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1.
Clin Neurophysiol ; 130(10): 1833-1858, 2019 10.
Article En | MEDLINE | ID: mdl-31401492

The goal of this paper is to examine existing methods to study the "Human Brain Connectome" with a specific focus on the neurophysiological ones. In recent years, a new approach has been developed to evaluate the anatomical and functional organization of the human brain: the aim of this promising multimodality effort is to identify and classify neuronal networks with a number of neurobiologically meaningful and easily computable measures to create its connectome. By defining anatomical and functional connections of brain regions on the same map through an integrated approach, comprising both modern neurophysiological and neuroimaging (i.e. flow/metabolic) brain-mapping techniques, network analysis becomes a powerful tool for exploring structural-functional connectivity mechanisms and for revealing etiological relationships that link connectivity abnormalities to neuropsychiatric disorders. Following a recent IFCN-endorsed meeting, a panel of international experts was selected to produce this current state-of-art document, which covers the available knowledge on anatomical and functional connectivity, including the most commonly used structural and functional MRI, EEG, MEG and non-invasive brain stimulation techniques and measures of local and global brain connectivity.


Brain/physiology , Electroencephalography/methods , Magnetic Resonance Imaging/methods , Magnetoencephalography/methods , Nerve Net/physiology , Transcranial Magnetic Stimulation/methods , Brain/diagnostic imaging , Connectome/methods , Humans , Nerve Net/diagnostic imaging , Neural Pathways/diagnostic imaging , Neural Pathways/physiology
2.
Neuroscience ; 290: 185-95, 2015 Apr 02.
Article En | MEDLINE | ID: mdl-25595977

Human African trypanosomiasis or sleeping sickness is a severe, neglected tropical disease caused by the extracellular parasite Trypanosoma brucei. The disease, which leads to chronic neuroinflammation, is characterized by sleep and wake disturbances, documented also in rodent models. In rats and mice infected with Trypanosoma brucei brucei, we here tested the hypothesis that the disease could target neurons of the lateral hypothalamus (LH) containing orexin (OX)-A or melanin-concentrating hormone (MCH), implicated in sleep/wake regulation. In the cerebrospinal fluid of infected rats, the OX-A level was significantly decreased early after parasite neuroinvasion, and returned to the control level at an advanced disease stage. The number of immunohistochemically characterized OX-A and MCH neurons decreased significantly in infected rats during disease progression and in infected mice at an advanced disease stage. A marked reduction of the complexity of dendritic arborizations of OX-A neurons was documented in infected mice. The evaluation of NeuN-immunoreactive neurons did not reveal significant neuronal loss in the LH of infected mice, thus suggesting a potential selective vulnerability of OX-A and MCH neurons. Immunophenotyping and quantitative analysis showed in infected mice marked activation of microglial cells surrounding OX-A neurons. Day/night oscillation of c-Fos baseline expression was used as marker of OX-A neuron activity in mice. In control animals Fos was expressed in a higher proportion of OX-A neurons in the night (activity) phase than in the day (rest) phase. Interestingly, in infected mice the diurnal spontaneous Fos oscillation was reversed, with a proportion of OX-A/Fos neurons significantly higher at daytime than at nighttime. Altogether the findings reveal a progressive decrease of OX-A and MCH neurons and dysregulation of OX-A neuron diurnal activity in rodent models of sleeping sickness. The data point to the involvement of these peptidergic neurons in the pathogenesis of sleep/wake alterations in the disease and to their vulnerability to inflammatory signaling.


Hypothalamic Hormones/metabolism , Melanins/metabolism , Neurons/physiology , Orexins/metabolism , Pituitary Hormones/metabolism , Trypanosoma brucei brucei , Trypanosomiasis, African/physiopathology , Animals , Cell Count , Circadian Rhythm/physiology , Disease Models, Animal , Disease Progression , Immunohistochemistry , Male , Mice, Inbred C57BL , Microglia/parasitology , Microglia/pathology , Microglia/physiology , Neurons/parasitology , Neurons/pathology , Proto-Oncogene Proteins c-fos/metabolism , Rats, Sprague-Dawley , Trypanosomiasis, African/pathology
3.
Neuroscience ; 252: 438-42, 2013 Nov 12.
Article En | MEDLINE | ID: mdl-24288808

This paper on Rita Levi-Montalcini (1909-2012), who received in 1986 the Nobel Prize in Physiology or Medicine for the discovery of nerve growth factor, focuses on aspects of her advocacy and her commitment to education in which she has been especially active in the last part of her long life. With passionate confidence on the capabilities of the aging brain (together with severe admonition against the pursuit of immortality), she encouraged contributions of senior citizens to the society. Always projected into the future, with enduring faith in the potential of young individuals, in education as a key to development, in the capabilities of women, in the importance of gender equality, Rita established in 2001 the Rita Levi-Montalcini Foundation for the education of African women. Her legacy on engagement for a better 'global village' should not be forgotten by the neuroscience community.


