On the excitation and inhibition of the inspiratory neuron in the respiratory centers

In decerebrated cats the impulse discharges were detected by means of an unipolar microelectrode from a single inspiratory neuron in the respiratory centers, and the change in discharge produced by administration of stimulating, as well as depressant agents, was studied. The results were summarized as follows. 1) Inhalation of the air containing all. excess of carbon dioxide, as well as the air deficient of oxygen and the intravenous administration of a small dose of caffeine, aminocordine and lobeline produced a) a remarkable increase of frequency of impulses in the stage of constant frequency of the volley, b) a rapid increase of frequency of impulses in the stage of crescent frequency of the volley and c) a shortening of the duration of the volleys, as well as of silent periods. 2) In narcosis by a moderate dose of morphine, as well as in the recovery stage from apnea produced by over-ventilation, there were observed the phenomena which were exactly opposite to those described in 1). 3) It was concluded that a most essential sign by which one can discern whether the activity of the respiratory Genters is raised or depressed, is the changes of the frequency of impulses produced from an inspiratory neuron. The expense of this research was defrayed from the grant in aid of the Ministry of Education.</p

Shear viscosity of the quark matter

We discuss shear viscosity of the quark matter by using Kubo formula. The shear viscosity is calculated in the framework of the quasi-particle RPA for the Nambu-Jona-Lasinio model. We obtain a formula that the shear viscosity is expressed by the quadratic form of the quark spectral function in the chiral symmetric phase. The magnitude of the shear viscosity is discussed assuming the Breit-Wigner type for the spectral function.Comment: 5 pages, 6 figure

The action of atropine and acetylcholine on the pace maker ganglion cells of limulus heart

On the median nerve trunk-heart muscle preparation of Limulus the authors studied the effects of atropine and acetylcholine upon the pace maker ganglion cells. The results are summarized as follows: (1) Atropine exerts an excitatory action on the pace maker ganglion cells in a concentration of 1-2 per cent. resulting in an increase of the heart rate. No effect is recognized on the heart beats, where the drug is applied to the heart muscle. (2) Acetylcholine exerts an excitatory action in a lower concentration (0.001-0.10 %) and produces a transitory excitation followed by an inhibition in a higher concentration (1-5 %). No effect is perceptible on the heart beats, when the drug is applied to the heart muscle. (3) Where atropine has been previously applied to the median nerve trunk, acetylcholine applied to the same spot produces always an inhibition of the heart beats. Conversely, when the ganglion cells activated previously by acetylcholine, a subsequent administration of atropine suppresses the activity of the ganglion cells, resulting in an inhibition of the heart beats.</p