Exposure to methamidophos at adulthood adversely affects serotonergic biomarkers in the mouse brain

► Methamidophos at adulthood elicits robust decreases in binding for all 5HT markers. ► Organophosphates can promote changes in serotonergic function even at adulthood. ► Serotonergic changes can clarify the link between organophosphates and depression. ► Harmful effects of organophosphates are not restricted to cholinesterase inhibition.