Synaptic organization of the gustatory NST

1994 ◽  
Vol 52 ◽  
pp. 150-151
Author(s):  
M. C. Whitehead
Keyword(s):  
Central Nervous System ◽  
Dendritic Spines ◽  
Fundamental Problem ◽  
Cell Types ◽  
Brain Regions ◽  
Excitatory Synapses ◽  
Solitary Tract ◽  
Synaptic Organization ◽  
Synaptic Junctions ◽  
Afferent Terminals

A fundamental problem in taste research is to determine how gustatory signals are processed and disseminated in the mammalian central nervous system. An important first step toward understanding information processing is the identification of cell types in the nucleus of the solitary tract (NST) and their synaptic relationships with oral primary afferent terminals. Facial and glossopharyngeal (LIX) terminals in the hamster were labelled with HRP, examined with EM, and characterized as containing moderate concentrations of medium-sized round vesicles, and engaging in asymmetrical synaptic junctions. Ultrastructurally the endings resemble excitatory synapses in other brain regions.Labelled facial afferent endings in the RC subdivision synapse almost exclusively with distal dendrites and dendritic spines of NST cells. Most synaptic relationships between the facial synapses and the dendrites are simple. However, 40% of facial endings engage in complex synaptic relationships within glomeruli containing unlabelled axon endings particularly ones termed "SP" endings. SP endings are densely packed with small, pleomorphic vesicles and synapse with both the facial endings and their postsynaptic dendrites by means of nearly symmetrical junctions.

The development of the central nervous system in Capitella capitata (Polychaeta, Annelida)

1982 ◽  
Vol 60 (10) ◽  
pp. 2284-2295 ◽  
Author(s):  
Rohan Bhup ◽  
Joan R. Marsden
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Light And Electron Microscopy ◽  
Muscular Activity ◽  
Cell Types ◽  
Synaptic Junctions ◽  
The Central Nervous System ◽  
Stage Development ◽  
Capitella Capitata ◽  
Electron Lucent

The development of the central nervous system of the polychaete Capitella capitata is described in a series of five stages, using both light and electron microscopy. The initial cerebral primordium is paired and differentiates into two cell types, one electron lucent and granular, the other electron dense. The onset of muscular activity precedes the initiation of axonal growth. Neural differentiation appears to progress anteroposteriorly. Earliest morphological indications of neuromuscular contact are found in the metatrochophore stage. Classically differentiated synaptic junctions were not seen, even in the final settling stage. Development in C. capitata is essentially direct; there are very few larval features and none of these concern the emerging nervous system.

Acquired Diseases of the Nervous System

2018 ◽  
pp. 219-243
Author(s):  
Leila Chimelli ◽  
Françoise Gray
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Metabolic Diseases ◽  
Cell Types ◽  
Brain Regions ◽  
Vitamin Deficiencies ◽  
System P ◽  
Wide Range ◽  
The Central Nervous System ◽  
Anatomic Region

This chapter describes and illustrates the different neuropathological changes observed in a wide range of systemic acquired metabolic diseases that affect the central or peripheral nervous systems: hypoxia, hypoglycemia, hyperthermia, disorders of serum electrolytes, vitamin deficiencies, and exogenous intoxications, particularly alcoholism and intoxications by drugs, methanol, and heavy metals. In the central nervous system, lesions may find expression via selective involvement of some brain regions, with simultaneous complete preservation of others. The pathogenesis of the predisposition to injury for a particular anatomic region or for some specific set of cell types (neurons mostly) varies considerably form one disease to another and is undoubtedly multifactorial. The chapter also considers central nervous system abnormalities secondary to systemic diseases, including respiratory encephalopathies, hepatic encephalopathy, multifocal necrotizing leukoencephalopathy, and paraneoplastic encephalomyelopathies.

