G Macchi

Catholic University of the Sacred Heart , Roma, Latium, Italy

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Publications (114)204.38 Total impact

  • Gabriella Marini · Roberto Giglio · Giorgio Macchi · Mauro Mancia
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    ABSTRACT: The role of the nucleus reticularis thalami in spike-wave discharges in rats with genetic absence epilepsy has already been demonstrated. This study further investigated the role of the nucleus reticularis thalami in paroxysmal synchronizations in Sprague-Dawley rats; this strain shows no propensity to epileptic activity. Electroencephalographic patterns were followed in chronically implanted, unrestrained rats. After both electrolytic and chemical unilateral lesions, stereotaxically placed in the anterolateral sectors of this nucleus (verified post mortem), abnormal electroencephalographic rhythms (high-voltage polyspikes and spike-wave complexes) were recorded from the frontoparietal cortex, primarily in the contralateral hemisphere. Stereotyped discharges at 3 Hz developed progressively from multiple spikes within the alpha frequency range through the lengthening of the wave component. The excessive synchronized activity recorded from the intact hemisphere was of greater amplitude and occurred slightly earlier than from the lesioned hemisphere. These EEG patterns were associated with behavioural manifestations closely resembling those seen during absence seizures in humans. Bilateral lesions did not induce paroxysmal activity, both hemispheres being characterized by dominant delta/theta activity without signs of EEG-synchronized sleep. The seizures may thus have been due to disinhibition of the contralateral reticularis nucleus, recently shown to project to the reticularis nucleus of the other side in rats. This working hypothesis is supported by callosal cuts. The results indicate that the reticular neurons exert a control over neocortical paroxysmal activity even in animals which do not present genetic absence epilepsy.
    No preview · Article · Apr 2006 · European Journal of Neuroscience
  • C Masullo · G Macchi
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    ABSTRACT: Human spongiform transmissible encephalopathies (TSE) are a group of neurodegenerative diseases caused by a transmissible not yet recognized agent; their distinctive neuropathological features are astrocytosis, spongiform lesions of the neuropil, neuronal loss and occasionally amyloid plaques in the cortical and subcortical gray matter. TSE are biochemically characterized by the deposition in the nervous system of an amyloid-type protein, PrPres derived from the post-translational modification of a normal protein, PrPsen. The expression of this protein is controlled by the PRNP gene mapped on chromosome 20 in man. A number of point mutations of the PRNP gene have been described in the familial forms of these TSE. Some of these mutations have been associated with differences in the phenotypic expression of the disease. This study was designed to verify whether it was possible to identify a selective phenotype depending upon a given PRNP modified genotye; for this purpose, a group of familial TSE cases (CJD 210ILE, CJD 201LYS, FFI 178ASN) were selected and their neuropathological profiles have been compared with those of a large series of sporadic CJD cases. No significant differences were found between the topography and severity of lesions in the cerebral cortex, cerebellum, hippocampus, basal ganglia and thalamus between the two groups. Two differences were found: the clinical duration of the disease which appeared significantly (p = 0.02) shorter in the 210ILE-mutated cases compared to that of non-mutated sporadic cases. The highly selective vulnerability of thalamus in FFI showing a severe pathology especially in its dorso-medial part in comparison with that of the sporadic CJD cases. The results of this study confirm that the different polymorphism at codon 129 of the PRNP gene, which could be involved in the structural "domains" of human PrP, might modulate the pathological phenotype of TSE.
    No preview · Article · Jan 2001 · Clinical neuropathology
