Schizophrenia: A Neuropathological Perspective

1991 ◽  
Vol 158 (1) ◽  
pp. 8-17 ◽  
Author(s):  
G. W. Roberts
Keyword(s):  
Brain Development ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Structural Changes ◽  
Clinical Symptoms ◽  
Association Cortex ◽  
Minor Role ◽  
Normal Brain ◽  
Genetic Mechanisms ◽  
A Minor

It is probable that all schizophrenics have abnormalities in the medial temporal lobe, which differ in degree but not in kind. The structures of the medial temporal lobe are believed to have a crucial role in the integration and processing of the output from the association cortex. Dysfunction of this system could result in the clinical symptoms that form the core of the schizophrenia syndrome. The structural differences appear to fit the profile of a disturbance in the normal pattern of brain development. The asymmetrical patterns of normal brain development explain how such a disturbance simultaneously affecting both hemispheres could, disproportionately, affect the left (dominant) hemisphere. Epidemiological and pathological evidence points to aberrant genetic mechanisms as being the cause of the developmental anomaly in the majority of cases; environmental factors probably play a minor role. Despite the great progress made in solving the enigma of the structural changes in the brains of schizophrenics, the cause(s) of the changes – the aberrant genetic mechanism controlling brain development – may prove difficult to define.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

scholarly journals Novel ex vivo MRI atlas of the medial temporal lobe can be used to characterize structural changes due to Alzheimer’s disease pathology

2020 ◽  
Vol 16 (S4) ◽  
Author(s):  
Sadhana Ravikumar ◽  
Laura Wisse ◽  
Long Xie ◽  
Ranjit Ittyerah ◽  
Sandhitsu R. Das ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Structural Changes ◽  
Ex Vivo

Intracranial Recordings Demonstrate Both Cortical and Medial Temporal Lobe Engagement in Visual Search in Humans

2021 ◽  
pp. 1-29
Author(s):  
S. J. Katarina Slama ◽  
Richard Jimenez ◽  
Sujayam Saha ◽  
David King-Stephens ◽  
Kenneth D. Laxer ◽  
...  
Keyword(s):  
Visual Search ◽  
Frontal Cortex ◽  
Temporal Lobe ◽  
Medial Temporal Lobe ◽  
Association Cortex ◽  
Subcortical Structures ◽  
Spatiotemporal Resolution ◽  
Activity Increase ◽  
Anatomical Space ◽  
Intracranial Recordings

Abstract Visual search is a fundamental human behavior, providing a gateway to understanding other sensory domains as well as the role of search in higher-order cognition. Search has been proposed to include two component processes: inefficient search (search) and efficient search (pop-out). According to extant research, these two processes map onto two separable neural systems located in the frontal and parietal association cortices. In this study, we use intracranial recordings from 23 participants to delineate the neural correlates of search and pop-out with an unprecedented combination of spatiotemporal resolution and coverage across cortical and subcortical structures. First, we demonstrate a role for the medial temporal lobe in visual search, on par with engagement in frontal and parietal association cortex. Second, we show a gradient of increasing engagement over anatomical space from dorsal to ventral lateral frontal cortex. Third, we confirm previous intracranial work demonstrating nearly complete overlap in neural engagement across cortical regions in search and pop-out. We further demonstrate pop-out selectivity, manifesting as activity increase in pop-out as compared to search, in a distributed set of sites including frontal cortex. This result is at odds with the view that pop-out is implemented in low-level visual cortex or parietal cortex alone. Finally, we affirm a central role for the right lateral frontal cortex in search.

Development and plasticity of the neural circuitry underlying visual recognition memory

1995 ◽  
Vol 73 (9) ◽  
pp. 1364-1371 ◽  
Author(s):  
Maree J. Webster ◽  
Leslie G. Ungerleider ◽  
Jocelyne Bachevalier
Keyword(s):  
Recognition Memory ◽  
Temporal Lobe ◽  
Visual Memory ◽  
Medial Temporal Lobe ◽  
Visual Recognition ◽  
Association Cortex ◽  
Subcortical Structures ◽  
Cortical Areas ◽  
Visual Recognition Memory ◽  
Area Te

In adult monkeys, visual recognition memory, as measured by the delayed nonmatching to sample (DNMS) task, requires the interaction between inferior temporal cortical area TE and medial temporal lobe structures (mainly the entorhinal and perirhinal cortical areas). Ontogenetically, monkeys do not perform at adult levels of proficiency on the DNMS task until 2 years of age. Recent studies have demonstrated that this protracted development of visual recognition memory is due to an immaturity of the association areas of the neocortex rather than the medial temporal lobe. For example, lesions of the medial temporal lobe structures in infancy or in adulthood yield profound and permanent visual recognition loss, indicating that the medial temporal lobe structures operate early in life to sustain visual memory. In contrast, early lesions of area TE, unlike late lesions, result in a significant and long-lasting sparing of visual memory ability. Further evidence for neocortical immaturity is provided by studies of the development of opiatergic and cholinergic receptors, of the maturation of metabolic activity, and of the connectivity between inferior temporal areas TE and TEO and cortical and subcortical structures. Together these results indicate greater compensatory potential after neonatal cortical than after neonatal medial temporal removals. In support of this view, early damage to area TE leads to the maintenance of normally transient projections as well as to reorganization in cortical areas outside the temporal lobe. In addition, lesion studies indicate that, during infancy, visual recognition functions are widely distributed throughout many visual association areas but, with maturation, these functions become localized to area TE. Thus, the maintenance of exuberant projections together with reorganization in other cortical areas of the brain could account for the preservation of visual memories in monkeys that have had area TE removed in infancy.Key words: limbic structures, association cortex, amygdala, transient connections, compensatory potential.