Three-dimensional structure of dendritic spines, neuronal specializations that impart both stability and flexibility to synaptic function

1993 ◽  
Vol 51 ◽  
pp. 92-93
Author(s):  
Kristen M. Harris
Keyword(s):  
Dendritic Spines ◽  
Three Dimensional ◽  
Synaptic Function ◽  
Dimensional Structure ◽  
Excitatory Synapses ◽  
Concept Of Function ◽  
Section Electron ◽  
High Quality Information ◽  
The Central Nervous System ◽  
Mathematical Analyses

Dendritic spines are the tiny protrusions that stud the surface of many neurons and they are the location of over 90% of all excitatory synapses that occur in the central nervous system. Their small size and variable shapes has in large part made detailed study of their structure refractory to conventional light microscopy and single section electron microscopy (EM). Yet their widespread occurrence and likely involvement in learning and memory has motivated extensive efforts to obtain quantitative descriptions of spines in both steady state and dynamic conditions. Since the seminal mathematical analyses of D’Arcy Thompson, the power of establishing quantitatively key parameters of structure has become recognized as a foundation of successful biological inquiry. For dendritic spines highly precise determinations of structure and its variation are proving themselves as the kingpin for establishing a valid concept of function. The recent conjunction of high quality information about the structure, function, and theoretical implications of dendritic spines has produced a flurry of new considerations of their role in synaptic transmission.

scholarly journals Shisa6 mediates cell-type specific regulation of depression in the nucleus accumbens

2021 ◽  
Author(s):  
Hee-Dae Kim ◽  
Jing Wei ◽  
Tanessa Call ◽  
Nicole Teru Quintus ◽  
Alexander J. Summers ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Molecular Mechanisms ◽  
Cell Types ◽  
Current Treatment ◽  
Specific Cell ◽  
Excitatory Synapses ◽  
Cell Type ◽  
Cell Type Specific ◽  
Specific Regulation ◽  
Circuit Function

AbstractDepression is the leading cause of disability and produces enormous health and economic burdens. Current treatment approaches for depression are largely ineffective and leave more than 50% of patients symptomatic, mainly because of non-selective and broad action of antidepressants. Thus, there is an urgent need to design and develop novel therapeutics to treat depression. Given the heterogeneity and complexity of the brain, identification of molecular mechanisms within specific cell-types responsible for producing depression-like behaviors will advance development of therapies. In the reward circuitry, the nucleus accumbens (NAc) is a key brain region of depression pathophysiology, possibly based on differential activity of D1- or D2- medium spiny neurons (MSNs). Here we report a circuit- and cell-type specific molecular target for depression, Shisa6, recently defined as an AMPAR component, which is increased only in D1-MSNs in the NAc of susceptible mice. Using the Ribotag approach, we dissected the transcriptional profile of D1- and D2-MSNs by RNA sequencing following a mouse model of depression, chronic social defeat stress (CSDS). Bioinformatic analyses identified cell-type specific genes that may contribute to the pathogenesis of depression, including Shisa6. We found selective optogenetic activation of the ventral tegmental area (VTA) to NAc circuit increases Shisa6 expression in D1-MSNs. Shisa6 is specifically located in excitatory synapses of D1-MSNs and increases excitability of neurons, which promotes anxiety- and depression-like behaviors in mice. Cell-type and circuit-specific action of Shisa6, which directly modulates excitatory synapses that convey aversive information, identifies the protein as a potential rapid-antidepressant target for aberrant circuit function in depression.

scholarly journals Emerging Synaptic Molecules as Candidates in the Etiology of Neurological Disorders

2017 ◽  
Vol 2017 ◽  
pp. 1-25 ◽  
Author(s):  
Viviana I. Torres ◽  
Daniela Vallejo ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Central Nervous System ◽  
Neurological Disorders ◽  
Neuronal Development ◽  
Protein Complexes ◽  
Synaptic Proteins ◽  
Excitatory Synapses ◽  
Complex Structures ◽  
Disease Phenotype ◽  
The Central Nervous System ◽  
Invertebrate Models

Synapses are complex structures that allow communication between neurons in the central nervous system. Studies conducted in vertebrate and invertebrate models have contributed to the knowledge of the function of synaptic proteins. The functional synapse requires numerous protein complexes with specialized functions that are regulated in space and time to allow synaptic plasticity. However, their interplay during neuronal development, learning, and memory is poorly understood. Accumulating evidence links synapse proteins to neurodevelopmental, neuropsychiatric, and neurodegenerative diseases. In this review, we describe the way in which several proteins that participate in cell adhesion, scaffolding, exocytosis, and neurotransmitter reception from presynaptic and postsynaptic compartments, mainly from excitatory synapses, have been associated with several synaptopathies, and we relate their functions to the disease phenotype.

