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1.
PLoS One ; 16(9): e0256461, 2021.
Article En | MEDLINE | ID: mdl-34469431

OBJECTIVE: To assess the overall effectiveness of anti-vascular endothelial growth factor (VEGF) therapy in treatment-naïve patients with neovascular age-related macular degeneration (nAMD) in a clinical practice setting. STUDY DESIGN: EAGLE was a retrospective, 2-year, cohort observational, multicenter study conducted in Italy that analyzed secondary data of treatment-naïve patients with nAMD. The primary endpoint evaluated the mean annualized number of anti-VEGF injections at Years 1 and 2. The main secondary endpoints analyzed the mean change in visual acuity (VA) from baseline and variables associated with visual outcomes at Years 1 and 2. RESULTS: Of the 752 patients enrolled, 745 (99.07%) received the first dose of anti-VEGF in 2016. Overall, 429 (57.05%) and 335 (44.5%) patients completed the 1- and 2-year follow-ups, respectively. At baseline, mean (standard deviation, SD) age was 75.6 (8.8) years and the mean (SD) VA was 53.43 (22.8) letters. The mean (SD) number of injections performed over the 2 years was 8.2 (4.1) resulting in a mean (SD) change in VA of 2.45 (19.36) (P = 0.0005) letters at Year 1 and -1.34 (20.85) (P = 0.3984) letters at Year 2. Linear regression models showed that age, baseline VA, number of injections, and early fluid resolution were the variables independently associated with visual outcomes at Years 1 and 2. CONCLUSIONS: The EAGLE study analyzed the routine clinical practice management of patients with nAMD in Italy. The study suggested that visual outcomes in clinical practice may be improved with earlier diagnosis, higher number of injections, and accurate fluid resolution targeting during treatment induction.


Angiogenesis Inhibitors/administration & dosage , Macular Degeneration/drug therapy , Retinal Neovascularization/drug therapy , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Visual Acuity/drug effects , Aged , Aged, 80 and over , Drug Administration Schedule , Female , Follow-Up Studies , Humans , Intravitreal Injections , Italy , Macular Degeneration/diagnosis , Male , Retinal Neovascularization/diagnosis , Retrospective Studies , Time Factors , Treatment Outcome
2.
Br J Ophthalmol ; 104(1): 64-73, 2020 01.
Article En | MEDLINE | ID: mdl-31079057

BACKGROUND: To evaluate the safety and tolerability of ranibizumab 0.5 mg in patients with uni/bilateral neovascular age-related macular degeneration (nAMD) and best-corrected visual acuity (BCVA)<2/10 and/or second eye affected, regardless of BCVA. METHODS: In this 12-month, prospective, multicentre, open-label, single arm, pragmatic interventional study, patients (N=941) aged ≥ 50 years were to receive ranibizumab as per approved label, monthly until maximum stable visual acuity (VA) was achieved (initially, three or more injections may be required). Thereafter, patients were to be monitored monthly for VA and treatment was to be resumed if VA was reduced due to disease activity. RESULTS: Of the 936 patients treated with ranibizumab at least once during the study, 823/113 were unilaterally/bilaterally (not simultaneously) treated . The mean (SD) number of ranibizumab injections during the study was 5.4 (2.9)/10.6 (5.0) injections in uni/bilaterally treated patients. Three systemic drug-related adverse events (AEs) (all serious, all in unilaterally treated patients) and 18 systemic AE of special interest (AESIs) (11 serious, 16/2 in unilaterally/bilaterally treated patients) occurred during the study. The annual incidence rate (AIR) (events/1000 person-years) for systemic drug-related AEs, considering a 15-day/30-day risk period, 11.0/8.5 for unilaterally treated patients. Considering the same risk period, the AIR (events/1000 person-years) for systemic AESIs for unilaterally treated patients was 22.1/19.9. Considering a 30-day risk period, the AIR (events/1000 treated eye-years) of ocular drug-related AEs was 23 and AESIs was 11.5. CONCLUSIONS: The low incidence of AEs and AESIs demonstrated the good safety and tolerability of ranibizumab in unilaterally/bilaterally treated patients with nAMD in this real-world setting.


