Open AccessPreliminary morphological and immunohistochemical changes in rat hippocampus following postnatal exposure to sodium arsenite
Author(s) -
Saroj Kaler,
Pushpa Dhar,
Aniruddha Bhattacharya,
Reeti Mehra
Publication year - 2013
Publication title -
toxicology international/indian journal of toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.129
H-Index - 26
eISSN - 0976-5131
pISSN - 0971-6580
DOI - 10.4103/0971-6580.117259
Subject(s) - dentate gyrus , sodium arsenite , tunel assay , cresyl violet , subgranular zone , pyramidal cell , hippocampal formation , granule cell , programmed cell death , hippocampus , chemistry , intraperitoneal injection , apoptosis , terminal deoxynucleotidyl transferase , biology , granule (geology) , endocrinology , pathology , microbiology and biotechnology , staining , biochemistry , arsenic , medicine , neural stem cell , stem cell , paleontology , organic chemistry , subventricular zone
The effects of arsenic exposure during rapid brain growth period (RBGP) (postnatal period 4-11) on pyramidal neurons of cornu ammonis (specifically CA1 and CA3 regions) and granule cells of dentate gyrus (DG) of rat hippocampus were studied. Wistar rat pups, subdivided into the control (group I) and the experimental groups (group II, III, and IV), received distilled water and sodium arsenite (aqueous solution of 1.0, 1.5, and 2.0 mg/kg body weight, respectively) by intraperitoneal (i.p.) route. On postnatal day (PND) 12, the animals were sacrificed and brain tissue obtained. Paraffin sections (8 μm thick) stained with Cresyl Violet (CV) were observed for morphological and morphometric parameters. Arsenic induced programmed cell death (apoptosis) was studied using Terminal deoxyribonucleotidyl transferase mediated dUTP biotin Nick End Labeling (TUNEL) technique on the paraffin sections. Microscopy revealed decreased number and isolation of pyramidal neurons in superficial layers, misalignments of pyramidal cells in stratum pyramidale (SP) of CA1 and CA3 in experimental group III and IV, and presence of polymorphic cells in subgranular zone of ectal limb of dentate gyrus (suggestive of arsenic induced proliferation and migration of granule cells in the dentate gyrus). Morphometric assessments quantified and confirmed the microscopic findings. The mean nuclear area of pyramidal cells was increased and cell density was decreased in the CA1, CA3, and DG of experimental groups in comparison to the control group. Increase in the TUNEL positive cells in DG was observed in the experimental group IV, suggestive of increased apoptosis. These observations confirm vulnerability of pyramidal (CA1, CA3) and granule cells (DG) of hippocampus during RBGP.