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1.
Ind Psychiatry J ; 32(1): 37-42, 2023.
Article in English | MEDLINE | ID: mdl-37274569

ABSTRACT

Background: Telepsychiatry as a vehicle for delivering mental health services became evident due to outburst of mental health issues during coronavirus disease 2019 (COVID-19) pandemic and it was found useful in providing mental health care while maintaining social distancing norms and lockdown guidelines. Aim: To study clinical profile and sociodemographic profile of patients utilizing telepsychiatry services during COVID-19 pandemic. Materials and Methods: Total 70 old follow-up and 42 new patients were consulted on telepsychiatry, as per Indian Telepsychiatry Operational Guidelines 2020 given by NIMHANS, during 1st and 2nd wave of COVID-19 pandemic from June 2020 to May 2021. Sociodemographic and clinical data was extracted from all patients who utilized our telepsychiatry services in a semi-structured proforma for retrospective analysis using frequency tables. Results: A total of 102 patients benefitted from our telepsychiatry services. Out of which, 66.7% were adults between 21 and 40 years, with slight female preponderance (55.9%) and majority (78.4%) participants living in urban areas. About 70.6% were graduates with 41.2% participants belonging to either private or public service. One-third of the participants were IT professionals. Around 59.8% participants had past history of psychiatric illness and 40.2% had new onset illness. The diagnostic distribution included depressive disorder (28.4%), anxiety disorder (26.4%), psychotic disorder (21.6%) and obsessive compulsive disorder (9.8%) and others (13.8). Conclusion: Telepsychiatry has emerged as an important consultation modality in this COVID-19 pandemic. Its future use seems promising, which will require mental health practitioners to develop their skills while interacting digitally, conducting assessments, and therapy.

2.
J Pediatr Surg ; 58(9): 1715-1726, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37244849

ABSTRACT

OBJECTIVE: To compare the outcomes of patients with multifocal hepatoblastoma (HB) treated at our institution with either orthotopic liver transplant (OLTx) or hepatic resection to determine outcomes and risk factors for recurrence. BACKGROUND: Multifocality in HB has been shown to be a significant prognostic factor for recurrence and worse outcome. The surgical management of this type of disease is complex and primarily involves OLTx to avoid leaving behind microscopic foci of disease in the remnant liver. METHODS: We performed a retrospective chart review on all patients <18 years of age with multifocal HB treated at our institution between 2000 and 2021. Patient demographics, operative procedure, post-operative course, pathological data, laboratory values, short- and long-term outcomes were analyzed. RESULTS: A total of 41 patients were identified as having complete radiologic and pathologic inclusion criteria. Twenty-three (56.1%) underwent OLTx and 18 (43.9%) underwent partial hepatectomy. Median length of follow-up across all patients was 3.1 years (IQR 1.1-6.6 years). Cohorts were similar in rates of PRETEXT designation status identified on standardized imaging re-review (p = .22). Three-year overall survival (OS) estimate was 76.8% (95% CI: 60.0%-87.3%). There was no difference in rates of recurrence or overall survival in patients who underwent either resection or OLTx (p = .54 and p = .92 respectively). Older patients (>72 months), patients with a positive porta hepatis margin, and patients with associated tumor thrombus experienced worse recurrence rates and survival. Histopathology demonstrating pleomorphic features independently associated with worse rates of recurrence. CONCLUSIONS: Through proper patient selection, multifocal HB was adequately treated with either partial hepatectomy or OLTx with comparable outcome results. HB with pleomorphic features, increased patient age at diagnosis, involved porta hepatis margin on pathology, and the presence of associated tumor thrombus may be associated with worse outcomes regardless of the local control surgery offered. LEVEL OF EVIDENCE: III.