Foundations , Nerve Growth Factor/history , Neurology/history , History, 20th Century , History, 21st Century , Nobel Prize , United States
4.
Neurology ; 76(10): 895-902, 2011 Mar 08.
Article En | MEDLINE | ID: mdl-21383325

BACKGROUND: Gap junctions are specialized channels composed of several connexins, membrane proteins that mediate electrical and metabolic coupling between cells. Previous data have suggested that changes in the expression of Cx43, the main astrocytic Cx isoform, may be involved in seizure activity in human epileptic tissue. However, Cx43 has never been examined in focal cortical dysplasia (FCD) and in other human refractory epilepsies. METHODS: We analyzed Cx43 protein localization and Cx43 mRNA levels in surgical specimens of cortex from a cohort of patients with intractable epilepsy vs control nonepileptic tissue. Samples had neuropathologically defined diagnosis of cryptogenic epilepsy or epilepsy secondary to FCD. RESULTS: Cx43 immunoreactivity, which labeled punctate elements, did not reveal distinctive features in cryptogenic epilepsy and FCD type IA and IIA. A peculiar pattern of immunolabeling was instead observed in FCD type IIB, in which large aggregates of Cx43-immunopositive puncta were clustered around subsets of balloon cells and astrocytes. Further characterization revealed that these balloon cells do not express markers of precursor cells, such as CD34. Quantitative real-time reverse transcriptase PCR showed elevated levels of Cx43 transcript in a subgroup (25%) of cryptogenic epilepsy specimens compared to control and FCD ones. CONCLUSIONS: Our study points out that a rearrangement of Cx43-positive elements is part of abnormal tissue organization in FCD type IIB, and that cryptogenic epilepsies include forms with increased Cx43 mRNA expression. The data implicate functional consequences of altered Cx43 expression, and therefore of altered gap junctional coupling, in abnormal network properties of subtypes of human refractory epilepsies.


Cerebral Cortex/metabolism , Connexin 43/metabolism , Epilepsy/pathology , Adolescent , Adult , Child , Cohort Studies , Connexin 43/genetics , Female , Gene Expression/genetics , Humans , Male , Middle Aged , Nerve Tissue Proteins/metabolism , RNA, Messenger/metabolism , Young Adult
5.
Eur J Histochem ; 51 Suppl 1: 65-72, 2007.
Article En | MEDLINE | ID: mdl-17703596

Solitary chemosensory cells (SCCs), which resemble taste bud cells, are present in the epidermis and oropharynx of most primary aquatic vertebrates. Recent studies have led to the description of SCCs also in mammals too. In the airway and digestive apparatus, these elements form a diffuse chemosensory system. SCCs do not aggregate into groups and in SCCs, as in taste bud cells, immunoreactivity forthe G-protein subunit alpha-gustducin and for other molecules of the chemoreceptive cascade was found. Questions remain about the role of the diffuse chemosensory system in control of complex functions (e.g. airway surface liquid secretion) and about the involvement of chemoreceptors in respiratory diseases. Therapeutic actions targeting chemoreceptors could be tested in the treatment of respiratory diseases.


Chemoreceptor Cells/cytology , Respiratory System/cytology , Taste Buds/cytology , Animals , Humans
6.
Brain Res Bull ; 71(1-3): 127-38, 2006 Dec 11.
Article En | MEDLINE | ID: mdl-17113938

Temporal lobe epilepsy (TLE) is the most common and pharmacoresistant form of epilepsy. Problems that cause pharmacoresistance may include delayed therapy due to late consultation, especially in developing countries. Our study aimed at unraveling consequences of delayed drug treatment using a rat model of TLE. Following pilocarpine-induced status epilepticus interrupted after 4h, rats were continuously videorecorded for onset and recurrence of spontaneous convulsive seizures. The animals were then treated for 50 days with carbamazepine (CBZ; first-line drug in TLE and effective also in rats), starting at seizure onset (27.22+/-3.38 days after status epilepticus) or 50 days later, and compared with epileptic untreated rats and non-epileptic CBZ-treated ones. Convulsive seizure frequency and duration, and hippocampal cell changes were evaluated. In particular, parvalbumin-containing hippocampal interneurons, astrocytes and microglia were characterized with immunohistochemistry and quantitative analyses. Prompt administration of CBZ suppressed seizures; delayed treatment only decreased frequency of convulsive seizures, which were also relatively prolonged. In hippocampal regions, histopathological damage, parvalbumin immunoreactivity loss, and glial activation were very marked after delayed treatment, and were reduced only slightly compared to untreated epilepsy, but enhanced compared to early treatment. The data on high frequency and duration of convulsive seizures in late-therapy rats indicate that delayed CBZ administration caused a high degree of drug resistance. This condition was subserved by severe damage in the hippocampus, presumably consequent to long-term seizure recurrence. Overall the data indicate that the paradigm of delayed treatment of limbic epilepsy could provide a model of drug-refractory TLE with hippocampal sclerosis.


