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T Casoli

Publications and source records attributed to T Casoli.

At least 19 recordsLinked to original sources
PubMed2006

Structural synaptic remodeling in the perirhinal cortex of adult and old rats following object-recognition visual training.

The ultrastructural features of layer II synapses in the perirhinal cortex of adult (4- to 6-month-old) and old (25- to 27-month-old) rats exposed to a six-session object recognition visual training were investigated by morphometric methods. The comparative analysis showed a higher synaptic numeric density, a lower synaptic average area, and a lower percentage of megasynapses (S > 0.5 microm2) in old trained rats versus controls, and a higher percentage of small (S < 0.15 microm2) junctions in adult trained rats versus controls. The more marked synaptic remodeling underlying memory consolidation in the perirhinal cortex of old rats might reflect a pre-existing lower dynamic status.

Aging↗
PubMed2003

Ethanol-induced decrease of the expression of glucose transport protein (Glut3) in the central nervous system as a predisposing condition to apoptosis: the effect of age.

We measured the effect of chronic ethanol administration on the expression of Glut3 in the cerebellum and hippocampus of adult and old rats. Glut3 expression significantly decreased in aging, in ethanol-treated rats vs. age-matched controls, and in adult- vs. old ethanol-treated rats. These findings lend consistent support to the hypothesis that disturbances of glucose metabolism due to ethanol may constitute an unfavorable condition predisposing to neuronal death.

Aging↗
PubMed2002

Fabricated hyalS micropatterns and surface guidance of NCTC 2544 continuous cell line: an in vitro study.

Surface topography is important in establishing tissue organisation adjacent to implants, smooth surfaces generally being associated with fibrous encapsulation. By virtue of its large hydrated molecular volume and its capacity to form molecular matrix, hyaluronic acid can expand the interfibrillar collagen spaces to allow the movement of cells, although it can also hamper their locomotion. Low molecular-weight hyaluronan can also stimulate cell proliferation, especially at low concentrations. The aim of the present work was to evaluate in vitro the growth and migratory behaviour of NCTC 2544 keratinocytes cultured on different materials microstructured with hyaluronic acid or sulfated hyaluronic acid to assess the possibility of using these devices in the repair process of soft tissues. Ultrastructural morphological analyses, morphometric evaluations and detection of cytoskeletal elements were performed. Our observations provide evidence that micrometer-size parallel grooves of hyaluronic acid can influence cell growth behaviour since cells seeded onto the microstructured substrate arranged themselves according to a shape and an orientation that clearly reflected the chemotropism exerted on them by the two forms of acid. These data also highlight the importance of accurate microtexture fabrication. We intend to follow up these in vitro studies with in vivo experimental applications using PET and gelatin substrates structured with HyalS to evaluate wound healing responses, and to extend our investigations of the cytoskeletal modifications induced by different microstructures.

Adjuvants, Immunologic↗
PubMed2001

Age-related effects of moderate alcohol consumption on GAP-43 levels in rat hippocampus.

The effects of moderate intake of ethanol and ageing were investigated on the levels of the growth-associated protein GAP-43, whose expression has been used as an indicator of axonal growth during development, regeneration and remodelling of synaptic connections. Groups of female Wistar rats (12 and 24 months of age), were alcohol-fed for one month while age-matched control groups received an isocaloric diet. A quantitative evaluation of GAP-43 was performed in hippocampus and in hippocampal selected areas in view of the vulnerability of this complex to alcohol aggression by means of two different methods, namely Western blot analysis and immunohistochemistry. While the former measures total extractable GAP-43, the latter allows visualisation of in situ changes in topographical distribution of GAP-43. Western blot analysis revealed an age-dependent reduction (-47%) and an ethanol-associated increase (81%) of GAP-43 demonstrated only in the old group. Conversely, quantitative immunohistochemistry of GAP-43 in the entire hippocampus showed a non-significant ethanol-related decrement in 24-month-old rats (-30%), although the age-dependent reduction was confirmed. Ageing was associated with a decrement of GAP-43 immunostaining in CA3 stratum radiatum (CA3) and in inner molecular layer of dentate gyrus (IML). Treatment determined a decrease of GAP-43 immunostaining in adult rat CA3 and IML and no change in CA1 stratum radiatum (CA1). Our results suggest that immunohistochemistry evaluation underestimates GAP-43 levels in ethanol-treated animals possibly as a consequence of conformational changes induced by alcohol, resulting in non-targeting of the specific antibody. Western blot analysis demonstrate that although there is a reduction of GAP-43 levels in hippocampus of aged rats, this structure retain a remarkable potential to compensate for ethanol toxicity during ageing.