Subject(s)
Hepatoblastoma , Liver Neoplasms , Humans , Infant , Hepatoblastoma/surgery , Hepatoblastoma/pathology , Liver Neoplasms/pathology , Retrospective Studies , Hepatectomy/methods , Margins of Excision , Treatment Outcome , Neoplasm Recurrence, Local/pathology
3.
J Pediatr Hematol Oncol ; 44(3): e751-e755, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-34224514

ABSTRACT

Pancreatic angiosarcoma is an exceedingly rare malignancy accounting for <1% of pancreatic neoplasms. A very limited number of pancreatic angiosarcomas have been reported in the literature without any cases described in children. We present the case of a 17-year-old female diagnosed with angiosarcoma of the pancreas following pancreaticoduodenectomy for a pancreatic mass, initially presumed to be a solid pseudopapillary neoplasm of the pancreas. The angiosarcoma was found to have a novel activating internal tandem duplication in the KDR gene (KDR-internal tandem duplication). We discuss the current literature on this disease process. This is the first reported case of pancreatic angiosarcoma in a pediatric patient and the first with an activating KDR-internal tandem duplication.


Subject(s)
Hemangiosarcoma , Pancreatic Neoplasms , Adolescent , Female , Hemangiosarcoma/genetics , Hemangiosarcoma/pathology , Hemangiosarcoma/surgery , Humans , Pancreas/pathology , Pancreas/surgery , Pancreatectomy , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/surgery , Pancreaticoduodenectomy , Vascular Endothelial Growth Factor Receptor-2
4.
Sci Rep ; 9(1): 10431, 2019 07 18.
Article in English | MEDLINE | ID: mdl-31320698

ABSTRACT

Heart failure with preserved ejection fraction (HFpEF) is a major cause of morbidity and mortality, accounting for the majority of heart failure (HF) hospitalization. To identify the most complementary predictors of mortality among clinical, laboratory and echocardiographic data, we used cluster based hierarchical modeling. Using Stanford Translational Research Database, we identified patients hospitalized with HFpEF between 2005 and 2016 in whom echocardiogram and NT-proBNP were both available at the time of admission. Comprehensive echocardiographic assessment including left ventricular longitudinal strain (LVLS), right ventricular function and right ventricular systolic pressure (RVSP) was performed. The outcome was defined as all-cause mortality. Among patients identified, 186 patients with complete echocardiographic assessment were included in the analysis. The cohort included 58% female, with a mean age of 78.7 ± 13.5 years, LVLS of -13.3 ± 2.5%, an estimated RVSP of 38 ± 13 mmHg. Unsupervised cluster analyses identified six clusters including ventricular systolic-function cluster, diastolic-hemodynamic cluster, end-organ function cluster, vital-sign cluster, complete blood count and sodium clusters. Using a stepwise hierarchical selection from each cluster, we identified NT-proBNP (standard hazard ratio [95%CI] = 1.56 [1.17-2.08]) and RVSP (1.37 [1.09-1.78]) as independent correlates of outcome. When adding these parameters to the well validated Get with the Guideline Heart Failure risk score, the Chi-square was significantly improved (p = 0.01). In conclusion, NT-proBNP and RVSP were independently predictive in HFpEF among clinical, imaging, and biomarker parameters. Cluster-based hierarchical modeling may help identify the complementally predictive parameters in small cohorts with higher dimensional clinical data.


Subject(s)
Heart Failure/pathology , Heart Ventricles/pathology , Ventricular Function, Left/physiology , Aged , Biomarkers/metabolism , Diastole/physiology , Echocardiography/methods , Female , Heart Failure/metabolism , Heart Ventricles/metabolism , Hospitalization , Humans , Male , Prognosis , Stroke Volume/physiology
5.
Waste Manag ; 47(Pt A): 40-5, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26303650