Angiogenesis Inhibitors/adverse effects , Ranibizumab/adverse effects , Wet Macular Degeneration/drug therapy , Aged , Aged, 80 and over , Angiogenesis Inhibitors/administration & dosage , Angiogenesis Inhibitors/therapeutic use , Choroidal Neovascularization/drug therapy , Choroidal Neovascularization/epidemiology , Choroidal Neovascularization/physiopathology , Drug Administration Schedule , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/etiology , Female , Humans , Incidence , Intravitreal Injections , Italy/epidemiology , Male , Middle Aged , Prospective Studies , Ranibizumab/administration & dosage , Ranibizumab/therapeutic use , Risk Assessment/methods , Tomography, Optical Coherence , Visual Acuity/drug effects , Wet Macular Degeneration/epidemiology , Wet Macular Degeneration/physiopathology
3.
Graefes Arch Clin Exp Ophthalmol ; 257(4): 759-768, 2019 Apr.
Article En | MEDLINE | ID: mdl-30680452

PURPOSE: To evaluate criteria driving retreatment with ranibizumab in Italian patients with myopic choroidal neovascularization (mCNV). METHODS: OLIMPIC was a 12-month, phase IIIb, open-label study. Patients with active mCNV were treated with ranibizumab 0.5 mg according to the European label. The study assessed local criteria in Italy driving retreatment decisions with ranibizumab; and the efficacy, safety, and tolerability of ranibizumab. RESULTS: The mean (standard deviation [SD]) age of treated patients (N = 200) was 61.8 (12.7) years; range 22-85 years. The multivariate regression model indicated that presence of active leakage (odds ratio [OR] 95% confidence interval [CI]: 11.30 [1.03-124.14]), presence of intraretinal fluid (OR [95%CI]: 28.21 [1.55-513.73]), and an improvement in best-corrected visual acuity (BCVA) from baseline < 10 letters (OR [95%CI]: 17.60 [1.39-222.75]) were the factors with the greatest effect on retreatment with ranibizumab. The mean (SD) BCVA gain from baseline to month 12 was 8.4 (12.8) letters (P < 0.0001). The mean (SD) number of injections was 2.41 (1.53); range 1-9. Ocular and non-ocular adverse events were reported in 41 (20.5%) and 30 (15.0%) patients, respectively. CONCLUSIONS: Individualized treatment with ranibizumab was effective in improving BCVA in patients with mCNV over 12 months. Both anatomical and functional variables had significant effects on causing retreatment. There were no new safety findings. TRIAL REGISTRATION: www.ClinicalTrials.Gov (NCT No: NCT02034006).


Angiogenesis Inhibitors/therapeutic use , Choroidal Neovascularization/drug therapy , Myopia, Degenerative/drug therapy , Ranibizumab/therapeutic use , Vision Disorders/drug therapy , Adult , Aged , Aged, 80 and over , Choroidal Neovascularization/complications , Choroidal Neovascularization/physiopathology , Female , Humans , Intravitreal Injections , Male , Middle Aged , Myopia, Degenerative/etiology , Myopia, Degenerative/physiopathology , Prospective Studies , Retreatment , Subretinal Fluid , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Vision Disorders/etiology , Vision Disorders/physiopathology , Visual Acuity/physiology , Young Adult
4.
Neurobiol Dis ; 26(2): 481-95, 2007 May.
Article En | MEDLINE | ID: mdl-17398107

One of the most common causes of neurological disabilities are malformations of cortical development (MCD). A useful animal model of MCD consists of prenatal exposure to methylazoxymethanol (MAM), resulting in a postnatal phenotype characterized by cytological aberrations reminiscent of human MCD. Although postnatal effects of MAM are likely a consequence of prenatal events, little is known on how the developing brain reacts to MAM. General assumption is the effects of prenatally administered MAM are short lived (24 h) and neuroblast-specific. MAM persisted for several days after exposure in utero in both maternal serum and fetal brain, but at levels lower than predicted by a neurotoxic action. MAM levels and time course were consistent with a different mechanism of indirect neuronal toxicity. The most prominent acute effects of MAM were cortical swelling associated with mild cortical disorganization and neurodegeneration occurring in absence of massive neuronal cell death. Delayed or aborted vasculogenesis was demonstrated by MAM's ability to hinder vessel formation. In vitro, MAM reduced synthesis and release of VEGF by endothelial cells. Decreased expression of VEGF, AQP1, and lectin-B was consistent with a vascular target in prenatal brain. The effects of MAM on cerebral blood vessels persisted postnatally, as indicated by capillary hypodensity in heterotopic areas of adult rat brain. In conclusion, these results show that MAM does not act only as a neurotoxin per se, but may additionally cause a short-lived toxic effect secondary to cerebrovascular dysfunction, possibly due to a direct anti-angiogenic effect of MAM itself.