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    ABSTRACT: Creutzfeldt-Jakob disease (CJD) and other transmissible spongiform encephalopathies (TSEs) are characterised by the accumulation of a pathological conformer of PrP, named PrPsc. Molecular weight and glycosylation of the protease-resistant core of PrPsc (PrP27-30) are heterogeneous in different forms of TSEs. We analysed PrP27-30 glycotypes in a large number of TSE-affected patients: 50 sporadic CJD (sCJD), 1 iatrogenic CJD, 1 Gerstmann-Sträussler-Scheinker syndrome (GSS) with the Pro102Leu mutation of PrP, 3 familial CJD (fCJD) with the Glu200Lys mutation and, for the first time, 7 fCJD with the Val210ll3e mutation. All patients were screened for the polymorphic codon 129 of the PrP gene. PrP27-30 deglycosylation and PrPsc immunohistochemistry were performed in selected cases. We found that two PrP27-30 glycotypes (type 1A and type 2A) are produced in sCJD. Type 1A is more frequently associated with methionine than valine in position 129. Type 1A is also formed in Val210lle fCJD. In Glu200Lys fCJD and GSS patients, we found that PrP27-30 has the same mobility of type 1 but different glycosylation ratios (type 1B). Our findings indicate that the polymorphic residue 129 of PrP has a leading role in determining the proteinase degradation site of PrPsc while mutant residues 102 or 200 influence only the glycosylation pattern.
    No preview · Article · Sep 1999 · Brain Research Bulletin
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    G Macchi · M Bentivoglio
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    ABSTRACT: The classical concept of "nonspecific" thalamus, as distinguished from the principal thalamic nuclei (i.e. the primary sensory, motor and limbic relays) is here briefly revisited in the light of anatomical investigations performed in the last decades, and primarily those based on tract tracing techniques. Altogether these data pointed out that the so-called "nonspecific" thalamus is composed by a heterogeneous collection of nuclear masses, which display not only species differences, but also marked internuclear variations in their cytological and neurochemical features, connections, areal and laminar distribution upon the cortex, and functional properties. Thus, the "nonspecific" thalamus exerts a modulatory role on cortical activity, chiefly regulated at the intrathalamic level by the interplay between the thalamic reticular nucleus and the interneurons and projection neurons of the dorsal thalamus. However, each of the components that have been traditionally considered as "nonspecific" also subserves selective roles in the transfer of different kinds of information from the thalamus to the cerebral cortex and basal ganglia.
    Preview · Article · Jun 1999 · Archives italiennes de biologie
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    ABSTRACT: Fatal familial insomnia (FFI) is an inherited prion disease linked to a mutation at codon 178 of the PRNP gene that results in aspartic acid to asparagine substitution, in coupling phase with methionine at position 129. The disease is characterized clinically by insomnia with disturbances of the autonomic, endocrine, and motor systems and neuropathologically by selective degeneration of the thalamus. Phenotypic variability is well known and has been linked to homozygosity or heterozygosity at PRNP codon 129. We report the clinical, neuropathologic, and biochemical findings and genomic analysis of a patient with FFI from a new Italian kindred. Although homozygous for methionine at codon 129, this patient showed some clinical and pathologic features most commonly found in heterozygotes.
    No preview · Article · Mar 1998 · Neurology
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    ABSTRACT: A morphometric investigation disclosed most thalamic nuclei severely degenerated in two patients with fatal familial insomnia. Associative and motor nuclei lost 90% neurons, and limbic-paralimbic, intralaminar and reticular nuclei lost 60%. These findings point to the disorganization of most thalamic circuits as a condition necessary for the sleep-wake rhythm being affected.
    No preview · Article · Nov 1997 · Brain Research
  • Giorgio Macchi · Edward G. Jones
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    ABSTRACT: The nomenclature most commonly applied to the motor-related nuclei of the human thalamus differs substantially from that applied to the thalamus of other primates, from which most knowledge of input-output connections is derived. Knowledge of these connections in the human is a prerequisite for stereotactic neurosurgical approaches designed to alleviate movement disorders by the placement of lesions in specific nuclei. Transfer to humans of connectional information derived from experimental studies in nonhuman primates requires agreement about the equivalence of nuclei in the different species, and dialogue between experimentalists and neurosurgeons would be facilitated by the use of a common nomenclature. In this review, the authors compare the different nomenclatures and review the cyto- and chemoarchitecture of the nuclei in the anterolateral aspect of the ventral nuclear mass in humans and monkeys, suggest which nuclei are equivalent, and propose a common terminology. On this basis, it is possible to identify the nuclei of the human motor thalamus that transfer information from the substantia nigra, globus pallidus, cerebellum, and proprioceptive components of the medial lemniscus to prefrontal, premotor, motor, and somatosensory areas of the cerebral cortex. It also becomes possible to suggest the principal functional systems involved in stereotactically guided thalamotomies and the functional basis of the symptoms observed following ischemic lesions in different parts of the human thalamus.
