Ultrastructural localization of tyrosine hydroxylase in tree shrew nucleus accumbens core and shell

McCollum, Lesley A.; Roberts, Rosalinda C.

doi:10.1016/j.neuroscience.2014.04.024

Cited by 19 publications

(21 citation statements)

References 79 publications

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“…10 Regions from the core and shell were blocked using the calbindin-stained sections as a guide. For each region, 3 blocks per case, at least 240 μm apart rostrocaudally, were used to obtain semithin sections.…”

Section: Electron Microscopymentioning

confidence: 99%

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Elevated Excitatory Input to the Nucleus Accumbens in Schizophrenia: A Postmortem Ultrastructural Study

McCollum

Walker

Roche

et al. 2015

SCHBUL

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The cause of schizophrenia (SZ) is unknown and no single region of the brain can be pinpointed as an area of primary pathology. Rather, SZ results from dysfunction of multiple neurotransmitter systems and miswiring between brain regions. It is necessary to elucidate how communication between regions is disrupted to advance our understanding of SZ pathology. The nucleus accumbens (NAcc) is a prime region of interest, where inputs from numerous brain areas altered in SZ are integrated. Aberrant signaling in the NAcc is hypothesized to cause symptoms of SZ, but it is unknown if these abnormalities are actually present. Electron microscopy was used to study the morphology of synaptic connections in SZ. The NAcc core and shell of 6 SZ subjects and 8 matched controls were compared in this pilot study. SZ subjects had a 19% increase in the density of asymmetric axospinous synapses (characteristic of excitatory inputs) in the core, but not the shell. Both groups had similar densities of symmetric synapses (characteristic of inhibitory inputs). The postsynaptic densities of asymmetric synapses had 22% smaller areas in the core, but not the shell. These results indicate that the core receives increased excitatory input in SZ, potentially leading to dysfunctional dopamine neurotransmission and cortico-striatal-thalamic stimulus processing. The reduced postsynaptic density size of asymmetric synapses suggests impaired signaling at these synapses. These findings enhance our understanding of the role the NAcc might play in SZ and the interaction of glutamatergic and dopaminergic abnormalities in SZ.Key words: electron microscopy/anatomy/striatum/ synapseThe exact pathophysiology for the origin of schizophrenia (SZ) is unknown, however evidence from decades of research implies that interactions between multiple brain regions and multiple neurotransmitter systems are likely at play. One region that is implicated in SZ pathology is the nucleus accumbens (NAcc). The NAcc integrates signaling from multiple regions of the brain, receiving input from areas including the prefrontal cortex, hippocampus, amygdala, thalamus, and midbrain.1 Importantly, all of these areas have been associated with SZ, making the NAcc a prime region for integrating multiple disrupted areas to provide a comprehensive understanding of SZ pathology.2 Reciprocal connections between the NAcc and substantia nigra/ventral tegmental area (SN/VTA) indicate further importance of this region. Via these connections, the NAcc modulates dopaminergic input to the dorsal striatum, 3 and striatal dopamine (DA) dysfunction is a hallmark characteristic of the disorder.4 Though many studies have implicated the NAcc in SZ, none have been able to describe its circuitry.The purpose of this study was to provide the first ultrastructural analysis in postmortem human NAcc, and examine the neurocircuitry in the NAcc in SZ to establish the role this region may play in the disorder. We used stereological analysis of electron micrographs in postmortem SZ to analyze the organization an...

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Section: Electron Microscopymentioning

confidence: 99%

“…Serial ultrathin sections (90 nm thickness) from each block were mounted on Formvar-coated copper grids, and photographed at 80 kV on a Hitachi transmission electron microscope, as detailed previously. 10 …”

Section: Nucleus Accumbens Ultrastructure In Schizophreniamentioning

confidence: 99%

Elevated Excitatory Input to the Nucleus Accumbens in Schizophrenia: A Postmortem Ultrastructural Study

McCollum

Walker

Roche

et al. 2015

SCHBUL

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“…In addition to these common solutions, the shell was further subdivided into medial and lateral areas, or even more subregions, based on their unique sets of inputs and outputs [Ikemoto, 2007]. The rostral pole was identified because of its specific efferent projections in rodents [Zahm and Brog, 1992;Zahm and Heimer, 1993] but not in primates [Ikemoto et al, 1995;McCollum and Roberts, 2014]. Although multiple levels of complex organization have been identified, to date the shell-core dichotomy has been the most intensely investigated.…”