Abnormalities, Drug-Induced/physiopathology , Brain/abnormalities , Cerebral Arteries/abnormalities , Methylazoxymethanol Acetate/analogs & derivatives , Nervous System Malformations/chemically induced , Prenatal Exposure Delayed Effects/physiopathology , Animals , Aquaporin 1/metabolism , Brain/blood supply , Brain/physiopathology , Cerebral Arteries/drug effects , Cerebral Arteries/physiopathology , Cerebral Cortex/abnormalities , Cerebral Cortex/drug effects , Cerebral Cortex/physiopathology , Disease Models, Animal , Female , Methylazoxymethanol Acetate/toxicity , Neovascularization, Physiologic/drug effects , Nervous System Malformations/pathology , Nervous System Malformations/physiopathology , Neurotoxins/toxicity , Pokeweed Mitogens/metabolism , Pregnancy , Prenatal Exposure Delayed Effects/pathology , Rats , Rats, Sprague-Dawley , Teratogens/toxicity , Vascular Endothelial Growth Factor A/metabolism
5.
Proc Natl Acad Sci U S A ; 104(6): 1959-64, 2007 Feb 06.
Article En | MEDLINE | ID: mdl-17261814

Spinal muscular atrophy (SMA) is an autosomal recessive disease of childhood due to loss of the telomeric survival motor neuron gene, SMN1. The general functions of the main SMN1 protein product, full-length SMN (FL-SMN), do not explain the selective motoneuronal loss of SMA. We identified axonal-SMN (a-SMN), an alternatively spliced SMN form, preferentially encoded by the SMN1 gene in humans. The a-SMN transcript and protein are down-regulated during early development in different tissues. In the spinal cord, the a-SMN protein is selectively expressed in motor neurons and mainly localized in axons. Forced expression of a-SMN stimulates motor neuron axonogenesis in a time-dependent fashion and induces axonal-like growth in non-neuronal cells. Exons 2b and 3 are essential for the axonogenic effects. This discovery indicates an unexpected complexity of the SMN gene system and may help in understanding the pathogenesis of SMA.


Axons/physiology , Cell Differentiation/genetics , Cyclic AMP Response Element-Binding Protein/genetics , Nerve Tissue Proteins/genetics , Neurons/cytology , RNA-Binding Proteins/genetics , Amino Acid Sequence , Animals , Cell Survival/genetics , Cells, Cultured , Cyclic AMP Response Element-Binding Protein/physiology , Molecular Sequence Data , Nerve Tissue Proteins/physiology , Protein Isoforms/genetics , Protein Isoforms/physiology , RNA-Binding Proteins/physiology , Rats , SMN Complex Proteins , Spinal Cord/cytology , Spinal Cord/metabolism , Survival of Motor Neuron 1 Protein
6.
Neurobiol Dis ; 24(3): 429-42, 2006 Dec.
Article En | MEDLINE | ID: mdl-17027274

We examined the blood-brain barrier (BBB) function in methylazoxymethanol acetate (MAM)-treated rats, a model of human developmental brain malformations. We found aberrant vessels morphology and serum albumin leakage in the heterotopic (malformed) hippocampus; these changes were associated with a significant increase in endothelial P-glycoprotein (P-gp) expression. Seizures exacerbated BBB leakage and greatly augmented P-gp expression in vessels and additionally in perivascular/parenchymal astrocytes. The effects of seizures were observed to a much larger extent in malformed than in normal brain tissue. The intrinsic changes in BBB function in MAM-exposed rats were associated with increased blood-to-brain penetration of ondansetron, a P-gp substrate. However, a marked reduction in drug brain levels was provoked by seizures, and this effect was reversed by selective blockade of P-gp activity with tariquidar. Changes in BBB function may critically contribute to determine the brain uptake and distribution of P-gp substrates in epileptic tissue associated with developmental malformations.


ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Blood-Brain Barrier/metabolism , Endothelial Cells/metabolism , Epilepsy/metabolism , Hippocampus , Seizures/metabolism , ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Animals , Anticonvulsants/pharmacokinetics , Astrocytes/metabolism , Blood-Brain Barrier/drug effects , Brain/abnormalities , Brain/blood supply , Capillary Permeability/drug effects , Capillary Permeability/physiology , Choristoma/chemically induced , Disease Models, Animal , Drug Resistance/physiology , Endothelial Cells/drug effects , Epilepsy/pathology , Female , Male , Matched-Pair Analysis , Methylazoxymethanol Acetate , Ondansetron/pharmacokinetics , Pregnancy , RNA, Messenger/analysis , Rats , Seizures/pathology , Serum Albumin/metabolism
7.
J Neuropathol Exp Neurol ; 65(9): 883-93, 2006 Sep.
Article En | MEDLINE | ID: mdl-16957582

Altered excitatory synaptic activity is likely a key factor in the neuronal hyperexcitability of developmental cerebral malformations. Using a combined morphologic and molecular approach, we investigated the NMDA receptor and related protein composition in human epileptic patients affected by periventricular nodular heterotopia, subcortical band heterotopia, or focal cortical dysplasia. Our results indicate that expression levels of specific NMDA receptor subunits are altered in both cerebral heterotopia and cortical dysplasia. A selective increase in the NR2B subunit was present in all cortical dysplasia, whereas the expression level of NR2A and NR2B subunits was significantly downregulated in all patients with heterotopia. NR2B upregulation in cortical dysplasia was greater in the total homogenate than the postsynaptic membrane fraction, suggesting that mechanisms other than increased ionic influx through the postsynaptic membrane may sustain hyperexcitability in dysplastic neurons. In cerebral heterotopia, the NR2A and NR2B downregulation was accompanied by less evident reduction of the SAP97 and PSD-95 proteins of the MAGUK family, thus suggesting that NMDA impairment was associated with altered molecular structure of the postsynaptic membrane. Our results demonstrate that diverse human developmental malformations are associated with different alterations of the NMDA receptor, which may contribute to the genesis of epileptic phenomena.


Cerebral Cortex/abnormalities , Cerebral Cortex/metabolism , Receptors, N-Methyl-D-Aspartate/metabolism , Adolescent , Adult , Blotting, Western/methods , Brain Diseases/complications , Cerebral Cortex/pathology , Child , Doublecortin Domain Proteins , Epilepsy/etiology , Epilepsy/pathology , Female , Gene Expression , Humans , Immunohistochemistry/methods , Magnetic Resonance Imaging/methods , Male , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Nerve Tissue Proteins/metabolism , Neuropeptides/genetics , Neuropeptides/metabolism , Protein Subunits/metabolism , Receptors, N-Methyl-D-Aspartate/genetics
8.
Epilepsia ; 47(1): 86-97, 2006 Jan.
Article En | MEDLINE | ID: mdl-16417536

PURPOSE: Periventricular nodular heterotopia (PNH) is among the most common malformations of cortical development, and affected patients are frequently characterized by focal drug-resistant epilepsy. Here we analyzed clinical, MRI, and electrophysiologic findings in 54 PNH patients to reevaluate the classification of PNH, relate the anatomic features to epileptic outcome, and ascertain the contribution of PNH nodules to the onset of epileptic discharges. METHODS: The patients were followed up for a prolonged period at the Epilepsy Center of our Institute. In all cases, we related MRI findings to clinical and epileptic outcome and analyzed interictal and ictal EEG abnormalities. In one patient, EEG and stereo-EEG (SEEG) recordings of seizures were compared. RESULTS: We included cases with periventricular nodules, also extending to white matter and cortex, provided that anatomic continuity was present between nodules and malformed cortex. Based on imaging and clinical data, patients were subdivided into five PNH groups: (a) bilateral and symmetrical; (b) bilateral single-noduled; (c) bilateral and asymmetrical; (d) unilateral; and (e) unilateral with extension to neocortex. The latter three groups were characterized by worse epileptic outcome. No differences in outcome were found between unilateral PNH patients regardless the presence of cortical involvement. Interictal as well as ictal EEG abnormalities were always related to PNH location. CONCLUSIONS: The distinctive clinical features and epileptic outcomes in each group of patients confirm the reliability of the proposed classification. Ictal EEG and SEEG recordings suggest that seizures are generated by abnormal anatomic circuitries including the heterotopic nodules and adjacent cortical areas.