Aging↗
PubMed2001

Quantitative cytochemical mapping of mitochondrial enzymes in rat cerebella.

Mitochondrial metabolic competence, defined as the organelle's capacity to provide adequate amounts of ATP in due time, appears to constitute an important determinant in several biological processes and pathological conditions. Thus, the assessment of the metabolic efficiency of the mitochondrial population in a given tissue area or cellular compartment may provide clues to identifying alterations of the cellular bioenergetic machinery, which may constitute a predisposing condition leading to impaired organ and system functions. In the cerebellar cortex of adult rats, the activities of the enzymes cytochrome oxidase (COX) and succinic dehydrogenase (SDH) were, respectively, evidenced by means of the diaminobenzidine and copper ferrocyanide preferential cytochemical techniques. At the electron microscope, the activities of these two key molecules of the respiratory chain were clearly visualised as dark precipitates at the inner mitochondrial membrane sites where COX and SDH are located. By means of the disector method, unbiased mitochondrial samplings were carried out to measure: the number of mitochondria/microm(3) of tissue (numeric density: Nv); the mitochondrial volume fraction/microm(3) of tissue (volume density: Vv) and the average mitochondrial volume (V) both on COX- and SDH-positive organelles in the cerebellar glomeruli and Purkinje cells, respectively. The ratio R (total area of the precipitates due either to COX or SDH activity within the single mitochondrion/area of the same organelle) was also evaluated to get information on the enzyme activity related to mitochondrial size.The documented accumulation of mutant mitochondrial DNA particularly in postmitotic cells results in a marked heteroplasmy (mixtures of normal and mutated genomes) at mitochondrial and cellular levels, thus the cellular potential for energy production is demanded to a mosaic of organelles with different functional capabilities. Assessment of the mitochondrial mosaic outline by means of quantitative cytochemistry of key enzymes of the respiratory chain, such as COX and SDH, may allow for the morphofunctional metabolic mapping of mitochondrial efficiency in discrete cellular or tissue compartments.

Animals↗
PubMed2001

Quantitative immunohistochemistry of glucose transport protein (Glut3) expression in the rat hippocampus during aging.

Immunohistochemistry of Glut3 (45 kD), an integral membrane peptide mediating the transport of glucose in neurons, was carried out in the hippocampus of 3- and 28-month-old rats to assess the effect of age on energy metabolism. Free-floating sections of fixed-frozen hippocampi were processed for quantitative immunohistochemistry of Glut3. A rabbit affinity-purified antibody identified Glut3 immunoreactivity. Glut3 staining was intense in neuropil, axons, and dendrites, whereas nerve cell bodies were unstained. With aging, Glut3 reactivity was significantly decreased in the inner molecular layer of the hippocampal dentate gyrus (-46%) and the mossy fibers of the CA3 sector (-34%), whereas the stratum radiatum of CA1 did not show any difference due to age. These data document an age-dependent decrease in Glut3 expression in discrete areas of rat hippocampus. Glut3 constitutes the predominant glucose transporter in neurons and is found abundantly in regions with high synaptic density characterized by frequent bursts of function-adequate metabolic activity. Our findings therefore lend further support to the critical role of an impaired metabolism in age-related brain dysfunctions and disease.(J Histochem Cytochem 49:671-672, 2001)

Aging↗
PubMed2001

Distribution of map2 in hippocampus and cerebellum of young and old rats by quantitative immunohistochemistry.

The microtubule-associated protein MAP2 is a cytoskeletal protein that plays a regulatory role in neuronal plasticity and in maintaining the morphology of differentiated neurons. MAP2 distribution was assessed in hippocampus and cerebellum of young and old rats by quantitative immunohistochemistry. In old vs young rats, densitometric analysis showed a significant decrease of MAP2 immunoreactivity in the hippocampus CA1 field (-93%), whereas no difference was found in cerebellar MAP2 distribution. These preliminary data suggest that in areas of the brain involved in memory acquisition and consolidation, MAP2-dependent neuroplasticity and structural integrity are significantly decreased in aging.

Aging↗
PubMed2001

Mapping of mitochondrial metabolic competence by cytochrome oxidase and succinic dehydrogenase cytochemistry.