ABSTRACT

Biomass is available in many varieties, consisting of crops as well as its residues from agriculture, forestry, and the agro-industry. These different biomass find their way as freely available fuel in rural areas but are also responsible for air pollution. Emissions from such solid fuel combustion to indoor, regional and global air pollution largely depend on fuel types, combustion device, fuel properties, fuel moisture, amount of air supply for combustion and also on climatic conditions. In both economic and environment point of view, gasification constitutes an attractive alternative for the use of biomass as a fuel, than the combustion process. A large number of studies have been reported on a variety of biomass and agriculture residues for their possible use as renewable fuels. Considering the area specific agriculture residues and biomass availability and related transportation cost, it is important to explore various local biomass for their suitability as a fuel. Maharashtra (India) is the mainstay for the agriculture and therefore, produces a significant amount of waste biomass. The aim of the present research work is to analyze different local biomass wastes for their proximate analysis and calorific value to assess their potential as fuel. The biomass explored include cotton waste, leaf, soybean waste, wheat straw, rice straw, coconut coir, forest residues, etc. mainly due to their abundance. The calorific value and the proximate analysis of the different components of the biomass helped in assessing its potential for utilization in different industries. It is observed that ash content of these biomass species is quite low, while the volatile matter content is high as compared to Indian Coal. This may be appropriate for briquetting and thus can be used as a domestic fuel in biomass based gasifier cook stoves. Utilizing these biomass species as fuel in improved cook-stove and domestic gasifier cook-stoves would be a perspective step in the rural energy and environmental sectors. This is important considering that the cleaner fuel like LPG is still not available in rural areas of many parts of the world.


Subject(s)
Biofuels/analysis , Biomass , Waste Management/methods , Garbage , India , Solid Waste/analysis
6.
Med J Malaysia ; 65(3): 227-8, 2010 Sep.
Article in English | MEDLINE | ID: mdl-21939175

ABSTRACT

We describe a patient with multiple myeloma, who initially responded to chemotherapy and went into remission. She presented 10 months later with a right breast lump which was confirmed by core biopsy to be a plasmacytoma. Further treatment with radiotherapy, thalidomide and later second line chemotherapy appeared unsuccessful and she showed rapid disease progression with rising paraproteins and new extramedullary plasmacytoma lesions in the forehead, supraclavicular region, nasopharynx, liver, spleen, pancreas and paraaortic lymph nodes.


Subject(s)
Breast Neoplasms/pathology , Multiple Myeloma/pathology , Neoplasm Recurrence, Local/pathology , Plasmacytoma/pathology , Breast Neoplasms/drug therapy , Breast Neoplasms/radiotherapy , Breast Neoplasms/secondary , Fatal Outcome , Female , Humans , Middle Aged , Multiple Myeloma/drug therapy , Neoplasm Metastasis , Plasmacytoma/radiotherapy , Plasmacytoma/secondary
7.
Med J Malaysia ; 60(2): 237-8, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16114169

ABSTRACT

A patient with duodenal ulcer who developed iatrogenic perforation post endoscopy is presente. We present t is case that was treated successfully treated by jejunal serosal patch.


Subject(s)
Duodenoscopy/adverse effects , Duodenum/injuries , Duodenum/surgery , Iatrogenic Disease , Jejunum/transplantation , Laparotomy/methods , Aged , Duodenal Ulcer/diagnosis , Female , Follow-Up Studies , Humans , Peptic Ulcer Hemorrhage/diagnosis , Rupture/surgery
8.
Appl Microbiol Biotechnol ; 53(5): 610-2, 2000 May.
Article in English | MEDLINE | ID: mdl-10855724

ABSTRACT

The lactone 6-pentyl-alpha-pyrone has a characteristic coconut aroma and is produced by Trichoderma species. A study on the fermentative production of 6-pentyl-alpha-pyrone in both surface and submerged conditions by Trichoderma harzianum was carried out. Maximum concentrations of 455 mg/l and 167 mg/l after 96 h and 48 h of fermentation in surface and submerged conditions, respectively, were obtained without using any additional recovery operations. The resultant yields are higher than those previously reported in the literature, which may be attributable to strain characteristics in combination with the choice of fermentation conditions employed in the present study. Enough scope exists for further improvement in the yields by optimizing the cultural and nutritional parameters.