Low concentrations of hydrogen sulphide alter monoamine levels in the developing rat central nervous system

1992 ◽  
Vol 70 (11) ◽  
pp. 1515-1518 ◽  
Author(s):  
B. Skrajny ◽  
R. S. Hannah ◽  
S. H. Roth
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Frontal Cortex ◽  
Hydrogen Sulphide ◽  
Chronic Exposure ◽  
Brain Regions ◽  
Target Organs ◽  
Low Concentrations ◽  
The Central Nervous System ◽  
Developing Rat

The central nervous system is one of the primary target organs for hydrogen sulphide (H2S) toxicity; however, there are limited data on the neurotoxic effects of low-dose chronic exposure on the developing nervous system. Levels of serotonin and norepinephrine in the developing rat cerebellum and frontal cortex were determined following chronic exposure to 20 and 75 ppm H2S during perinatal development. Both monoamines were altered in rats exposed to 75 ppm H2S compared with controls; serotonin levels were significantly increased at days 14 and 21 postnatal in both brain regions, and norepinephrine levels were significantly increased at days 7, 14, and 21 postnatal in cerebellum and at day 21 in the frontal cortex. Exposure to 20 ppm H2S significantly increased the levels of serotonin in the frontal cortex at day 21, whereas levels of norepinephrine were significantly reduced in the frontal cortex at days 14 and 21, and at day 14 in the cerebellum.Key words: hydrogen sulphide, monoamines, serotonin, norepinephrine, neurotoxicity.

scholarly journals Single-cell transcriptomic analysis elucidates APOE genotype specific changes across cell types in two brain regions in Alzheimer’s disease

2021 ◽  
Author(s):  
Stella Belonwu ◽  
Yaqiao Li ◽  
Daniel Bunis ◽  
Arjun Arkal Rao ◽  
Caroline Warly Solsberg ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Single Cell ◽  
Molecular Mechanisms ◽  
Apoe Genotype ◽  
Cell Types ◽  
Brain Regions ◽  
Single Cell Level ◽  
Cell Level ◽  
Single Nucleus

Abstract Alzheimer’s Disease (AD) is a complex neurodegenerative disease that gravely affects patients and imposes an immense burden on caregivers. Apolipoprotein E4 (APOE4) has been identified as the most common genetic risk factor for AD, yet the molecular mechanisms connecting APOE4 to AD are not well understood. Past transcriptomic analyses in AD have revealed APOE genotype-specific transcriptomic differences; however, these differences have not been explored at a single-cell level. Here, we leverage the first two single-nucleus RNA sequencing AD datasets from human brain samples, including nearly 55,000 cells from the prefrontal and entorhinal cortices. We observed more global transcriptomic changes in APOE4 positive AD cells and identified differences across APOE genotypes primarily in glial cell types. Our findings highlight the differential transcriptomic perturbations of APOE isoforms at a single-cell level in AD pathogenesis and have implications for precision medicine development in the diagnosis and treatment of AD.

scholarly journals Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit

2021 ◽  
Vol 15 ◽  
Author(s):  
Louis-Philippe Bernier ◽  
Clément Brunner ◽  
Azzurra Cottarelli ◽  
Matilde Balbi
Keyword(s):  
Brain Function ◽  
Energy Demand ◽  
Neurovascular Unit ◽  
Cell Types ◽  
Brain Regions ◽  
Regional Heterogeneity ◽  
Regional Specialization ◽  
Multiple Cell ◽  
Cellular Components ◽  
The Brain

The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.

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