Anticonvulsants/administration & dosage , Brain Damage, Chronic/etiology , Drug Resistance/physiology , Epilepsy, Temporal Lobe/complications , Epilepsy, Temporal Lobe/drug therapy , Hippocampus/physiopathology , Animals , Brain Damage, Chronic/physiopathology , Brain Damage, Chronic/prevention & control , Carbamazepine/pharmacology , Convulsants/pharmacology , Disease Models, Animal , Down-Regulation/drug effects , Down-Regulation/physiology , Drug Administration Schedule , Drug Resistance/drug effects , Epilepsy/complications , Epilepsy/drug therapy , Epilepsy/physiopathology , Epilepsy, Temporal Lobe/physiopathology , Gliosis/etiology , Gliosis/physiopathology , Gliosis/prevention & control , Hippocampus/drug effects , Hippocampus/pathology , Male , Nerve Degeneration/etiology , Nerve Degeneration/physiopathology , Nerve Degeneration/prevention & control , Neurons/drug effects , Neurons/metabolism , Neurons/pathology , Parvalbumins/metabolism , Pilocarpine/pharmacology , Rats , Status Epilepticus/complications , Status Epilepticus/drug therapy , Status Epilepticus/physiopathology , Time Factors
7.
Neuroscience ; 141(2): 645-661, 2006 Aug 25.
Article En | MEDLINE | ID: mdl-16730918

Numerous neurological diseases which include neuroinflammatory components exhibit an age-related prevalence. The aging process is characterized by an increase of inflammatory mediators both systemically and in the brain, which may prime glial cells. However, little information is available on age-related changes in the glial response of the healthy aging brain to an inflammatory challenge. This problem was here examined using a mixture of the proinflammatory cytokines interferon-gamma and tumor necrosis factor-alpha, which was injected intracerebroventricularly in young (2-3.5 months), middle-aged (10-11 months) and aged (18-21 months) mice. Vehicle (phosphate-buffered saline) was used as control. After a survival of 1 or 2 days (all age groups) or 4 days (young and middle-aged animals), immunohistochemically labeled astrocytes and microglia were investigated both qualitatively and quantitatively. In all age groups, astrocytes were markedly activated in periventricular as well as in deeper brain regions 2 days following cytokine treatment, whereas microglia activation was already evident at 24 h. Interestingly, cytokine-induced activation of both astrocytes and microglia was significantly more marked in the brain of aged animals, in which it included numerous ameboid microglia, than of younger age groups. Moderate astrocytic activation was also seen in the hippocampal CA1 field of vehicle-treated aged mice. FluoroJade B histochemistry and the terminal deoxynucleotidyl transferase-mediated UTP nick-end labeling technique, performed at 2 days after cytokine administration, did not reveal ongoing cell death phenomena in young or aged animals. This indicated that glial cell changes were not secondary to neuronal death. Altogether, the findings demonstrate for the first time enhanced activation of glial cells in the old brain, compared with young and middle-aged subjects, in response to cytokine exposure. Interestingly, the results also suggest that such enhancement does not develop gradually since youth, but appears characterized by relatively late onset.


Aging/physiology , Brain/cytology , Brain/drug effects , Cytokines/pharmacology , Neuroglia/drug effects , Age Factors , Analysis of Variance , Animals , Antigens, Differentiation/metabolism , CD11b Antigen/metabolism , Cell Death/drug effects , Fluoresceins , Glial Fibrillary Acidic Protein/metabolism , Immunohistochemistry/methods , In Situ Hybridization/methods , In Situ Nick-End Labeling/methods , Male , Mice , Mice, Inbred C57BL , Organic Chemicals , Time Factors
9.
Neuroimage ; 18(2): 375-89, 2003 Feb.
Article En | MEDLINE | ID: mdl-12595191