Subject(s)
Pyrones/metabolism , Trichoderma/metabolism , Biomass , Culture Media , Fermentation , Lactones/metabolism , Trichoderma/growth & development
9.
Dev Biol ; 214(1): 113-27, 1999 Oct 01.
Article in English | MEDLINE | ID: mdl-10491261

ABSTRACT

We have previously identified multipotent neuroepithelial (NEP) stem cells and lineage-restricted, self-renewing precursor cells termed NRPs (neuron-restricted precursors) and GRPs (glial-restricted precursors) present in the developing rat spinal cord (A. Kalyani, K. Hobson, and M. S. Rao, 1997, Dev. Biol. 186, 202-223; M. S. Rao and M. Mayer-Proschel, 1997, Dev. Biol. 188, 48-63; M. Mayer-Proschel, A. J. Kalyani, T. Mujtaba, and M. S. Rao, 1997, Neuron 19, 773-785). We now show that cells identical to rat NEPs, NRPs, and GRPs are present in mouse neural tubes and that immunoselection against cell surface markers E-NCAM and A2B5 can be used to isolate NRPs and GRPs, respectively. Restricted precursors similar to NRPs and GRPs can also be isolated from mouse embryonic stem cells (ES cells). ES cell-derived NRPs are E-NCAM immunoreactive, undergo self-renewal in defined medium, and differentiate into multiple neuronal phenotypes in mass culture. ES cells also generate A2B5-immunoreactive cells that are similar to E9 NEP-cell-derived GRPs and can differentiate into oligodendrocytes and astrocytes. Thus, lineage restricted precursors can be generated in vitro from cultured ES cells and these restricted precursors resemble those derived from mouse neural tubes. These results demonstrate the utility of using ES cells as a source of late embryonic precursor cells.


Subject(s)
Nervous System/embryology , Neurons/cytology , Spinal Cord/embryology , Stem Cells/cytology , Animals , Calcium/metabolism , Cell Differentiation , Cells, Cultured , Culture Media , Epithelial Cells/cytology , Epithelial Cells/physiology , ErbB Receptors/analysis , ErbB Receptors/genetics , Gangliosides/analysis , Immunohistochemistry , Mice , Mice, Inbred C57BL , Nerve Tissue Proteins/analysis , Nerve Tissue Proteins/genetics , Nervous System/cytology , Neural Cell Adhesion Molecules/analysis , Polymerase Chain Reaction , Rats , Spinal Cord/cytology
10.
J Biol Chem ; 274(36): 25455-60, 1999 Sep 03.
Article in English | MEDLINE | ID: mdl-10464276

ABSTRACT

The oligodendrocyte-type-2 astrocyte progenitor cells (precursors of oligodendrocytes and type-2 astrocytes) are an excellent system in which to study differentiation as they can be manipulated in vitro. Maintenance of oligodendrocyte-type-2 astrocyte progenitor cells requires basic fibroblast growth factor, a growth factor whose action normally depends on a heparan sulfate coreceptor. Biochemical analysis revealed a most surprising result: that the oligodendrocyte-type-2 astrocyte progenitors did not synthesize heparan sulfate, the near ubiquitous N-sulfated cell surface polysaccharide, but the chemically related heparin in a form that was almost completely N- and O-sulfated. The heparin was detected in the pericellular fraction of the cells and the culture medium. In contrast the differentiated glial subpopulations (oligodendrocytes and type-2 astrocytes) synthesized typical heparan sulfate but with distinctive fine structural features for each cell type. Thus heparin is a unique differentiation marker in the glial lineage. Previously heparin has been found only in a subset of mature mast cells called the connective tissue mast cells. Its presence within the developing nervous system on a precise population of progenitors may confer specific and essential recognition properties on those cells in relation to binding soluble growth and/or differentiation factors and the extracellular matrix.