Section: Introductionmentioning

confidence: 99%

Multimodal connectivity‐based parcellation reveals a shell‐core dichotomy of the human nucleus accumbens

Xia

Fan

Chen

et al. 2017

Human Brain Mapping

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The subdifferentiation of the nucleus accumbens (NAc) has been extensively studied using neuroanatomy and histochemistry, yielding a well-accepted dichotomic shell/core architecture that reflects dissociable roles, such as in reward and aversion, respectively. However, in vivo parcellation of these structures in humans has been rare, potentially impairing future research into the structural and functional characteristics and alterations of putative NAc subregions. Here, we used three complementary parcellation schemes based on tractography, task-independent functional connectivity, and task-dependent co-activation to investigate the regional differentiation within the NAc. We found that a 2-cluster solution with shell-like and core-like subdivisions provided the best description of the data and was consistent with the earlier anatomical shell/core architecture. The consensus clusters from this optimal solution, which was based on the three schemes, were used as the final parcels for the subsequent connection analyses. The resulting connectivity patterns presented inter-hemispheric symmetry, convergence and divergence across the modalities, and, most importantly, clearly distinct patterns between the two subregions. This convergent connectivity patterns also confirmed the connections in animal models, supporting views that the two subregions could have antagonistic roles in some circumstances. Finally, the identified parcels should be helpful in further neuroimaging studies of the NAc.

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“…Species‐dependent differentiation provides some insights into the evolution and adaptation of cerebellar lobules in various mammals (Luo et al, ).According to recent studies, the tree shrew is the closest living relative of primates (Fan et al, ; Kriegs, Churakov, Jurka, Brosius, & Schmitz, ; Yao, ). Other nongenomic evidences of morphological and anatomical characteristics in the tree shrew brain also support the relationship of tree shrews to primates (McCollum & Roberts, ; Ni et al, ; Ni et al, ; Rice, Roberts, Melendez‐Ferro, & Perez‐Costas, ; Romer et al, ). Previous studies have indicated that the tree shrews is widely used to study the visual system (Baldwin, Balaram, & Kaas, ; Petry & Bickford, ), motor system (Baldwin, Cooke, & Krubitzer, ), social stress (Fuchs & Flugge, ; Wang et al, ) and other neural systems.…”

Section: Introductionmentioning

confidence: 73%

The tree shrew cerebellum atlas: Systematic nomenclature, neurochemical characterization, and afferent projections

Huang

Luo

et al. 2018

J of Comparative Neurology

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The cerebellum is involved in the control of movement, emotional responses, and reward processing. The tree shrew is the closest living relative of primates. However, little is known not only about the systematic nomenclature for the tree shrew cerebellum but also about the detailed neurochemical characterization and afferent projections. In this study, Nissl staining and acetylcholinesterase histochemistry were used to reveal anatomical features of the cerebellum of tree shrews (Tupaia belangeri chinensis). The cerebellar cortex presented a laminar structure. The morphological characteristics of the cerebellum were comprehensively described in the coronal, sagittal, and horizontal sections. Moreover, distributive maps of calbindin-immunoreactive (-ir) cells in the Purkinje cell layer of the cerebellum of tree shrews were depicted using coronal, sagittal, and horizontal schematics. In addition, 5th cerebellar lobule (5Cb)-projecting neurons were present in the pontine nuclei, reticular nucleus, spinal vestibular nucleus, ventral spinocerebellar tract, and inferior olive of the tree shrew brain. The anterior part of the paramedian lobule of the cerebellum (PMa) received mainly strong innervation from the lateral reticular nucleus, inferior olive, pontine reticular nucleus, spinal trigeminal nucleus, pontine nuclei, and reticulotegmental nucleus of the pons. The present results provide the first systematic nomenclature, detailed atlas of the whole cerebellum, and whole-brain mapping of afferent projections to the 5Cb and PMa in tree shrews. Our findings provide morphological support for tree shrews as an alternative model for studies of human cerebellar pathologies.

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Ultrastructural localization of tyrosine hydroxylase in tree shrew nucleus accumbens core and shell

Cited by 19 publications

References 79 publications

Elevated Excitatory Input to the Nucleus Accumbens in Schizophrenia: A Postmortem Ultrastructural Study

Elevated Excitatory Input to the Nucleus Accumbens in Schizophrenia: A Postmortem Ultrastructural Study

Multimodal connectivity‐based parcellation reveals a shell‐core dichotomy of the human nucleus accumbens

The tree shrew cerebellum atlas: Systematic nomenclature, neurochemical characterization, and afferent projections

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