Salcedo-Rosado, A. Figueroa-Pérez, M. Cáceres-Chacón, O. Martínez-Guzmán, D. Sierra-Mercado

Key words: glyphosate, anxiety, insula, behaviors

INTRODUCTION:Glyphosate, the active ingredient in various commercial herbicides, is considered a contaminant that can be present in food and water. Our group aims to investigate the effects of prolonged exposure to a daily dose of 2.0 mg/kg of glyphosate, which was deemed safe by the Environmental Protection Agency (EPA). The findings of our laboratory suggest that EPA reference dose leads to an increase in anxiety-like behaviors. We examined the cellular activity in specific subregions of the insula, a brain area involved in anxiety modulation.

METHODS: To accomplish this, rats were exposed to glyphosate for 16 weeks. Next, rats were sacrificed, and brain tissue containing the insula subregions—agranular insula dorsal and ventral (AID/AIV), granular insula (GID), and disgranular insula (DI)—was extracted. C-Fos immunohistochemistry was conducted on the brain slices to assess cellular activity.

RESULTS: Preliminary results indicate that glyphosate does not lead to a significantly decrease in the cellular activity in the insula (p=0.6646). However, there is a tendency for decreased cellular activity in the AID region (p=0.0649).

CONCLUSION: These findings contribute to the understanding of the potential neurotoxic effects associated with glyphosate consumption. Further research directions include dissociating between the caudal insula regions, known for their anxiolytic roles, as well as the rostral (frontal) regions, known for their anxiogenic roles (Mendez-Ruette et al., 2019).

IACUC APPROVAL NUMBER: A120418

ACKNOWLEDGMENTS: NIEHS R21ES034191 to DS-M and FG-V; NINDS R21NS119991, Brain & Behavior Research Foundation Young Investigator grant, PRCTRC Pilot, NIGMS COBRE II, and RCMI8G12MD00760 to DS-M; NSF PRCEN fellowships to MC-C, MR-L& HH-M, Neuro-ID fellowship 5R25NS080687 to TS-R, AF-P & GH-B, UPR Med Sci Campus Chancellor’s Office and School of Medicine Deanship