Subject(s)
Cell Lineage , Heparin/biosynthesis , Oligodendroglia/cytology , Oligodendroglia/metabolism , Stem Cells/cytology , Animals , Biomarkers , Cell Differentiation , Cells, Cultured , Rats
11.
J Neurobiol ; 38(2): 207-24, 1999 Feb 05.
Article in English | MEDLINE | ID: mdl-10022567

ABSTRACT

To characterize the role of epidermal growth factor (EGF) and fibroblast growth factor (FGF) in regulating neuroepithelial stem cells differentiation, we have examined the expression of FGF, EGF, and their receptors by neuroepithelial (NEP) cells and their derivatives. Our results indicate that undifferentiated NEP cells express a subset of FGF receptor (FGFR) isoforms, but do not express platelet-derived growth factor receptors (PDGFRs) or epidermal growth factor receptor (EGFR). The FGFR pattern of expression by differentiated neuron and glial cells differs from that found on NEP stem cells. FGFR-4 is uniquely expressed on NEP cells, while FGFR-1 is expressed by both NEP cells and neurons, and FGFR-2 is down-regulated during neuronal differentiation. FGFRs present on astrocytes and oligodendrocytes also represent a subset of those present on NEP cells. Expression of FGF and EGF by NEP cells and their progeny was also examined. NEP cells synthesize detectable levels of both FGF-1 and FGF-2, and EGF. FGF-1 and FGF-2 synthesis is likely to be biologically relevant, as cells grown at high density do not require exogenous FGF for their survival and cells grown in the presence of neutralizing antibodies to FGF show a reduction in cell survival and division. Thus, neuroepithelial cells synthesize and respond to FGF, but not to EGF, and are therefore distinct from other neural stem cells (neurospheres). The unique pattern of expression of FGF isoforms may serve to distinguish NEP cells from their more differentiated progeny.


Subject(s)
ErbB Receptors/biosynthesis , Neurons/physiology , Receptors, Fibroblast Growth Factor/biosynthesis , Stem Cells/physiology , Animals , Astrocytes/physiology , Bromodeoxyuridine/pharmacology , Cell Differentiation/physiology , Cell Survival/physiology , Culture Media , Epithelial Cells/metabolism , Epithelial Cells/physiology , Fibroblast Growth Factor 1/biosynthesis , Fibroblast Growth Factor 2/biosynthesis , Immunohistochemistry , Isomerism , Mitogens/pharmacology , Neurons/metabolism , Oligodendroglia/metabolism , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Stem Cells/metabolism
12.
J Neurosci ; 18(19): 7856-68, 1998 Oct 01.
Article in English | MEDLINE | ID: mdl-9742154

ABSTRACT

Neuronal restricted precursors (NRPs) () can generate multiple neurotransmitter phenotypes during maturation in culture. Undifferentiated E-NCAM+ (embryonic neural cell adhesion molecule) immunoreactive NRPs are mitotically active and electrically immature, and they express only a subset of neuronal markers. Fully mature cells are postmitotic, process-bearing cells that are neurofilament-M and synaptophysin immunoreactive, and they synthesize and respond to different subsets of neurotransmitter molecules. Mature neurons that synthesize and respond to glycine, glutamate, GABA, dopamine, and acetylcholine can be identified by immunocytochemistry, RT-PCR, and calcium imaging in mass cultures. Individual NRPs also generate heterogeneous progeny as assessed by neurotransmitter response and synthesis, demonstrating the multipotent nature of the precursor cells. Differentiation can be modulated by sonic hedgehog (Shh) and bone morphogenetic protein (BMP)-2/4 molecules. Shh acts as a mitogen and inhibits differentiation (including cholinergic differentiation). BMP-2 and BMP-4, in contrast, inhibit cell division and promote differentiation (including cholinergic differentiation). Thus, a single neuronal precursor cell can differentiate into multiple classes of neurons, and this differentiation can be modulated by environmental signals.


Subject(s)
Neurons/cytology , Spinal Cord/cytology , Stem Cells/cytology , Trans-Activators , Transforming Growth Factor beta , Animals , Antibodies/pharmacology , Binding, Competitive/immunology , Bone Morphogenetic Protein 2 , Bone Morphogenetic Protein 4 , Bone Morphogenetic Proteins/physiology , Cells, Cultured , Embryonic Induction/physiology , Extracellular Space/chemistry , Extracellular Space/physiology , Female , Fetus/cytology , Hedgehog Proteins , Neural Cell Adhesion Molecules/genetics , Neurons/chemistry , Neurons/drug effects , Neurotransmitter Agents/genetics , Neurotransmitter Agents/pharmacology , Neutralization Tests , Phenotype , Pregnancy , Proteins/immunology , Proteins/metabolism , Rats , Rats, Sprague-Dawley , Signal Transduction/physiology , Stem Cells/chemistry , Stem Cells/drug effects
13.
Biochem Cell Biol ; 76(6): 1051-68, 1998.
Article in English | MEDLINE | ID: mdl-10392716

