Early ethanol pre-exposure alters breathing patterns by disruptions in the central respiratory network and serotonergic balance in neonate rats

Moderate ethanol exposure during early ontogeny of the rat alters respiratory plasticity, ultrasonic distress vocalizations, increases brain catalase activity, and acetaldehyde-mediated ethanol intake

“…Ethanol’s first metabolite role was assayed along with the activity of brain catalase system during this stage of development. In line with previous findings ( Cullere et al, 2015 ; Acevedo et al, 2017a ; Macchione et al, 2018 , 2021 ), we observed that early exposure to ethanol sensitizes pups to ethanol’s respiratory depressant effects upon breathing patterns and increases apneic episodes ( Figures 2A,B ). In addition, pups showed lower breathing frequencies until an apneic episode occurred (coefficient breaths/apneas, Figure 2C ).…”

“…response to low oxygen environment in neonates, infants, and adults (Dubois et al, 2006(Dubois et al, , 2008(Dubois et al, , 2013Kervern et al, 2009;Dubois and Pierrefiche, 2020). However, while effects on the respiratory system seems due to chronic exposure to ethanol, our data along with recent studies show that brief fetal and neonatal experiences with a moderate ethanol dose are sufficient to functionally disrupt the respiratory plasticity of the organisms under associative and non-associative learning processes (Cullere et al, 2015;Macchione et al, 2016Macchione et al, , 2018Macchione et al, , 2021Acevedo et al, 2017a;D'aloisio et al, 2020;Anunziata et al, 2021).…”

“…In addition, pups showed lower breathing frequencies until an apneic episode occurred (coefficient breaths/apneas, Figure 2C ). Regardless of the treatment’s nature, a transient decrease in breathing frequencies ( Figure 2A ) was observed throughout evaluations, indicative of a habituation process ( Macchione et al, 2016 , 2018 , 2021 ; Acevedo et al, 2017a , b ; D’aloisio et al, 2020 ; Trujillo et al, 2020 ). The short and long-term effects of ethanol on neonatal respiratory plasticity more recently have received attention given the association between fetal alcohol exposure and the sudden infant death syndrome ( Iyasu et al, 2002 ; Burd et al, 2004 ; Bailey and Sokol, 2011 ; O’Leary et al, 2013 ).…”

“…One basal minute was considerate to allow air pressure stabilization. These experimental procedures have been previously used to assess breathing patterns as function of ethanol exposure during pre- and postnatal period ( Cullere et al, 2015 ; Macchione et al, 2016 , 2018 , 2021 ; Acevedo et al, 2017a , b ; D’aloisio et al, 2020 ; Anunziata et al, 2021 ).…”

“…Such early experiences not only generate sensitivity to the positive motivational effects of ethanol but also sensitize the organism to the consequences of ethanol upon respiratory plasticity. Brief experiences with moderate doses of ethanol during late gestation (Cullere et al, 2015) or within the first postnatal week that generate respiratory disruptions indicative of sensitization processes (Cullere et al, 2015;Macchione et al, 2016Macchione et al, , 2018Macchione et al, , 2021Acevedo et al, 2017a;D'aloisio et al, 2020). Moreover, the association of a salient odor stimulus (e.g., ethanol) in the presence of ethanol-related respiratory disruptions, elicit later conditioned breathing depressions and increase the occurrence of apneic episodes (Cullere et al, 2015;Macchione et al, 2016Macchione et al, , 2018.…”