scholarly journals Mechanisms of development of temporal lobe epilepsy: clinical and experimental studies

2002 ◽  
Vol XXXIV (1-2) ◽  
pp. 51-59
Author(s):  
O. P. Balykova ◽  
N. P. Shikhanov ◽  
V. S. Inozemtseva ◽  
A. A. Sosunov ◽  
G. McKhann ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Limbic System ◽  
Medial Temporal Lobe ◽  
Structural Changes ◽  
Hippocampal Sclerosis ◽  
Experimental Studies ◽  
Temporal Cortex ◽  
Epileptic Seizures ◽  
Clinical Effectiveness

Among the many forms of epilepsy, one of the most studied is epilepsy of the temporal lobe (temporal lobe epilepsy) associated with the pathology of the limbic system, and especially the hippocampus. Sections of the limbic system are the source of epileptic seizures in this form of the disease, which is confirmed by electroencephalographic data, including those obtained using embedded electrodes [81], and the clinical effectiveness of surgery. Removal of certain parts of the medial temporal cortex, including part of the hippocampus, can heal or reduce the frequency and severity of seizures [92]. On the basis of structural changes, two main types of epilepsy of the temporal lobe are distinguished: 1) with the presence of a volumetric process (tumor, congenital pathology, blood vessel aneurysm, hemorrhage) affecting the limbic system; 2) without the presence of clearly verified volumetric changes in the medial temporal lobe [23]. In the latter case, the only structural manifestation of temporal lobe epilepsy is hippocampal sclerosis. The name reflects the most striking morphological manifestations of the disease - the loss of neurons primarily in the CA1 and CA3 zones of the horn of the ammonia and the development of replacement gliosis. Intravital brain imaging using functional positron emission tomography, magnetic resonance imaging, and magneto-encephalography confirms changes in the hippocampus in temporal lobe epilepsy, usually in the form of a decrease in its volume [60]. There is also a positive correlation between intravital structural and biochemical (in particular, the number of AMPA-A receptors and the intensity of absorption of F-fluoro-2-deoxy-D-glucose) changes in the sclerosed hippocampus and data from the study of surgical material [75].

Charge distributions and chemical effects. XXVII. Molecular energies of carbonyl compounds and ethers, a calculation involving the charges of the bond-forming atoms

1982 ◽  
Vol 60 (6) ◽  
pp. 792-800 ◽  
Author(s):  
S. Fliszár ◽  
M. T. Béraldin
Keyword(s):  
Carbonyl Compounds ◽  
Structural Changes ◽  
Minor Role ◽  
Electronic Charge ◽  
Average Deviation ◽  
Bond Forming ◽  
Chemical Effects ◽  
Coulomb Type ◽  
Individual Bond ◽  
A Minor

Energy calculations are presented for carbonyl compounds and ethers by applying the equation εij = εij0 + aijΔqi + ajiΔqj which describes individual bond contributions in terms of electronic charge increments Δq at the bond-forming atoms i and j, relative to atomic charges in selected reference bonds with energies εij0. At a molecular level, the sum ΣiΣjaijΔqi accounts for virtually the entire energy variations due to charge redistributions accompanying isodesmic structural changes. Coulomb-type interactions between nonbonded atoms play only a minor role in that respect. Using charges derived from 13C and 17O nmr shift-charge correlations, calculated and experimental energies agree within 0.16 kcal/mol (average deviation).

scholarly journals Comparing the backfilling of mesoporous titania thin films with hole conductors of different sizes sharing the same mass density

IUCrJ ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Raphael S. Märkl ◽  
Nuri Hohn ◽  
Emanuel Hupf ◽  
Lorenz Bießmann ◽  
Volker Körstgens ◽  
...  
Keyword(s):  
Thin Films ◽  
Small Molecule ◽  
Structural Changes ◽  
Mass Density ◽  
Grazing Incidence ◽  
Minor Role ◽  
Mesoporous Titania ◽  
Photovoltaic Devices ◽  
A Minor

Efficient infiltration of a mesoporous titania matrix with conducting organic polymers or small molecules is one key challenge to overcome for hybrid photovoltaic devices. A quantitative analysis of the backfilling efficiency with time-of-flight grazing incidence small-angle neutron scattering (ToF-GISANS) and scanning electron microscopy (SEM) measurements is presented. Differences in the morphology due to the backfilling of mesoporous titania thin films are compared for the macromolecule poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b′]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] (PTB7-Th) and the heavy-element containing small molecule 2-pinacolboronate-3-phenylphenanthro[9,10-b]tellurophene (PhenTe-BPinPh). Hence, a 1.7 times higher backfilling efficiency of almost 70% is achieved for the small molecule PhenTe-BPinPh compared with the polymer PTB7-Th despite sharing the same volumetric mass density. The precise characterization of structural changes due to backfilling reveals that the volumetric density of backfilled materials plays a minor role in obtaining good backfilling efficiencies and interfaces with large surface contact.