Cerebral Cortex/abnormalities , Choristoma/complications , Epilepsy/etiology , Adolescent , Adult , Brain Mapping , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Cerebral Ventricles/abnormalities , Cerebral Ventricles/pathology , Child , Child, Preschool , Choristoma/physiopathology , Electrodes, Implanted , Electroencephalography/methods , Electroencephalography/statistics & numerical data , Epilepsies, Partial/diagnosis , Epilepsies, Partial/etiology , Epilepsies, Partial/physiopathology , Epilepsy/diagnosis , Epilepsy/pathology , Female , Follow-Up Studies , Functional Laterality , Humans , Infant , Magnetic Resonance Imaging , Male , Middle Aged , Nervous System Malformations/classification , Nervous System Malformations/pathology , Nervous System Malformations/physiopathology , Outcome Assessment, Health Care , Stereotaxic Techniques
9.
J Child Neurol ; 20(4): 369-77, 2005 Apr.
Article En | MEDLINE | ID: mdl-15921241

Patients affected by periventricular nodular heterotopia are frequently characterized by focal drug-resistant epilepsy. To investigate the role of periventricular nodules in the genesis of seizures, we analyzed the electroencephalographic (EEG) features of focal seizures recorded by means of video-EEG in 10 patients affected by different types of periventricular nodular heterotopia and followed for prolonged periods of time at the epilepsy center of our institute. The ictal EEG recordings with surface electrodes revealed common features in all patients: all seizures originated from the brain regions where the periventricular nodular heterotopia were located; EEG patterns recorded on the leads exploring the periventricular nodular heterotopia were very similar both at the onset and immediately after the seizure's end in all patients. Our data suggest that seizures are generated by abnormal anatomic circuitries, including the heterotopic nodules and adjacent cortical areas. The major role of heterotopic neurons in the genesis and propagation of epileptic discharges must be taken into account when planning surgery for epilepsy in patients with periventricular nodular heterotopia.


Cerebral Ventricles/abnormalities , Cerebral Ventricles/physiopathology , Choristoma/complications , Choristoma/physiopathology , Epilepsies, Partial/etiology , Epilepsies, Partial/physiopathology , Adolescent , Adult , Cerebral Cortex/pathology , Cerebral Cortex/physiopathology , Choristoma/pathology , Electroencephalography , Epilepsies, Partial/pathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies
10.
Epileptic Disord ; 5 Suppl 2: S51-8, 2003 Sep.
Article En | MEDLINE | ID: mdl-14617421

The pre-natal administration of methylazoxymethanol acetate (MAM) in rats is able to induce cerebral heterotopia that share striking similarities with those observed in human periventricular nodular heterotopia, a cerebral dysgenesis frequently associated with drug-resistant focal seizures. In the present study, we investigated the mode of neurogenesis in cerebral heterotopia of MAM-treated rats, by analyzing post-natal cytoarchitectural features and time of neurogenesis using bromodeoxyuridine immunocytochemistry. The cytoarchitectural analysis demonstrated the existence, in the early post-natal period, of white matter cellular bands in close anatomical relationship with the heterotopia, which most likely serve as a reservoir of young, migrating neurons for the newly forming heterotopia. The birth dating analysis demonstrated that the period of generation of neurons within the heterotopia and adjacent white matter bands, was extended in comparison to corticogenesis in normal rat brains. In addition, it demonstrated that the heterotopia were formed through a rather precise outside-in (for cortical and periventricular heterotopia) and dorso-ventral (for intra-hippocampal heterotopia) neurogenetic pattern. We hypothesize that the MAM-induced ablation of an early wave of cortical neurons is sufficient to alter per se the migration and differentiation of subsequently generated neurons, which in turn set the base for the formation of the different types of heterotopia. On this basis, we suggest a neurogenetic scheme for MAM-induced heterotopia that can also explain the origin and intrinsic epileptogenicity of periventricular nodular heterotopia in humans.


Brain Diseases/complications , Brain Diseases/pathology , Choristoma/complications , Choristoma/pathology , Epilepsy/etiology , Animals , Brain Diseases/chemically induced , Cell Movement/physiology , Choristoma/chemically induced , Female , Immunohistochemistry , Methylazoxymethanol Acetate/administration & dosage , Methylazoxymethanol Acetate/adverse effects , Neurons/drug effects , Neurons/pathology , Protein Synthesis Inhibitors/administration & dosage , Protein Synthesis Inhibitors/adverse effects , Rats , Rats, Sprague-Dawley
11.
J Neuropathol Exp Neurol ; 62(6): 662-75, 2003 Jun.
Article En | MEDLINE | ID: mdl-12834111

