Long-Term Behavioral Consequences of Prenatal Binge Toluene Exposure in Adolescent Rats

Abstract

The continued abuse of inhaled organic solvents, especially among women of childbearing age, raises the risk of long-term behavioral effects of maternal toluene abuse. In this study, the effects of short-term exposures to high toluene concentrations (i.e., "binges") were tested in independent groups of adolescent rats with different toluene treatments: (a) acute: 30-day-old animals exposed for 30 min to air (A) or 6,000 ppm toluene (T); (b) prenatal and postnatal: rats exposed to T or A from gestation days 8-20 and re-exposed to T or A from postnatal day (PN) 22 to PN30 (A/A, T/A, A/T, and T/T, resp.). On PN30, animals were evaluated in different tests. Postnatal toluene exposure produced anxiolytic-like effects in the burying behavior test, and the T/T group received the highest number of electrical shocks. Antinociception was observed in the T, A/T, and T/T groups in the hotplate test. All toluene treatments impaired short-term memory in the object recognition test, but only postnatal exposure impaired long-term memory in the passive avoidance test. Sensitization occurred in the T/T group in locomotor activity. These results indicate that prenatal exposure to a concentration of toluene that does not produce evident malformations can modify behavioral toluene's effects in adolescent rats.

Prenatal Exposure to Paint Thinner Alters Postnatal Development and Behavior in Mice

“…These observations are compatible with findings by Hass et al ( 1995 , 1999 ) who showed that the mnemonic processes are particularly vulnerable to xylene and toluene effects. Additionally, similar results have been demonstrated by other experimental tests (i.e., the object recognition test and the Morris water maze task), which involve short-term memory or spatial learning (Fifel et al, 2014 ; López-Rubalcava et al, 2014 ; Callan et al, 2015 ). No mechanistic studies have been designed to find out the molecular targets implicated in cognitive impairments, but changes in the expression of NMDA receptor (subunits NR1 and NR2 mRNA), NMDA receptor antagonism, and inhibition of neurogenesis in the hippocampus could be associated with the impaired memory observed in mice exposed to thinner during gestation (Seo et al, 2010 ; Huerta-Rivas et al, 2012 ; Win-Shwe and Fujimaki, 2012 ).…”