To map the mitochondrial capacity to provide adenosine triphosphate (ATP), the activities of cytochrome oxidase (COX) and succinic dehydrogenase (SDH) were respectively evidenced by diaminobenzidine (DAB) and copper ferrocyanide cytochemical techniques in the cerebellar cortex of adult rats. Sampling of the positive mitochondria was carried out by the disector procedure. The ratio (R) overall area of the precipitates due to COX activity within the single mitochondrion/area of the same organelle was automatically calculated to estimate enzyme activity vs mitochondrial size. The number of SDH-positive mitochondria/microm(3) of tissue (numeric density, Nv) was morphometrically calculated. Cytochemistry of key enzymes of the respiratory chain enables measurement of the actual capacity of individual mitochondria to provide ATP. This quantitative estimation allows morphofunctional mapping of the mitochondrial metabolic competence in discrete tissue and/or cellular compartments. (J Histochem Cytochem 49:1191-1192, 2001)

Animals↗
PubMed2001

Cellular distribution of GAP-43 mRNA in hippocampus and cerebellum of adult rat brain by in situ RT-PCR.

The growth-associated protein GAP-43 is a presynaptic membrane phosphoprotein that plays a key role in guiding the growth of axons and in modulating the formation of new synapses. To identify the cells that synthesize GAP-43 mRNA, we applied direct in situ reverse transcription-polymerase chain reaction (in situ RT-PCR) in cerebellum and hippocampus of adult rat brain. In situ RT-PCR revealed GAP-43 mRNA in cerebellar granule cells, in Purkinje cells and in some interneurons of the molecular layer. Previous in situ hybridization studies had demonstrated a dense label throughout the granular layer of the cerebellar cortex but no labeling of other cerebellar neurons. Hippocampal cells showing distinct GAP-43 mRNA signal after in situ RT-PCR were CA1 and CA3 pyramidal neurons, CA4 hilar cells, and dentate gyrus granule cells, whereas in situ hybridization studies had detected GAP-43 mRNA only in CA3 and CA1 pyramidal neurons. Our data indicate that GAP-43 mRNA is widely distributed, suggesting that many cell types are potentially involved in synaptic plasticity events. (J Histochem Cytochem 49:1195-1196, 2001)

Animals↗
PubMed1999

Quantitation of intraplatelet Ca++ deposits as a potential marker of senility.

OBJECTIVE: To perform a morphometric evaluation of calcium deposits in human platelets as a quantitative procedure to seek a potential marker of senility in a peripheral cellular model. STUDY DESIGN: In human blood samples from middle-aged, healthy volunteers, the intraplatelet calcium content was cytochemically evidenced by the oxalatepyroantimonate (OPA) reaction. The number and area of OPA aggregates per square micrometer of total sampled area, the area of the deposits per square micrometer of platelet surface and the percentage of positive platelets were the ultrastructural features calculated by computer-assisted image analysis. RESULTS: OPA precipitates were easily identified in all the samples evaluated. The area of OPA deposits per square micrometer of platelet surface was rather constant not only among the measurements performed on the same sample but also comparing the different subjects analyzed. Other OPA deposit features showed higher variabilities; thus, to obtain a representative sample from each patient, several measurements had to be carried out. CONCLUSION: Quantitation of calcium deposits may be of help in evidencing increased Ca++ sequestering activity by platelets, supposedly due to altered calcium homeostasis. The OPA cytochemical procedure visualizes millimolar quantities of Ca++ ions; thus, only high calcium concentration sites (granules) can be detected by morphometric methods.

Aging↗
PubMed1998

Quantitative cytochemistry of succinic dehydrogenase activity in rat mitochondria.

OBJECTIVE: To set up a computer-assisted morphometric procedure to cytochemically measure the activity of succinic dehydrogenase (SDH). STUDY DESIGN: In rat mitochondria from Purkinje cell perikarya and frozen muscle samples, SDH activity was selectively evidenced by the copper ferrocyanide method. On the SDH-positive organelles we measured the following parameters: number of mitochondria per cubic micrometer (numeric density [Nv]), volume fraction of organelles per cubic micrometer (volume density [Vv]), average mitochondrial volume (V) and intramitochondrial area density of the SDH reaction (area of the precipitates/total mitochondrial area [R]). RESULTS: In both fresh Purkinje cells and frozen muscle cells the positive organelles were sharply evident. By considering Vv, Nv and V altogether in a given experimental group, a reliable evaluation of the morphologic rearrangements of the cellular metabolic hardware can be obtained. Measurements of R provides information on the functional efficiency of each organelle. CONCLUSION: Quantitation of SDH-positive mitochondria is closely associated with the amount of enzyme molecules present and active within the organelles. Thus, quantitative assessment of the copper ferrocyanide reaction contributes to the evaluation of mitochondrial metabolic competence.