The rat brain was investigated with structural and functional magnetic resonance imaging (MRI) 12 h after the arrest of pilocarpine-induced status epilepticus lasting 4 h. Histopathological data, obtained immediately after MRI analysis, were correlated with the images through careful evaluation of tissue shrinkage. Diffusion-weighted and T2-weighted imaging showed changes throughout the cerebral cortex, hippocampus, amygdala, and medial thalamus. However, only T2-weighted imaging, based on rapid acquisition relaxation-enhanced sequences, revealed in the cortex inhomogeneous hyperintensity that was highest in a band corresponding to layer V. Regional cerebral blood volume (rCBV) maps were generated using T2*-weighted gradient-echo images and an ultrasmall superparamagnetic iron oxide contrast agent. In the cortex, rCBV peaked in superficial and deep bands exhibiting a distribution complementary to the highest T2-weighted intensity. Selective rCBV increase was also documented in the hippocampus and subcortical structures. In tissue sections, alterations indicative of marked edema were found with Nissl staining in areas corresponding to the highest T2-weighted intensity. Degenerating neurons, revealed by FluoroJadeB histochemistry, were instead concentrated in tissue exhibiting hyperperfusion in rCBV maps, such as hippocampal subfields and dentate gyrus, cortical layers II/III and VI, and medial thalamus. The data indicate that:(i) T2-weighted imaging provides a sensitive tool to investigate edematous brain alterations that follow sustained seizures; (ii) rCBV maps reveal regional hyperperfusion; (iii) rCBV peaks in tissue exhibiting marked neurodegeneration, which may not be selectively revealed by structural MRI. The findings provide an interpretation of the brain response to sustained seizures revealed in vivo by different strategies of MRI analysis.


Brain/physiopathology , Image Enhancement , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Status Epilepticus/physiopathology , Amygdala/drug effects , Amygdala/pathology , Amygdala/physiopathology , Animals , Brain/drug effects , Brain/pathology , Brain Mapping , Cerebral Cortex/drug effects , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Gyrus Cinguli/drug effects , Gyrus Cinguli/pathology , Gyrus Cinguli/physiopathology , Hippocampus/drug effects , Hippocampus/pathology , Hippocampus/physiopathology , Male , Midline Thalamic Nuclei/drug effects , Midline Thalamic Nuclei/pathology , Midline Thalamic Nuclei/physiopathology , Neural Pathways/drug effects , Neural Pathways/pathology , Neural Pathways/physiopathology , Pilocarpine , Rats , Rats, Wistar , Regional Blood Flow/physiology , Status Epilepticus/chemically induced , Status Epilepticus/pathology
10.
Neuroscience ; 115(2): 331-5, 2002.
Article En | MEDLINE | ID: mdl-12421599

In transgenic mice carrying the G93A human mutation of Cu/Zn superoxide dismutase (SOD1), which provide a model of familial amyotrophic lateral sclerosis, we investigated, before the onset of symptoms, two parameters of the response of facial motoneurons to nerve transection, i.e. nitric oxide synthase induction and motoneuron loss. Axotomy elicited after 2 and 3 weeks high nitric oxide synthase expression in facial motoneurons of wild-type mice, whereas the induction was very weak or absent in transgenic mice. At 1 month post-axotomy, loss of facial motoneurons was significantly higher in mutant mice than in wild-type littermates. Thus, SOD1 mutation interferes with the oxidative cascade elicited by axonal injury in cranial motoneurons. The results also indicate that the adverse gain of function of the mutant SOD1 enhances the vulnerability of motoneurons to peripheral stressful conditions.


Amyotrophic Lateral Sclerosis/pathology , Facial Nerve/pathology , Motor Neurons/pathology , Superoxide Dismutase/genetics , Animals , Axotomy , Cell Count , Disease Models, Animal , Humans , Mice , Mice, Transgenic , Motor Neurons/enzymology , NADPH Dehydrogenase/analysis , Nitric Oxide Synthase/analysis , Superoxide Dismutase-1
11.
Exp Neurol ; 176(1): 133-42, 2002 Jul.
Article En | MEDLINE | ID: mdl-12093090

To ascertain whether signaling due to peripheral inflammation affects motoneuron vulnerability, we examined in adult rats the reaction to axonal injury of facial motoneurons primed by muscle inflammation. In this double-hit paradigm, preconditioning was achieved by injections into the facial muscles of the T cell mitogen phytohemagglutinin, which was found in a previous study ( 11 ) to elicit a retrograde response in motoneurons. Facial nerve transection was used as test lesion. Intramuscular injections of saline prior to axotomy were used as control for lectin pretreatment. In rats pretreated with phytohemagglutinin injection, upregulation of the expression of the antiapoptotic bcl-2 gene, examined with in situ hybridization, was significantly higher in facial motoneurons at 2 days postaxotomy compared with saline-injected control cases. After repeated phytohemagglutinin injections followed by nerve transection, induction in facial motoneurons of nitric oxide synthase, revealed by histochemistry and immunohistochemistry, as well as activation of the surrounding microglia, was enhanced at 14 days postaxotomy with respect to the saline-treated control cases. At the same time point, no significant intergroup difference was detected in the intensity of astrocytic activation. At 1 month postaxotomy, stereological cell counts revealed that motoneuron loss was significantly greater in the cases pretreated with phytohemagglutinin than in the saline-treated cases. The data point out that the response of the facial motor nucleus to axonal damage is altered by previous exposure to peripheral inflammation and that such preconditioning stimulus enhances motoneuron vulnerability to nerve injury.