Double intraperitoneal injections of methylazoxymethanol (MAM) in pregnant rats induce developmental brain dysgenesis with nodular heterotopia similar to human periventricular nodular heterotopia (PNH) and composed of hyperexcitable neurons. Here we analyzed the NMDA receptor complex and associated proteins in the heterotopic neurons of 2- to 3-month-old MAM-treated rats by means of a combined immunocytochemical/molecular approach. Our data demonstrated a clear reduction of p286-active form of alphaCaMKII and a selective impairment of both the targeting and the CaMKII-dependent phosphorylation of NR2A/B subunits in the postsynaptic membranes of the MAM-induced heterotopia. The reduced NR2A/B immunofluorescence of the cellular membrane was not due to reduced expression since it was decreased only in postsynaptic fractions but not in the homogenate. NMDA-NR1 and AMPA-GluR2/3 subunits, as well as PSD-95 and total alphaCaMKII protein levels, were not affected in MAM-treated rats, thus revealing that the overall composition of the postsynaptic fraction was not altered. These data clearly suggest that the molecular organization of the NMDA/alphaCaMKII complex is selectively altered in the postsynaptic compartment of heterotopic neurons. This alteration can play a role in determining the hyperexcitability of brain heterotopia in MAM rats as well as in human patients affected by PNH.


Cerebral Cortex , Choristoma/pathology , Methylazoxymethanol Acetate/analogs & derivatives , Receptors, N-Methyl-D-Aspartate/metabolism , Animals , Animals, Newborn , Autoradiography/methods , Blotting, Western , Calcium-Calmodulin-Dependent Protein Kinase Type 2 , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Carcinogens/toxicity , Cell Membrane/metabolism , Cell Membrane/pathology , Choristoma/chemically induced , Choristoma/metabolism , Cloning, Molecular/methods , Disease Models, Animal , Disks Large Homolog 4 Protein , Female , Hippocampus/metabolism , Hippocampus/pathology , Humans , Immunohistochemistry , Intracellular Signaling Peptides and Proteins , Male , Matched-Pair Analysis , Membrane Proteins , Methylazoxymethanol Acetate/toxicity , Microscopy, Confocal/instrumentation , Microscopy, Confocal/methods , Nerve Tissue Proteins/metabolism , Peptide Fragments/immunology , Peptide Fragments/metabolism , Phosphorylation , Pregnancy , Rats , Receptors, AMPA/metabolism , Receptors, N-Methyl-D-Aspartate/classification , Subcellular Fractions/metabolism
12.
Cereb Cortex ; 13(7): 736-48, 2003 Jul.
Article En | MEDLINE | ID: mdl-12816889

We have previously demonstrated that the antiproliferative agent methylazoxymethanol acetate (MAM) is able to induce in rats cerebral heterotopia that share striking similarities with those observed in human periventricular nodular heterotopia (PNH), a cerebral dysgenesis frequently observed in human patients affected by drug-resistant focal epilepsy. In this study, we investigated the time-course of neurogenesis in the cerebral heterotopia of MAM-treated rats, with the idea of understanding why PNH develop in human patients. For these goals, we analyzed the cytoarchitectural features, the time of neurogenesis and the cellular phenotype of the heterotopia, by means of BrdU immunocytochemistry and confocal immunofluorescence experiments. Our data demonstrate that the different types of heterotopia in MAM-treated rats are formed through the same altered neurogenetic process, which follows quite organized neurogenetic gradients. The MAM-induced ablation of an early wave of cortical neurons is sufficient to alter per se the migration and differentiation of subsequently generated neurons, which in turn set the base for the formation of the different heterotopic structures. The neurogenesis of MAM-induced heterotopia may explain the origin and intrinsic epileptogenicity of periventricular nodular heterotopia in human patients.


Brain Diseases/embryology , Brain Diseases/pathology , Cerebral Cortex , Choristoma/embryology , Choristoma/pathology , Methylazoxymethanol Acetate/analogs & derivatives , Animals , Brain Diseases/chemically induced , Brain Diseases/genetics , Bromodeoxyuridine , Choristoma/chemically induced , Choristoma/genetics , Disease Models, Animal , Female , Microscopy, Confocal , Morphogenesis , Neurons/drug effects , Neurons/pathology , Phenotype , Pregnancy , Rats , Rats, Sprague-Dawley
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