    No preview · Article · May 1997 · Journal of Neurosurgery
  • C Masullo · G Macchi
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    ABSTRACT: Creutzfeldt-Jakob disease (CJD) belongs to the group of subacute spongiform encephalopathies of animals and man. Their pathogenesis is certainly related to the formation and deposition in the brain of an amyloid-type specific protein, named PrPres (prion protein-resistant). The neuropathological topography of CJD does generally admit that archicortex is relatively spared, but only a few papers have been devoted to this issue. A neuropathological study of CJD cases divided in sporadic, familial, and iatrogenic forms of the disease has been carried out, taking into consideration the archipallial lesions in relation to different clinical and neuropathological parameters. The pyramidal cell layer of CA1 of all CJD cases did not show any major loss of neurons in comparison to that observed in other cortical fields of the limbic cortex (mainly in the presubicular and entorhinal cortex) and of the neocortex. Spongiogliotic reaction was observed only in the stratum radiatum and molecularis lacunosum in a iatrogenic case of the disease. The findings observed in the pyramidal cell layer of CA1 were neither related to the clinical duration of the disease nor to the severity of the lesions found in other limbic and neocortical areas. The results of this study support the view of no close relationships between the demential syndrome typically related to the clinical onset and progression of CJD, and the structural damage of the hippocampus classically involved in the pathogenetic mechanism of the amnestic syndrome related to the clinical presentation and course of more common forms of dementias, such as Alzheimer's disease.
    No preview · Article · Jan 1997 · Clinical neuropathology
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    ABSTRACT: We present a new, large, Italian family affected by Gerstmann-Sträussler-Scheinker syndrome (GSS) associated with the Pro to Leu point mutation at codon 102 of the prion protein gene (PRNP). The affected members of this family show a remarkable phenotypic variability of the disease: three of them had a clinical picture characterized by dementia and a brief illness duration (less than 1 year), while the other five members presented an ataxic, slowly evolving syndrome (a clinical duration of 3 to 4 years) with no evidence of cognitive impairment. Despite these remarkable clinical differences among affected members, we found no correlation between the clinical presentation and the codon 129 or codon 219 genotypes. These data suggest that factors as yet unidentified may influence the clinical expression of the disease.
    No preview · Article · Oct 1996 · Neurology
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    Full-text · Article · Aug 1996 · Journal of Neurology Neurosurgery & Psychiatry
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    ABSTRACT: The last decade has witnessed major changes in the experimental approach to the study of the thalamus and to the analysis of the anatomical and functional interrelations between thalamic nuclei and cortical areas. The present review focuses on the novel anatomical approaches to thalamo-cortical connections and thalamic functions in the historical framework of the classical studies on the thalamus. In the light of the most recent data it is here discussed that: a) the thalamus can subserve different functions according to functional changes in the cortical and subcortical afferent systems; b) the multifarious thalamic cellular entities play a crucial role in the different functional states.
    Full-text · Article · May 1996 · The Italian Journal of Neurological Sciences
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    ABSTRACT: Hadroproductions of charmonium and bottomonium χJ in polarized pp collisions at RHIC energies are studied. Two-spin asymmetries ALLχJ(pp) for these reactions allow one to determine polarized gluon distributions in a proton.
    No preview · Article · Apr 1996 · Physics Letters B