Advocacy in the New World of Managed Care

1997 ◽  
Vol 78 (1) ◽  
pp. 84-94 ◽  
Author(s):  
Robert Sunley
Keyword(s):  
Managed Care ◽  
Large Scale ◽  
Structural Changes ◽  
Driving Forces ◽  
System Level ◽  
Standards Of Care ◽  
Minor Role ◽  
Consumer Empowerment ◽  
Recent Emergence ◽  
A Minor

With the recent emergence of large-scale health care companies, advocacy's role within the system has been reduced. Already occupying only a minor role in case management (itself partly subsumed into the system), advocacy efforts to help individuals and to make structural changes at the system level run against the driving forces of managed care–cost containment and profit making. Practitioners within the managed-care system may be able to carry out some case-and-cause advocacy within the limits of company requirements and possible job jeopardy. Greater efforts will have to come from outside groups focusing on broad issues, including patients' rights; standards of care; consumer empowerment; outside evaluations; maldistribution of physicians and other personnel; protection against lowering of quantity, type, and quality of services; and training of managed care personnel.

scholarly journals Patterns of coordinated cortical remodeling during adolescence and their associations with functional specialization and evolutionary expansion

2017 ◽  
Vol 114 (13) ◽  
pp. 3527-3532 ◽  
Author(s):  
Aristeidis Sotiras ◽  
Jon B. Toledo ◽  
Raquel E. Gur ◽  
Ruben C. Gur ◽  
Theodore D. Satterthwaite ◽  
...  
Keyword(s):  
Brain Development ◽  
Large Scale ◽  
Nonnegative Matrix ◽  
Higher Order ◽  
Rapid Expansion ◽  
Small Samples ◽  
Association Cortex ◽  
Functional Specialization ◽  
Normal Brain ◽  
Behavioral Repertoire

During adolescence, the human cortex undergoes substantial remodeling to support a rapid expansion of behavioral repertoire. Accurately quantifying these changes is a prerequisite for understanding normal brain development, as well as the neuropsychiatric disorders that emerge in this vulnerable period. Past accounts have demonstrated substantial regional heterogeneity in patterns of brain development, but frequently have been limited by small samples and analytics that do not evaluate complex multivariate imaging patterns. Capitalizing on recent advances in multivariate analysis methods, we used nonnegative matrix factorization (NMF) to uncover coordinated patterns of cortical development in a sample of 934 youths ages 8–20, who completed structural neuroimaging as part of the Philadelphia Neurodevelopmental Cohort. Patterns of structural covariance (PSCs) derived by NMF were highly reproducible over a range of resolutions, and differed markedly from common gyral-based structural atlases. Moreover, PSCs were largely symmetric and showed correspondence to specific large-scale functional networks. The level of correspondence was ordered according to their functional role and position in the evolutionary hierarchy, being high in lower-order visual and somatomotor networks and diminishing in higher-order association cortex. Furthermore, PSCs showed divergent developmental associations, with PSCs in higher-order association cortex networks showing greater changes with age than primary somatomotor and visual networks. Critically, such developmental changes within PSCs were significantly associated with the degree of evolutionary cortical expansion. Together, our findings delineate a set of structural brain networks that undergo coordinated cortical thinning during adolescence, which is in part governed by evolutionary novelty and functional specialization.

scholarly journals Coupled ripple oscillations between the medial temporal lobe and neocortex retrieve human memory

Science ◽  
2019 ◽  
Vol 363 (6430) ◽  
pp. 975-978 ◽  
Author(s):  
Alex P. Vaz ◽  
Sara K. Inati ◽  
Nicolas Brunel ◽  
Kareem A. Zaghloul
Keyword(s):  
Human Brain ◽  
Temporal Lobe ◽  
Verbal Memory ◽  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Direct Evidence ◽  
Human Memory ◽  
Association Cortex ◽  
Temporal Association ◽  
Neural Representations

Episodic memory retrieval relies on the recovery of neural representations of waking experience. This process is thought to involve a communication dynamic between the medial temporal lobe memory system and the neocortex. How this occurs is largely unknown, however, especially as it pertains to awake human memory retrieval. Using intracranial electroencephalographic recordings, we found that ripple oscillations were dynamically coupled between the human medial temporal lobe (MTL) and temporal association cortex. Coupled ripples were more pronounced during successful verbal memory retrieval and recover the cortical neural representations of remembered items. Together, these data provide direct evidence that coupled ripples between the MTL and association cortex may underlie successful memory retrieval in the human brain.

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