Glyphosate commercial formulation effects on preoptic area and hypothalamus of Cardinal Neon Paracheirodon axelrodi (Characiformes: Characidae)

Abstract

In Colombia the use of glyphosate commercial formulations (Roundup™) for spraying have left deleterious effects on animals and humans. Much of this spraying takes place at the Orinoco basin, habitat of one of the most exported ornamental fish in Colombia, Cardinal neon. To evaluate the effect of Roundup Activo™ four experimental treatments were carried out with 0 mg/L (T1), 0.1 mg/L (T2), 1 mg/L (T3) and 5 mg/L (T4) during 30 days of exposure. The fishes were processed for high-resolution optical microscopy. The main finding of Roundup Activo™ exposure was an increase in mast cells number in brain blood vessels and some neuronal nuclei of the preoptic and posterior diencephalic areas, including hypothalamus. A correlation between concentrations and mast cells number was observed, with the largest mast cells number in T4 treatment. Mast cells presence is a stress benchmark, suggesting the beginning of allergic, inflammatory and apoptotic events. Presence of mast cells in these brain areas may lead to alterations on reproduction, visual and olfactory information integration among other processes. These alterations may result in diminished survival, affecting the conservation of this species in its natural habitat.

Histology and ultrastructure of the digestive system in Andean fish (Trichomycterus bogotensis) and ecological implications

“…Another two sh were xed in Karnovsky and post-xed in 2.5% osmium tetroxide for high-resolution optical microscopy (HROM) and transmission electron microscopy (TEM). Subsequently, samples were dehydrated with a series of ethanol solutions at increasing concentrations (70%, 80%, 90%, and 100%), embedded in Poly/Bed 812® resin sectioned at 1mm with a rotary microtome (CUT SLEE 4060®), and stained with toluidine blue (Riaño et al, 2019). For ultrastructure analysis by TEM, tissue samples were sectioned into ultrathin 150 nm sections using ultramicrotome Leica® EM UC6.…”

Glyphosate, AMPA and glyphosate-based herbicide exposure leads to GFAP, PCNA and caspase-3 increased immunoreactive area on male offspring rat hypothalamus

“…11,18 It has been reported that the number of mastocytes increased in the preoptic area of the adult fish Paracheirodon axelrodi after exposure to a Roundup ® solution containing 1-5 mg/L glyphosate. 15 In tadpoles, after exposure to glyphosate formulations (0.21 mg/L), changes in metamorphosis were observed as well as a diminished brain THR alpha and beta expression and an increased Dio2/Dio3 expression were also reported. 19 In adult rats, diminished levels of follicle stimulating hormone and testosterone coupled to increased levels of luteinizing hormone and estrogens have been reported after glyphosate exposure (400 or 2000 mg/kg/day).…”

“…1,[12][13][14] Pesticides, including glyphosate-based herbicides, have been widely used in agriculture for weed control, grain drying and fumigation of transgenic crops. [15][16][17] Data, obtained from several vertebrate species, strongly indicate that glyphosate and its commercial formulations act as endocrine disruptors by altering the hypothalamic-pituitaryendocrine axis. For example, the levels of key molecules involved in reproductive mechanisms are altered to different degrees.…”