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    ABSTRACT: Neuronal cell populations giving origin to bifurcating projections to the septum and the entorhinal cortex were studied in the rat by means of double retrograde labeling using the fluorescent tracers Fast Blue and Diamidino Yellow. Double labeled pyramidal neurons were consistently detected in the temporal level of the CA1 area and subiculum of the hippocampal formation, where they represented at least 50% of the cells retrogradely labeled from the entorhinal injections. Double labeled neurons were also detected in the amygdala, where they prevailed in the basal complex. Scattered double labeled neurons were observed in a number of hypothalamic nuclei, with a slight predominance in the preoptic region. Finally, a few double labeled cells were detected in the midline thalamus, and especially in the thalamic paraventricular nucleus. In all these structures, double labeled neurons were located ispilaterally to the injection sites. The present data indicate that the septum and entorhinal cortex are tightly interconnected by axonal bifurcations deriving from a variety of telencephalic and diencephalic sources.
    Full-text · Article · Feb 1996 · Brain Research Bulletin
  • C Masullo · P W Brown · G Macchi
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    ABSTRACT: This is the first report of a definite case of Creutzfeldt-Jakob disease in an Iranian and it has been confirmed by a neuropathological study and by the immunoelectrophoretic demonstration of PrP, the pathological amyloid protein specific to the spongiform encephalopathies. The clinical course and the topography and severity of brain pathology classify this case as of panencephalopathic type and support the view of different phenotypic expressions of CJD in relation to the existence of multiple strains of the causative agent.
    No preview · Article · Jan 1996 · Clinical neuropathology
  • G Marini · R Giglio · G Macchi · M Mancia
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    ABSTRACT: The role of the nucleus reticularis thalami in spike-wave discharges in rats with genetic absence epilepsy has already been demonstrated. This study further investigated the role of the nucleus reticularis thalami in paroxysmal synchronizations in Sprague-Dawley rats; this strain shows no propensity to epileptic activity. Electroencephalographic patterns were followed in chronically implanted, unrestrained rats. After both electrolytic and chemical unilateral lesions, stereotaxically placed in the anterolateral sectors of this nucleus (verified post mortem), abnormal electroencephalographic rhythms (high-voltage polyspikes and spike-wave complexes) were recorded from the frontoparietal cortex, primarily in the contralateral hemisphere. Stereotyped discharges at 3 Hz developed progressively from multiple spikes within the alpha frequency range through the lengthening of the wave component. The excessive synchronized activity recorded from the intact hemisphere was of greater amplitude and occurred slightly earlier than from the lesioned hemisphere. These EEG patterns were associated with behavioural manifestations closely resembling those seen during absence seizures in humans. Bilateral lesions did not induce paroxysmal activity, both hemispheres being characterized by dominant delta/theta activity without signs of EEG-synchronized sleep. The seizures may thus have been due to disinhibition of the contralateral reticularis nucleus, recently shown to project to the reticularis nucleus of the other side in rats. This working hypothesis is supported by callosal cuts. The results indicate that the reticular neurons exert a control over neocortical paroxysmal activity even in animals which do not present genetic absence epilepsy.
    No preview · Article · Dec 1995 · European Journal of Neuroscience
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    ABSTRACT: Creutzfeldt-Jakob disease (CJD), a subacute spongiform encephalopathy, is generally included among the group of human and animal diseases which is transmissible by a non-conventional agent, the prion, whose expression is conditioned by the host's genome. The process leading to neuropathological changes is still unknown. We report the neuropathological findings in 2 cases of the "panencephalopathic" variant of CJD, which is relatively common in Japan, but extremely rare in Europe and North America. When compared with the classical form this variant is characterized by a relatively long clinical course with persistent vegetative state and primary involvement of the white matter presenting in the form of demyelination and gemistocytic gliosis. The selective involvement of certain thalamic nuclei is a particular pathological feature in both our cases. There was practically complete