Long-term consequences of early postnatal lead exposure on hippocampal synaptic activity in adult mice.

Autor: Tena A; Department of Biological Sciences, College of Science, University of Texas at El Paso, El Paso, Texas., Peru E; Department of Biological Sciences, College of Science, University of Texas at El Paso, El Paso, Texas., Martinetti LE; Department of Biological Sciences, College of Science, University of Texas at El Paso, El Paso, Texas., Cano JC; Department of Biological Sciences, College of Science, University of Texas at El Paso, El Paso, Texas., Loyola Baltazar CD; Department of Biological Sciences, College of Science, University of Texas at El Paso, El Paso, Texas., Wagler AE; Department of Mathematical Sciences, College of Science, University of Texas at El Paso, El Paso, Texas., Skouta R; Department of Chemistry, College of Natural Science, University of Massachusetts Amherst, Amherst, Massachusetts., Fenelon K; Department of Biological Sciences, College of Science, University of Texas at El Paso, El Paso, Texas.; Biology Department, College of Natural Science, University of Massachusetts Amherst, Amherst, Massachusetts.
Jazyk: angličtina
Zdroj: Brain and behavior [Brain Behav] 2019 Aug; Vol. 9 (8), pp. e01307. Date of Electronic Publication: 2019 Jul 03.
DOI: 10.1002/brb3.1307
Abstrakt: Introduction: Lead (Pb) exposure yielding blood lead levels (BLL) as low as 2 µg/dl in children is an international problem. More common in US low-income neighborhoods, childhood Pb exposure can cause behavioral and cognitive deficits, including working memory impairments, which can persist into adulthood. So far, studies characterized short-term effects of high Pb exposure on neuronal structure and function. However, long-term consequences of early chronic Pb exposure on neuronal activity are poorly documented.
Methods: Here, we exposed male and female mice (PND [postnatal day] 0 to PND 28) to one of three Pb treatments: 0 ppm (sodium-treated water, control), 30 ppm (low dose), and 330 ppm (high dose) lead acetate. Once the male and female mice were 9-12 months old, extracellular field recordings on hippocampal slices were performed.
Results: We show that at CA3 to CA1 synapses, synaptic transmission was decreased and neuronal fiber activity was increased in males exposed to lowest level Pb. In contrast, both synaptic transmission and neuronal fiber activity were increased in females exposed to high Pb. The ventral hippocampus-medial prefrontal cortex (vHPC-mPFC) synapses are crucial for working memory in rodents. The lowest level Pb decreased vHPC-mPFC synaptic transmission, whereas high Pb decreased short-term synaptic depression.
Conclusions: Overall, we show for the first time that early exposure to either high or lowest level Pb has long-term consequences on different synaptic properties of at least two hippocampal synapses. Such consequences of early Pb exposure might worsen the cognitive decline observed in aging men and women. Our results suggest that additional efforts should focus on the consequences of early Pb exposure especially in at-risk communities.
(© 2019 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.)
Databáze: MEDLINE
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