Antigens, CD , Antigens, Neoplasm , Antigens, Surface , Avian Proteins , Blood Proteins , Brain Stem/physiopathology , Facial Muscles/innervation , Inflammation/physiopathology , Motor Neurons , Animals , Axotomy , Basigin , Brain Stem/pathology , Cell Count , Facial Muscles/immunology , Glial Fibrillary Acidic Protein/biosynthesis , Immunohistochemistry , In Situ Hybridization , Inflammation/chemically induced , Inflammation/pathology , Male , Membrane Glycoproteins/biosynthesis , Mitogens , Motor Neurons/pathology , Motor Neurons/physiology , NADPH Dehydrogenase/metabolism , Neuroglia/metabolism , Neuroglia/pathology , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type I , Phytohemagglutinins , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Messenger/metabolism , Rats , Rats, Wistar , T-Lymphocytes/immunology
13.
Ital J Anat Embryol ; 106(2 Suppl 1): 467-73, 2001.
Article En | MEDLINE | ID: mdl-11729991

Brain mast cells are selectively concentrated in the thalamus of many mammalian species. We here describe by light and electron microscopy in the normal thalamus of adult rats the features of mast cell degranulation, which indicate an active release of the mediators stored in their intracellular granules. The state of activity of thalamic mast cells in basal conditions was found to range from the release of a few granules to a massive degranulation, and the latter process was much less frequent than a partial degranulation. Mast cells were subdivided in three categories (fully granulated, partially or massively degranulated) on the basis of their cytoplasmic features revealed by acidic toluidine blue staining; the fully granulated cells were found to represent only 23 % of thalamic mast cells. This strategy of evaluation could be of help in the comparison of the functional correlates of mast cells in different conditions and experimental paradigms. However, we also demonstrated with image analysis a continuum of the variation of staining intensity of granulated and degranulating mast cells, without a sharp subdivision into different categories. Therefore our results reveal that the vast majority of mast cells are active in the thalamus in basal conditions, and that image analysis can provide an objective index of the activity of these cells.


Mast Cells/ultrastructure , Secretory Vesicles/ultrastructure , Thalamus/ultrastructure , Animals , Blood Vessels/ultrastructure , Male , Mast Cells/immunology , Mast Cells/metabolism , Microscopy, Electron , Rats , Rats, Wistar , Secretory Vesicles/immunology , Secretory Vesicles/metabolism , Thalamus/immunology , Thalamus/metabolism
14.
Neuroscience ; 104(4): 979-1002, 2001.
Article En | MEDLINE | ID: mdl-11457585

At variance with pilocarpine-induced epilepsy in the laboratory rat, pilocarpine administration to the tropical rodent Proechimys guyannensis (casiragua) elicited an acute seizure that did not develop in long-lasting status epilepticus and was not followed by spontaneous seizures up to 30 days, when the hippocampus was investigated in treated and control animals. Nissl staining revealed in Proechimys a highly developed hippocampus, with thick hippocampal commissures and continuity of the rostral dentate gyri at the midline. Immunohistochemistry was used to study calbindin, parvalbumin, calretinin, GABA, glutamic acid decarboxylase, and nitric oxide synthase expression. The latter was also investigated with NADPH-diaphorase histochemistry. Cell counts and densitometric evaluation with image analysis were performed. Differences, such as low calbindin immunoreactivity confined to some pyramidal cells, were found in the normal Proechimys hippocampus compared to the laboratory rat. In pilocarpine-treated casiraguas, stereological cell counts in Nissl-stained sections did not reveal significant neuronal loss in hippocampal subfields, where the examined markers exhibited instead striking changes. Calbindin was induced in pyramidal and granule cells and interneuron subsets. The number of parvalbumin- or nitric oxide synthase-containing interneurons and their staining intensity were significantly increased. Glutamic acid decarboxylase(67)-immunoreactive interneurons increased markedly in the hilus and decreased in the CA1 pyramidal layer. The number and staining intensity of calretinin-immunoreactive pyramidal cells and interneurons were significantly reduced. These findings provide the first description of the Proechimys hippocampus and reveal marked long-term variations in protein expression after an epileptic insult, which could reflect adaptive changes in functional hippocampal circuits implicated in resistance to limbic epilepsy.


