title: Aging causes morphological alterations in astrocytes and microglia in human substantia nigra pars compacta.
abstract: Age being a risk factor for Parkinson's disease, assessment of age-related changes in the human substantia nigra may elucidate its pathogenesis. Increase in Marinesco bodies, α-synuclein, free radicals and so forth in the aging nigral neurons are clear indicators of neurodegeneration. Here, we report the glial responses in aging human nigra. The glial numbers were determined on Nissl-stained sections. The expression of glial fibrillary acidic protein, S100β, 2', 3'-cyclic nucleotide 3' phosphodiesterase, and Iba1 was assessed on cryosections of autopsied midbrains by immunohistochemistry and densitometry. The glial counts showed a biphasic increase, of which, the first prominent phase from fetal age to birth could be physiological gliogenesis whereas the second one after middle age may reflect mild age-related gliosis. Astrocytic morphology was altered, but glial fibrillary acidic protein expression increased only mildly. Presence of type-4 microglia suggests possibility of neuroinflammation. Mild reduction in 2', 3'-cyclic nucleotide 3' phosphodiesterase-labeled area denotes subtle demyelination. Stable age-related S100β expression indicates absence of calcium overload. Against the expected prominent gliosis, subtle age-related morphological alterations in human nigral glia attribute them a participatory role in aging.
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: H J
authors.initials: HJ
authors.lastname: Jyothi
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: D J
authors.initials: DJ
authors.lastname: Vidyadhara
authors.affiliation: Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Mahadevan
authors.affiliation: Department of Biostatistics, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: Mariamma
authors.initials: M
authors.lastname: Philip
authors.affiliation: Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: Suresh Kumar
authors.initials: SK
authors.lastname: Parmar
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: S Gowri
authors.initials: SG
authors.lastname: Manohari
authors.affiliation: Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Shankar
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India.
authors.forename: Trichur R
authors.initials: TR
authors.lastname: Raju
authors.affiliation: Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bengaluru, India. Electronic address: alladiphalguni@gmail.com.
authors.forename: Phalguni Anand
authors.initials: PA
authors.lastname: Alladi
mesh_terms: D063309:2',3'-Cyclic Nucleotide 3'-Phosphodiesterase / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology*; D002118:Calcium / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007223:Infant; D008297:Male; D017628:Microglia / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D009410:Nerve Degeneration; D020078:Neurogenic Inflammation; D010300:Parkinson Disease; D065842:Pars Compacta / Q000166:cytology* / Q000473:pathology*; D012307:Risk Factors; D064568:S100 Calcium Binding Protein beta Subunit / Q000378:metabolism; D055815:Young Adult
chemical_list: D005904:Glial Fibrillary Acidic Protein; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human; D063309:2',3'-Cyclic Nucleotide 3'-Phosphodiesterase; D002118:Calcium
keywords: Autopsied human midbrains; CNPase; Densitometry; GFAP; Iba1; Morphometry; Parkinson's disease; S100β; Stereology