Inactivity and Ca signaling regulate synaptic compensation in motoneurons following hibernation in American bullfrogs.

Neural networks tune synaptic and cellular properties to produce stable activity. One form of homeostatic regulation involves scaling the strength of synapses up or down in a global and multiplicative manner to oppose activity disturbances. In American bullfrogs, excitatory synapses scale up to regulate breathing motor function after inactivity in hibernation, connecting homeostatic compensation to motor behavior.

Characterization of laryngeal motor neuron properties in the American bullfrog, Lithobates catesbieanus.

Motor neurons represent the final output from the central respiratory network. American bullfrogs, Lithobates catesbieanus, have provided insight into development and plasticity of the breathing control system, yet cellular aspects of bullfrog motor neurons are not well-described. In this study, we characterized properties of laryngeal motor neurons that produce motor outflow to the glottal dilator, a muscle that gates airflow to the lungs of anurans.

Neuromodulation or energy failure? Metabolic limitations silence network output in the hypoxic amphibian brainstem.

Hypoxia tolerance in the vertebrate brain often involves chemical modulators that arrest neuronal activity to conserve energy. However, in intact networks, it can be difficult to determine whether hypoxia triggers modulators to stop activity in a protective manner or whether activity stops because rates of ATP synthesis are insufficient to support network function. Here, we assessed the extent to which neuromodulation or metabolic limitations arrest activity in the respiratory network of bullfrogs-a circuit that survives moderate periods of oxygen deprivation, presumably, by activating an inhibitory noradrenergic pathway.

The Inhibitory Effect of Essential Oils on Rhizopus stolonifer, Trichophyton mentagrophytes, and Microsporum gypseum.

Background: Rhizopus stolonifer is an opportunistic fungus that causes respiratory infections, sinusitis, and otomycosis. Trichophyton mentagrophytes and Microsporum gypseum cause athlete's foot, ringworm, and nail infections. Previous research has shown that some essential oils inhibit fungal growth.