Epilepsy/metabolism , Hippocampus/metabolism , Nerve Degeneration/metabolism , Nerve Tissue Proteins/drug effects , Neurons/metabolism , Rodentia/metabolism , Up-Regulation/drug effects , Animals , Calbindin 2 , Calbindins , Cell Count , Disease Models, Animal , Epilepsy/chemically induced , Epilepsy/pathology , Glutamate Decarboxylase/metabolism , Hippocampus/drug effects , Hippocampus/pathology , Immunohistochemistry , Male , Muscarinic Agonists/pharmacology , NADPH Dehydrogenase/metabolism , Nerve Degeneration/chemically induced , Nerve Degeneration/pathology , Nerve Tissue Proteins/biosynthesis , Neurons/drug effects , Neurons/pathology , Nitric Oxide Synthase/metabolism , Parvalbumins/metabolism , Pilocarpine/pharmacology , Rats , Rats, Wistar/anatomy & histology , Rats, Wistar/metabolism , Rodentia/anatomy & histology , S100 Calcium Binding Protein G/metabolism , Up-Regulation/physiology
15.
Brain Res Bull ; 54(5): 461-83, 2001 Mar 15.
Article En | MEDLINE | ID: mdl-11397537

We have provided a translation of Golgi's original paper on the mammalian hippocampus (first published in 1883 and reprinted numerous times), along with a preface on its historical context. Golgi believed that this part of the cerebral hemisphere showed best the exact relationship between nerve cells and nerve fibers, the most important problem in 19th century neuroscience.


Hippocampus/cytology , Neurons/cytology , Animals , History, 19th Century , Humans , Neurosciences/history , Silver Staining/history , Translations
16.
Eur J Neurosci ; 13(7): 1329-38, 2001 Apr.
Article En | MEDLINE | ID: mdl-11298793

To investigate whether motoneurons react to signals deriving from target inflammation, we studied the facial motor nucleus after injections of phytohaemagglutinin in the snout of adult rats. This plant lectin is a tool widely used to induce proliferation and activation of T lymphocytes, and we observed marked lymphocyte infiltration in the injected facial muscles. Retrograde labelling of motoneurons was not detected after peripheral injections of fluorochrome-conjugated phytohaemagglutinin. Nitric oxide synthase, revealed by NADPH-diaphorase histochemistry, OX-42-immunoreactive microglia, and expression of the cell death repressor gene bcl-2, investigated with nonradioactive in situ hybridization and immunohistochemistry, were evaluated in the facial nucleus. Daily phytohaemagglutinin injections for 4 days, mimicking repeated muscle exposure to inflammatory stimuli, resulted after 2-day survival in NADPH-diaphorase induction in motoneurons and marked activation of the surrounding microglia. Quantitative image analysis of NADPH-diaphorase staining, and OX-42 immunoreactivity and microglial cell counts indicated highly significant increases with respect to saline-injected control cases. The occurrence of a neuroprotective retrograde response was evaluated monitoring bcl-2 expression. Following single phytohaemagglutinin administration, bcl-2 mRNA was significantly upregulated at 6 h in facial motoneurons and returned to basal levels at 24 h. Bcl-2 immunoreactivity was markedly upregulated at 24 h and was still significantly higher than in controls at 7 days, when concomitant NADPH-diaphorase induction in motoneurons and microglia activation was also observed. No degenerative features were observed in motoneurons after phytohaemagglutinin injections at the examined time-points. The data point out that local muscle inflammation retrogradely elicits gene activation in motoneurons and their microenvironment.


Antigens, CD , Antigens, Neoplasm , Antigens, Surface , Avian Proteins , Blood Proteins , Facial Nerve/immunology , Motor Neurons/enzymology , Muscle, Skeletal/immunology , Muscle, Skeletal/innervation , Myositis/physiopathology , Animals , Basigin , Facial Nerve/cytology , Gene Expression/immunology , Lymphocytes/immunology , Male , Membrane Glycoproteins/analysis , Microglia/chemistry , Microglia/physiology , Motor Neurons/chemistry , Myositis/chemically induced , Myositis/immunology , NADPH Dehydrogenase/analysis , Nitric Oxide Synthase/metabolism , Phytohemagglutinins , Proto-Oncogene Proteins c-bcl-2/analysis , Proto-Oncogene Proteins c-bcl-2/genetics , RNA, Messenger/analysis , Rats , Rats, Wistar
17.
Brain Res Bull ; 54(4): 353-61, 2001 Mar 01.
Article En | MEDLINE | ID: mdl-11306186