neuronal loss with diffuse gliosis of the anteroventral (AV) and dorsomedial (DM) nuclei, while the neuronal loss in the pulvinar remained moderate: the other nuclei were apparently spared. A similar involvement of the thalamus has been reported in fatal familial insomnia, a recently described prion disease in which these lesions are predominant. A comparable distribution has also been observed in other degenerative neurological diseases such as Steele-Richardson-Olszewski disease, Alzheimer disease, and thalamic dementia (selective thalamic atrophy or with multisystemic degeneration). The AV and DM nuclei, commonly referred to as "limbic thalamus" represent phylogenetically the most recent thalamic structures and would appear to play an important role in the superior functions in man as memory, attention and awareness. In our cases thalamic lesions are selective, bilateral, and symmetric, not explained by Wallerian degeneration. These lesions may be due to the primary pathogenetic properties of the infectious agent. The rapid clinical evolution in a persistent vegetative state could be consequential to precocious and severe disfunction of the limbic thalamus.
    No preview · Article · Nov 1995 · Clinical neuropathology
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    ABSTRACT: Projections from the claustrum (Cl) and the thalamic anterior intralaminar nuclei (AIN) to different representations within the primary somatosensory (S1) and visual (V1) areas were studied using the multiple retrograde fluorescent tracing technique. The injected cortical regions were identified electrophysiologically. Retrograde labeling in Cl reveals two different projection patterns. The first pattern is characterized by a clear topographic organization and is composed of two parts. The somatosensory Cl shows a dorsoventral progression of cells projecting to the hindpaw, forepaw, and face representations of S1. The visual Cl has cells projecting to the vertical meridian representation of V1 surrounded dorsally by neurons projecting to the representation of retinal periphery. A second pattern of Cl projections is composed of neurons that are distributed diffusely through the nucleus. In both somatosensory and visual sectors, these intermingle with the topographically projecting cells. Neurons retrogradely labeled from cortical injections are always present in the AIN. In the central medial nucleus, the segregation of modality is evident: The visual-projecting sector is dorsal, and the somatosensory is ventral. Projections from the central lateral nucleus display detectable somatotopic and retinotopic organization: Individual regions are preferentially connected with specific representations of S1 or V1. In the paracentral nucleus, no clear regional preferences are detectable. Also performed were comparisons of the proportions of neurons projecting to different sensory representations. Projections to V1 from both AIN and Cl are biased towards the retinal periphery representation. S1 projection preference is for the forepaw representation in Cl and for the hindpaw in the AIN. The quantitative analysis of multiply labeled cells reveals that, compared to Cl, the AIN contains a higher proportion of neurons branching between different representations of S1 or V1. The concept of topographic vs. diffuse projecting systems is reviewed and discussed, and functional implications of quantitative analysis are considered.
    No preview · Article · Nov 1995 · The Journal of Comparative Neurology

  • No preview · Article · Dec 1994 · Neurobiology of Aging
  • G Macchi · A L Abbamondi

    No preview · Article · Nov 1994 · Minerva anestesiologica
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    ABSTRACT: No abstract is available for this article.
    No preview · Article · Jul 1994 · Annals of the New York Academy of Sciences

Publication Stats

2k Citations
204.38 Total Impact Points

Institutions

  • 1978-2006
    • Catholic University of the Sacred Heart
      • • Institute of Neurology
      • • Institute of Pharmacology
      Roma, Latium, Italy
  • 1977-2001
    • Università Cattolica del Sacro Cuore
      Milano, Lombardy, Italy
  • 1999
    • University of Verona
      Verona, Veneto, Italy
  • 1997
    • University of California, Irvine
      • Department of Anatomy and Neurobiology
      Irvine, California, United States
  • 1995
    • University of Florence
      • Dipartimento di Neuroscienze, Psicologia, Area del Farmaco e Salute del Bambino
      Florens, Tuscany, Italy
  • 1975-1995
    • The Catholic University of America
      • Department of Psychology
      Washington, Washington, D.C., United States
  • 1959
    • Università degli studi di Parma
      Parma, Emilia-Romagna, Italy