cAMP-dependent protein kinase modulates expiratory neurons in vivo.

Lalley, Peter M., Olivier Pierrefiche, Anne M. Bischoff, and Diethelm W. Richter. cAMP-dependent protein kinase modulates expiratory neurons in vivo. J. Neurophysiol. 77: 1119–1131, 1997. The adenosine 3′,5′-cyclic monophosphate (cAMP)-dependent protein kinase (PKA) second-messenger system influences neuronal excitability by modulating voltage-regulated and transmitter-activated channels. In this study we investigated the influence of the cAMP-PKA system on the excitability of expiratory (E) neurons in the caudal medulla of anesthetized, paralyzed, and artificially ventilated adult cats. We intracellularly injected the PKA inhibitors cAMP-dependent PKA inhibitor 5-22 amide (Walsh inhibitory peptide) and Rp-adenosine 3′,5′-cyclic monophosphothioate triethylamine (Rp-cAMPS), the PKA activator Sp-adenosine 3′,5′-cyclic monophosphothioate triethylamine (Sp-cAMPS), and the adenylyl cyclase activator forskolin and measured membrane potential, neuronal input resistance, and synaptic membrane currents. Inhibition...