Volkensin, a highly toxic protein retrogradely transported through axons, was used to target primary neuronal death in brainstem precerebellar relays after injection in the cerebellar cortex of rats. The reaction of astrocytes and microglia was studied with immunohistochemistry in the inferior olivary and pontine nuclei from 6 h to 14 days. Neurodegenerative features were evident since the first hours, especially in the pontine nuclei, and neuronal loss reached a plateau at 7 days in the inferior olive and at 10 days in the pons. Astrocytic activation, revealed by glial fibrillary acidic protein immunoreactivity, was concomitant with early signs of neuronal death and gradually increased. Microglia activation, revealed by OX-42 immunoreactivity, was evident at 2 days and became rapidly intense in precerebellar relays. At 1 week, marked ED-1 immunoreactivity also revealed phagocytic features of microglia, which persisted during the second week. In addition, major histocompatibility complex antigens (MHC) class I and II were induced in cells exhibiting microglial features. In the inferior olive, MHC I immunoreactivity was evident since 4 days and persisted at 14 days, whereas MHC II induction was intense at 7 days and subsided at 2 weeks. In the pontine nuclei high expression of both MHC antigens persisted instead at 14 days, probably reflecting the progression of neuronal death. Thus, targeted lethal injury of central neurons elicited prompt activation of both astrocytes and microglia; the marked microglia activation resulted in phagocytic features and immunophenotypic changes, with a temporal regulation that paralleled the evolution of neurodegenerative phenomena.


Antigens, CD , Antigens, Neoplasm , Antigens, Surface , Astrocytes/metabolism , Avian Proteins , Blood Proteins , Glial Fibrillary Acidic Protein/metabolism , Glycoproteins , Microglia/metabolism , N-Glycosyl Hydrolases , Olivary Nucleus/metabolism , Plant Lectins , Pons/metabolism , Animals , Astrocytes/drug effects , Basigin , Cell Death/physiology , H-2 Antigens/metabolism , Histocompatibility Antigens Class II/metabolism , Male , Membrane Glycoproteins/metabolism , Microglia/drug effects , Neurotoxins/administration & dosage , Neurotoxins/toxicity , Olivary Nucleus/drug effects , Plant Proteins/administration & dosage , Plant Proteins/toxicity , Pons/drug effects , Rats , Rats, Sprague-Dawley , Ribosome Inactivating Proteins, Type 2 , Ricin/administration & dosage , Ricin/toxicity
18.
Neuroscience ; 101(2): 451-8, 2000.
Article En | MEDLINE | ID: mdl-11074167

In lizards, tail loss transects spinal nerves and the cut axons elongate in the regrowing tail, providing a natural paradigm of robust regenerative response of injured spinal motoneurons. We previously ascertained that these events involve nitric oxide synthase induction in the axotomized motoneurons, suggesting a correlation of this enzyme with regeneration-associated gene expression. Here we investigated, in lizards, whether the cell death repressor Bcl-2 protein and growth-associated protein-43 (GAP-43) were also induced in motoneurons that innervate the regenerated tail in the first month post-caudotomy. Single and multiple immunocytochemical techniques, and quantitative image analysis, were performed. Nitric oxide synthase, GAP-43 or Bcl-2 immunoreactivity was very low or absent in spinal motoneurons of control lizards with intact tail. Nitric oxide synthase and GAP-43 were induced during the first month post-caudotomy in more than 75% of motoneurons which innnervate the regenerate. Bcl-2 was induced in approximately 95% of these motoneurons at five and 15days, and in about 35% at one month. The intensity of Bcl-2 and GAP-43 immunostaining peaked at five days, and nitric oxide synthase at 15days; immunoreactivity to these proteins was still significantly high at one month. Immunofluorescence revealed co-localization of nitric oxide synthase, GAP-43 and Bcl-2 in the vast majority of motoneurons at five and 15days post-caudotomy. These findings demonstrate that co-induction of nitric oxide synthase, Bcl-2 and GAP-43 may be part of the molecular repertoire of injured motoneurons committed to survival and axon regeneration, and strongly favor a role of nitric oxide synthase in motoneuron plasticity.


GAP-43 Protein/metabolism , Lizards/metabolism , Motor Neurons/metabolism , Nerve Regeneration/physiology , Nitric Oxide Synthase/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Spinal Cord/metabolism , Spinal Nerves/injuries , Tail/injuries , Animals , Axotomy/adverse effects , Cell Survival/physiology , Lizards/anatomy & histology , Motor Neurons/cytology , Neuronal Plasticity/physiology , Recovery of Function/physiology , Spinal Cord/cytology , Spinal Nerves/cytology , Spinal Nerves/metabolism , Tail/innervation , Time Factors
19.
Brain Res ; 878(1-2): 105-18, 2000 Sep 29.
Article En | MEDLINE | ID: mdl-10996141

