucleus, and substantia nigra pars compacta and pars reticulata. They were also observed in the central amygdaloid nucleus and extended amygdala (the interstitial nucleus of posterior limb of anterior commissure and the juxtacapsular part of lateral division of bed nucleus of stria terminalis). In the thalamus, they were seen in the reticular nucleus, ventromedial nucleus, core VPM, parvicellular part of ventral posterior nucleus, oval paracentral nucleus, medial and triangular parts of posterior nucleus, and zona incerta as well as the VPMcvm. These data suggest that the JCMS proprioceptive information through the dGIrvs2 is transmitted to the emotional 'limbic' regions as well as sensorimotor regions.


Assuntos
Córtex Cerebral/anatomia & histologia , Córtex Cerebral/fisiologia , Propriocepção/fisiologia , Tonsila do Cerebelo/anatomia & histologia , Tonsila do Cerebelo/fisiologia , Animais , Gânglios da Base/anatomia & histologia , Gânglios da Base/fisiologia , Biotina/análogos & derivados , Dextranos , Potenciais Evocados , Face/inervação , Lateralidade Funcional , Masculino , Boca/inervação , Vias Neurais/anatomia & histologia , Vias Neurais/fisiologia , Técnicas de Rastreamento Neuroanatômico , Marcadores do Trato Nervoso , Neurônios/citologia , Neurônios/fisiologia , Ratos Wistar , Tálamo/anatomia & histologia , Tálamo/fisiologia
20.
J Neurosci Methods ; 308: 228-239, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30098326

RESUMO

BACKGROUND: Viral transneuronal tracing has become a well established technology used to define the synaptic architecture of polysynaptic neural networks. NEW METHOD: In this report we define the neuroinvasive profile and reporter expression of a new recombinant of the Bartha strain of pseudorabies virus (PRV). The new recombinant, PRV-290, expresses the mTurquoise2 fluorophor and is designed to complement other isogenic recombinants of Bartha that express different reporters of infection. Results & Comparison with Existing Methods: PRV-290 was injected either alone or in combination with isogenic recombinants of PRV that express enhanced green fluorescent protein (EGFP; PRV-152) or monomeric red fluorescent protein (mRFP; PRV-614). Circuits previously defined using PRV-152 and PRV-614 were used for the analysis. The data demonstrate that PRV-290 is a retrograde transneuronal tracer with temporal kinetics similar to those of its isogenic recombinants. Stable expression of the diffusible mTurquoise2 reporter filled infected neurons, with the extent and intensity of labeling increasing with advancing post inoculation survival. In multiple injection experiments, PRV-290 established productive infections in neurons also replicating PRV-152 and/or PRV-614. This novel demonstration of three recombinants infecting individual neurons represents an important advance in the technology. CONCLUSION: Collectively, these data demonstrate that PRV-290 is a valuable addition to the viral tracer toolbox for transneuronal tracing of neural circuitry.


Assuntos
Encéfalo/citologia , Encéfalo/virologia , Herpesvirus Suídeo 1/fisiologia , Técnicas de Rastreamento Neuroanatômico/métodos , Neurônios/virologia , Animais , Linhagem Celular , Vetores Genéticos , Masculino , Vias Neurais/citologia , Vias Neurais/virologia , Marcadores do Trato Nervoso , Neurônios/citologia , Ratos Sprague-Dawley , Vísceras/citologia , Vísceras/virologia
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