ABSTRACT

Acquisition of cell type specific properties in the spinal cord is a process of sequential restriction in developmental potential. A multipotent stem cell of the nervous system, the neuroepithelial cell, generates central nervous system and peripheral nervous system derivatives via the generation of intermediate lineage restricted precursors that differ from each other and from neuroepithelial cells. Intermediate lineage restricted neuronal and glial precursors termed neuronal restricted precursors and glial restricted precursors, respectively, have been identified. Differentiation is influenced by extrinsic environmental signals that are stage and cell type specific. Analysis in multiple species illustrates similarities between chick, rat, mouse, and human cell differentiation. The utility of obtaining these precursor cell types for gene discovery, drug screening, and therapeutic applications is discussed.


Subject(s)
Cell Lineage , Neural Crest/embryology , Spinal Cord/embryology , Animals , Cell Differentiation , Cells, Cultured , Gene Expression Regulation, Developmental , Genetic Therapy , Humans , Mice , Models, Biological , Neuroglia/physiology , Rats , Stem Cells/cytology
14.
Neuron ; 19(4): 773-85, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9354325

ABSTRACT

We have identified a neuronal-restricted precursor (NRP) cell that expresses E-NCAM (high polysialic-acid NCAM) and is morphologically distinct from multipotent neuroepithelial (NEP) cells (Kalyani et al., 1997) and spinal glial progenitors (Rao and Mayer-Proschel, 1997). NRP cells self renew over multiple passages in the presence of fibroblast growth factor (FGF) and neurotrophin-3 (NT-3) and differentiate in the presence of retinoic acid and the absence of FGF into postmitotic neurons. NRP cells can also be generated from multipotent E10.5 NEP cells. Clonal analysis shows that NRP cells arise from a NEP progenitor that generates other restricted CNS precursors. The NEP-derived NRPs undergo self renewal and can differentiate into multiple neuronal phenotypes. Thus, a direct lineal relationship exists between multipotential NEP cells and more restricted neuronal precursor cells present in vivo at E13.5 in the spinal cord.


Subject(s)
Epithelial Cells/cytology , Epithelial Cells/physiology , Neural Cell Adhesion Molecule L1 , Neural Cell Adhesion Molecules/biosynthesis , Neuroglia/physiology , Neurons/physiology , Sialic Acids/biosynthesis , Spinal Cord/cytology , Stem Cells/cytology , Stem Cells/physiology , Animals , Astrocytes/cytology , Cell Differentiation , Cells, Cultured , Clone Cells , Embryo, Mammalian , Glial Fibrillary Acidic Protein/biosynthesis , Neuroglia/cytology , Neurons/cytology , Oligodendroglia/cytology , Rats , Rats, Sprague-Dawley , Spinal Cord/embryology , Spinal Cord/physiology , Tubulin/biosynthesis
15.
Dev Biol ; 186(2): 202-23, 1997 Jun 15.
Article in English | MEDLINE | ID: mdl-9205140

