Kojiro Matsuda

Neurosecretory Cell: Capable of Conducting Impulse in Rats

Electriic vtinulation of the rat neurohypophlysis in Situ evoked the unit action potentials. in the supraoptic nucleus. Compound and unit action potentials. were recorded from the isolated neurohypophysis stimulation. The applicaition of solutions high in potassium or devoid of sodium made the neurohypophysis inexcitable. Mammalian neurosecretsecretory cells have the neuronal properties generation and conduction of action potentials.

Indices for the role played by regional flow resistance in blood pressure reflex

SummaryAn index, α = (Δr/r)/(ΔR/R), is proposed for assessment of the relative degree of participation of a regional flow resistance in a blood pressure reflex, wherer andR are regional and total peripheral resistances respectively and Δs refer to their reflexive changes. For actual computation, α =I (iΔP − PΔi)/i(IΔP − PΔI), whereI=cardiac output,i=regional flow rate,P=mean arterial pressure. When the change in cardiac output is neglegible, the above equation is simplified as Δ=1 − PΔi/iΔP. Another index,β = Δg/ΔG = (PΔi − iΔP)/(PΔI − IΔP), is introduced for the degree of contribution of a region to a reflex, whereg andG are regional and total conductances.αi = β1. Some examples of application of the indices are presented.

Membrane Potential of Toad Ventricle: Changes Produced by Vagal Stimulation and Acetylcholine

Reduction produced by vagal stimulation and application of acetylcholine in the duration of the membrane action potential in the toad is clearly demonstrated in the ventricular fiber as well as in the atrium. Vagal innervation of the ventricle is thus demonstrated. Vagal innervation of the ventricle is considered to be less extensive than vagal innervation of the atrium.