Expression of inducible nitric oxide synthase (iNOS) protein was studied in the brain after intracerebroventricular injections of interferon (IFN)-gamma, and IFN-gamma combined with lipopolysaccharide (LPS) or tumor necrosis factor (TNF)-alpha, compared to ovalbumin as control. Wild-type mice and mice with targeted deletion of the IFN-gamma receptor gene were used. Findings based on iNOS immunoreactivity were evaluated at 1, 2, 4 and 7 days post-injection, using also quantitative image analysis and double labeling with glial cell markers. IFN-gamma administration induced iNOS immmunostaining in activated microglia and macrophages in the parenchyma surrounding the ventricular system, several cortical fields and fiber tracts. IFN-gamma-elicited iNOS immunoreactivity was down-regulated after 1 day. The number of iNOS-immunopositive cells was significantly enhanced by co-administration of LPS or TNF-alpha; IFN-gamma+TNF-alpha injections also resulted in longer persistence of iNOS immunoreactivity. No immunopositive cells were seen in the brain of IFN-gamma receptor knockout mice after IFN-gamma administration; very few immunostained macrophages were detected in these cases, mostly around the injection needle track, after co-administration of LPS or TNF-alpha. Western blot analysis confirmed a marked iNOS induction in the brain of wild-type mice 24 h after IFN-gamma+LPS injections. The findings show that inflammatory mediators circulating in the cerebrospinal fluid induce in vivo iNOS in the brain with topographical selectivity and temporal regulation. The data also demonstrate that the signaling cascade activated by IFN-gamma binding to its receptor is critical for iNOS induction, and the synergistic action of LPS and TNF-alpha as iNOS inducers in brain cells is largely mediated by the receptor-regulated action of IFN-gamma.


Brain/enzymology , Inflammation Mediators/pharmacology , Interferon-gamma/pharmacology , Lipopolysaccharides/pharmacology , Nitric Oxide Synthase/metabolism , Tumor Necrosis Factor-alpha/pharmacology , Animals , Blotting, Western , Brain/cytology , Immunohistochemistry , Inflammation Mediators/administration & dosage , Inflammation Mediators/cerebrospinal fluid , Injections, Intraventricular , Interferon-gamma/administration & dosage , Interferon-gamma/cerebrospinal fluid , Lipopolysaccharides/administration & dosage , Lipopolysaccharides/cerebrospinal fluid , Mice , Mice, Inbred C57BL/genetics , Mice, Knockout/genetics , Nitric Oxide Synthase Type II , Receptors, Interferon/deficiency , Receptors, Interferon/genetics , Reference Values , Time Factors , Tissue Distribution , Tumor Necrosis Factor-alpha/administration & dosage , Tumor Necrosis Factor-alpha/cerebrospinal fluid , Interferon gamma Receptor
20.
Int J Cardiol ; 74(2-3): 177-83, 2000 Jul 31.
Article En | MEDLINE | ID: mdl-10962119

BACKGROUND: The prognostic impact of left ventricular (LV) geometry on cardiovascular risk for patients with a first, uncomplicated acute myocardial infarction (AMI), and echocardiographic ejection fraction > or =50% has not been well described. METHODS AND RESULTS: Accordingly, 111 AMI consecutive patients (mean age 59.3+/-10 years) performed echocardiographic examination at predischarge. LV mass was calculated by means of Devereux's formula and subsequently indexed by body surface area. Fifty-three patients had LV hypertrophy and 58 patients had normal LV mass. The two groups were homogeneous for demographic, clinical and angiographic variables as well as for the incidence of residual ischemia on predischarge stress testing. During follow-up period there were 24 cardiac events (cardiac death, unstable angina and non-fatal reinfarction) in the 53 patients with LV hypertrophy and only four events in the remaining 58 patients without LV hypertrophy (RR=2.45; CI=1.76-3.41; P<0.0001). The patients with concentric LV hypertrophy showed a higher incidence of events (64%) than patients with eccentric LV hypertrophy (32%, P<0. 05) and patients with normal geometry and mass (6%, P<0.0001). Multivariate Cox regression model identified concentric geometry as the most powerful predictor of combined end-points (chi(2)=32.7, P<0. 0001). CONCLUSIONS: An increased LV mass and concentric geometry resulted important independent markers of an adverse outcome in patients with a first, uncomplicated myocardial infarction and good LV function.


Echocardiography, Doppler , Hypertrophy, Left Ventricular/diagnostic imaging , Hypertrophy, Left Ventricular/etiology , Myocardial Infarction/complications , Aged , Analysis of Variance , Cardiac Catheterization , Exercise Test , Female , Follow-Up Studies , Humans , Male , Middle Aged , Myocardial Infarction/diagnosis , Myocardial Infarction/therapy , Probability , Prognosis , Proportional Hazards Models , Sensitivity and Specificity , Statistics, Nonparametric , Stroke Volume
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