ABSTRACT

Adherent cultures of E10.5 rat neuroepithelial cells (NEP cells) from the caudal neural tube require FGF (fibroblast growth factor) and CEE (chick embryo extract) to proliferate and maintain an undifferentiated phenotype in culture. Epidermal growth factor (EGF) does not support E10.5 NEP cells in adherent culture and NEP cells do not form EGF-dependent neurospheres. NEP cells, however, can be grown as FGF-dependent neurospheres. NEP cells express nestin and lack all lineage-specific markers for neuronal and glial sublineages, retain their pleuripotent character over multiple passages, and can differentiate into neurons, astrocytes, and oligodendrocytes when plated on laminin in the absence of CEE. In clonal culture, NEP cells undergo self-renewal and generate colonies that vary in size from single cells to several thousand cells. With the exception of a few single-cell clones, all other NEP-derived clones contain more than one identified phenotype, with over 40% of the colonies containing A2B5, beta-111 tubulin, and GFAP-immunoreactive cells. Thus, NEP cells are multipotent and capable of generating multiple neural derivatives. NEP cells also differentiate into motoneurons immunoreactive for choline acetyl transferase (ChAT) and the low-affinity neurotrophin receptor (p75) in both mass and clonal culture. Double labeling of clones for ChAT and glial, neuronal, or oligodendrocytic lineage markers shows that motoneurons always arose in mixed cultures with other differentiated cells. Thus, NEP cells represent a common progenitor for motoneurons and other spinal cord cells. The relationship of NEP cells with other neural stem cells is discussed.


Subject(s)
Spinal Cord/cytology , Spinal Cord/embryology , Stem Cells/cytology , Animals , Astrocytes/cytology , Cell Differentiation , Cell Separation , Cells, Cultured , Chick Embryo , Choline O-Acetyltransferase/analysis , Epidermal Growth Factor/pharmacology , Epithelial Cells , Fibroblast Growth Factors/pharmacology , Motor Neurons/cytology , Neurons/cytology , Oligodendroglia/cytology , Rats , Rats, Sprague-Dawley , Receptors, Nerve Growth Factor/analysis
16.
Neurobiol Aging ; 18(6): 651-9, 1997.
Article in English | MEDLINE | ID: mdl-9461063

ABSTRACT

Previously, we found that aged rats showed a significant enhancement of hippocampal CA1 place cell spatial specificity, as well as a reduction of hilar place cell spatial specificity, during asymptote performance of a spatial memory task. Because such an age effect was not observed when animals performed a nonspatial task, the present study tested the hypothesis that the different patterns of spatial selectivity observed in memory and nonmemory tests reflected a redistribution of spatial representations that occurred in response to changing task demands. In the present experiment, after animals became familiar with the test environment and motor demands of performance on a radial maze, CA1 and hilar place cells were recorded as they learned a spatial memory task. CA1 place cells recorded from unimpaired old, but not impaired old or young, animals became more spatially selective as animals learned the task. Hilar spatial selectivity for both age groups was not significantly related to choice accuracy. These data support the hypothesis that at least a subpopulation of aged rats may benefit from reorganization of spatial representations in such a way that the normal age-related spatial learning deficit is attenuated.


Subject(s)
Aging/psychology , Hippocampus/physiology , Space Perception/physiology , Animals , Electrodes, Implanted , Hippocampus/cytology , Hippocampus/growth & development , Male , Maze Learning/physiology , Memory/drug effects , Pyramidal Tracts/physiology , Rats , Rats, Inbred F344 , Space Perception/drug effects
17.
Behav Neurosci ; 110(5): 1006-16, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8919003

ABSTRACT

Young and old rats performed on a maze according to a forced-choice and then a spatial memory procedure either in the same or a different environment. Aged rats were slower to learn the spatial memory task when tested in the same, but not in a different, room. One interpretation of this pattern of results is that although old rats learn new rules as quickly as young rats, they show less flexibility with old rules and familiar spatial information. Impaired choice accuracy during asymptote performance suggests poor processing of trial-unique information by old rats. Spatial correlates of hippocampal CA1 and hilar cells varied with task demand: CA1 cells of aged rats showed more spatially selective place fields, whereas hilar cells showed more diffuse location coding during spatial memory, and not forced-choice, tests. Such representational reorganization may reflect a compensatory response to age-related neurobiological changes in hippocampus.


Subject(s)
Aging/physiology , Hippocampus/physiology , Maze Learning/physiology , Mental Recall/physiology , Orientation/physiology , Animals , Association Learning/physiology , Brain Mapping , Evoked Potentials/physiology , Neurons/physiology , Rats , Rats, Inbred F344 , Reaction Time/physiology , Retention, Psychology/physiology , Social Environment
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