Animals↗
PubMed1996

Neuronal plasticity in aging: a quantitative immunohistochemical study of GAP-43 distribution in discrete regions of the rat brain.

Age-related changes in neuroplasticity have been investigated considering the neuronal growth-associated protein GAP-43 as a marker of nerve cell structural adaptive capabilities. We carried out a quantitative immunohistochemical study on the distribution of GAP-43 in the molecular layer of the cerebellar cortex, in the inner molecular layer of the hippocampal dentate gyrus, in the stratum radiatum of the CA1 region, in layer 1 of the cingulate cortex and in the nerve fiber layer of the main olfactory bulb of 3-, 18- and 31-month-old Wistar rats. A decrease of GAP-43 immunoreactivity was observed in the old rats in comparison with the adult animals in all the 5 areas analyzed, although these variations were only statistically significant in the dentate gyrus, cingulate cortex and olfactory bulb. In these latter zones, GAP-43 immunolabeling is reduced by 54, 42 and 38%, respectively, in the old versus the adult group. Comparing these data with the age-dependent decrease of neuron density innervating the areas investigated, we support the hypothesis that the decline of GAP-43 observed in old animals documents a consistent reduction of axon plasticity in the inner molecular layer of the dentate gyrus and in layer 1 of the cingulate cortex. These results suggest an important role of GAP-43 as a marker of age-dependent deterioration of synaptic plasticity, especially in those areas of the brain involved in memory and emotional behavior.

Aging↗
PubMed1996

Deterioration threshold of synaptic morphology in aging and senile dementia of Alzheimer's type.

OBJECTIVE: To search for a deterioration threshold of synaptic ultrastructure in physiologic aging and senile dementia of Alzheimer's type (SDAT). STUDY DESIGN: The numerical density (Nu), average area (S) and surface density (Su) of the synaptic contact zones were investigated in the hippocampus and cerebellum from adults, elderly and SDAT patients by means of computer-assisted morphometry. RESULTS: The Nu and surface Su densities of the synapses decreased while the size of S enlarged in elderly and SDAT patients vs. the adults. By plotting Nu vs. S, the adult group showed a very high percentage of small junctions. In contrast, elderly and dementia patients demonstrated two overlapping populations of enlarged contacts. In SDAT the synapse-to-neuron ratio was decreased by 48% in the hippocampus and by 56% in the cerebellum. CONCLUSION: Our findings support the concept that the degeneration of synaptic contacts per se should be considered a crucial step in the progression of senile dementia, but the identification of a discrete deterioration threshold of synaptic morphology between aging and SDAT is not feasible at present.

Aged↗
PubMed1994

Dynamic morphology of the synaptic junctional areas during aging: the effect of chronic acetyl-L-carnitine administration.

The ultrastructural features of hippocampal synaptic contact zones have been investigated by means of computer-assisted morphometry in rats of 6, 12 and 22 months of age and in age-matched animals chronically treated with ALCAR at a daily dose of 50 mg/100 g body weight from the age of 1 month up to the day of sacrifice. The number of synapses/microns 3 (Nv), the average size of the junctional areas (S) and the total area of the synaptic contact zones/microns 3 (Sv) were measured in tissue samples stained by means of the ethanol phosphotungstic acid (E-PTA) preferential technique for synaptic membranes. In control animals Nv was constant between 6 and 12 months of age, but significantly decreased in 22-month-old rats; S did not show significant differences due to age; Sv was unchanged between 6 and 12 months, but it decreased significantly in the old animals. In ALCAR treated rats Nv increased and S decreased significantly vs. Age-matched controls. Sv showed a lifespan constancy among the groups of age analysed. In ALCAR treated rats the number of contact areas smaller than 0.08 micron 2 increased by 18, 9 and 10% at 6, 12 and 22 months of age, respectively. ALCAR administration resulted in a lifespan modulation of synaptic structural dynamics. A proper metabolism at nerve terminals is accounted to play a crucial role in synaptic remodelling potential: on the basis of current research data, it is suggested that ALCAR may improve neuronal bioenergetic mechanisms.

Acetylcarnitine↗