Role Of GABA_A Receptors In Pentobarbital-depressed Respiration Of Neonatal Rat Medullary Slices In Vitro

Object:Barbiturates modulate respiratory frequency, tidal volume, volume per minute. However, the mechanism of modulation of respiration is not clearly understood so far. We used the medullary slice preparations and en bloc preparations from neonatal rats to study how barbiturates modulate respiration via recording respiratory-related rhythmic discharge activities (RRDA) and discharge activities of inspiratory neurons located in the medial are of retrofacialis nucleus (mNRF). Pentobarbital sodium (Pento) and bicuculline (BIC) were bath-applied to test the hypothesis that pentobarbital-depressed respiratory-related rhythmic activities are mediated via GABA_a receptors.Methods1. AnimalsSixty neonatal Sprague-Dawley rats born by spontaneous vaginal delivery were used in this study. All procedures were approved and performed in accordance with guidelines provided by the Institutional Animal Care and Use Committee at the university of China.2. Medullary slice preparations and en bloc preparations0—3 days neonatal rats were used. Some rats were used for medullary slice preparations and some for en bloc preparations.