title: Long-term astroglial reaction and neuronal plasticity in the subcortical visual pathways after a complete ablation of telencephalon in pigeons (Columba livia).
abstract: This paper analyzes the astroglial and neuronal responses in subtelencephalic structures, following a bilateral ablation of the telencephalon in the Columba livia pigeons. Control birds received a sham operation. Four months later the birds were sacrificed and their brains processed for glial fibrillary acid protein (GFAP) and neurofilament immunohistochemistry, markers for astrocytes and neurons, respectively. Computer-assisted image analysis was employed for quantification of the immunoreactive labeling in the nucleus rotundus (N.Rt) and the optic tectum (OT) of the birds. An increased number of GFAP immunoreactive astrocytes were found in several subregions of the N.Rt (p< .001), as well as in layers 1, 2cd, 3, and 6 of the OT (p< .001) of the lesioned animals. Neurofilament immunoreactivity decreased massively in the entire N.Rt of the lesioned birds; however, remaining neurons with healthy aspect showing large cytoplasm and ramified branches were detected mainly in the periphery of the nucleus. In view of the recently described paracrine neurotrophic properties of the activated astrocytes, the data of the present study may suggest a long-lasting neuroglial interaction in regions of the lesioned bird brain far from injury. Such events may trigger neuronal plasticity in remaining brain structures that may lead spontaneous behavior recovery as the one promoted here even after a massive injury.
authors.affiliation: Neuroregeneration Center, Department of Neurology, University of Sao Paulo School of Medicine, Sao Paulo, Brazil.
authors.forename: Suzete Maria
authors.initials: SM
authors.lastname: Cerutti
authors.forename: Vânia Canterucci
authors.initials: VC
authors.lastname: Gomide
authors.forename: Elenis A
authors.initials: EA
authors.lastname: de Moraes Ferrari
authors.forename: Gerson
authors.initials: G
authors.lastname: Chadi
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001931:Brain Mapping; D010856:Columbidae / Q000033:anatomy & histology / Q000502:physiology*; D003714:Denervation; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis / Q000378:metabolism; D005911:Gliosis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D019044:Image Cytometry; D007150:Immunohistochemistry; D008297:Male; D016900:Neurofilament Proteins / Q000032:analysis / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D013045:Species Specificity; D013194:Staining and Labeling; D013477:Superior Colliculi / Q000033:anatomy & histology / Q000502:physiology; D013687:Telencephalon / Q000033:anatomy & histology / Q000502:physiology*; D013788:Thalamus / Q000033:anatomy & histology / Q000502:physiology; D013997:Time Factors; D014795:Visual Pathways / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; D016900:Neurofilament Proteins