Effect of penicillin on impulse activity of medullar neurons

Acute experiments on narcotized rats showed that intracerebral injection of penicillin increased the mean discharge rate in neurons of the bulbar respiratory center and neurons with rhythmic activity in the gigantocellular nucleus of the medulla oblongata. It also increased the number of neurons with high-frequency bursting activity. In most inspiratory neurons penicillin prolonged the discharges and increased the number of spikes in bursts. The population of inspiratory neurons became hyperactive and suppressed activity of expiratory neurons.