The ERG and the corneo-retinal standing potential of the eyes of various kinds of vertebrates such as Mammals (Rodentia), Ayes, Reptilia, Amphibia and Pisces were recorded by means of the direct amplifier-oscillograph (orpenwriter) system.
Comparative studies on the variations in the ERG and in the corneo-retinal standing potential of the eyes during light and dark adaptations were made using the above-mentioned animals.The existence of the c-wave on the ERG was confirmed clearly in all cases of the animals examined, although only a small amplitude of the c-wave could be observed in the case of the squirrel. The peak times of the c-wave in cases of Amphibia and Pisces are far longer than those of the other animals.The peak time of the c-wave as measured from the onset of adapting light is 3-5 seconds for Rodentia and Ayes, 10-20 seconds for Reptilia and 1.5-3 minutes for Amphibia and Pisces.
The light peaks of the corneo-retinal standing potentials appear respectively 5-13 minutes for Mammals (Rodentia), 3-5 minutes for Ayes and 5-13 minutes for Reptilia after the onset of the adapting light.On the other hand, their post-d peaks appear between 30 seconds and 1 minute for Rodentia, between 20 seconds and 1 minute for Ayes and between 30 seconds and 4 minutes for Reptilia after the cessation of the adapting light.The dark trough appears 7-15 minutes for Rodentia, 4-7 minutes for Ayes, 10-20 minutes for Reptilia, 10-20 minutes for Amphibia and 15-20 minutes for Pisces after the cessation of the adapting light.
Some periodic variations in the corneo-retinal standing potential of the eye were observed following the ordinal ERG-wave in the course of light and dark adaptation.It was concluded that there are two different groups in the from of adaptation.The one form is obtained from man-group, and the other from frog-group.The variations of the standing potential for Mammals, Ayes and Reptilia belong to the man-group, while those for Amphibia and Pisces belong to the frog-group.In the case of the man-group, the light peak could always be observed successively in the course of light adaptation, and also the post-d peak was found in the course of dark adaptation.But, in the case of the frog-group, the light peak and the post-d peak was never observed.

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With single FLashes from a xenon discharge tube the electroretinogram (ERG) and light-induced optic nerve responses were recorded in the albino rabbit.The experiments were carried out in a dark room.
1. The early receptor potential (ERP) in the rabbit consisted of a small positive potential followed by a large negative swing.The second phase of the ERP was succeeded by the a-wave with a latency which is as short as about 1.6msec.
2. The conventional “compound spike potential of the optic nerve”, when induced with flash light, contains 1) the late-on-wave which is present only on low illumination and 2) the early-on-wave on which rhythmic wavelets are superimposed.The threshold of the wavelets appeared to approximate that of the oscillatory potential in the ERG.With increase of stimulus intensity the latency of the early-on-wave tended to decrease, finally approaching the absolute minimum latency (about 11msec).
3. When the stimulus intensity was raised up to an level sufficient for producing an ERP of considerable size, a rapid potential with a latency of about 4.5-5.0msec, at a tentative estimate, was found to emerge preceding the earlyon- wave in the optic nerve potential.The new potential which may be called provisionally the short latency optic nerve potential (SLONP) was consistently recordable in the central and/or ventral area of the optic nerve, but scarcely detectable in the dorsal area.The amplitude of the SLONP was linearly related to the log of stimulus intensity in the dynamic range where the slope of amplitude vs log intensity is steepest.In this range the amplitude of the negative phase of the ERP was found to be proportional to stimulus intensity.
4. The SLONP, along with the subsequent optic nerve potentials, were abolished with both nerve blockaders (lidocaine and tetrodotoxin) in low concentrations on their application to the retina.During this time the ERG components including the ERP were little affected.
5. The foregoing results, coupled with other data inclusive of the findings obtained by the microelectrode experiments described in this study, indicate that the SLONP is the population response due to a short latency optic nerve discharge arising from particular optic nerve fibers, most of which leave the retina to pass through the contralateral optic nerve tract towards the brain.
6. Differences between the SLONP and the early-on-wave in latency, lightthreshold, density function, vulnerability to anoxia, all suggest that the two potentials are distinct components.
7. It was shown that there is some correlation between the amplitude of ERP and that of the SLONP.The functional significance of the SLONP was discussed.
8. The comparative studies of the SLONP and the b-wave, which were obtained with regard to density functions and other aspects, may indicate that the two events behave independently.
9. Picrotoxin in low concentration, when applied topically to the retina from the vitreous side, could give rise to enhancing effects on optic nerve potentials. The possibility was discussed that, in the retina, there might be a presynaptic inhibitory mechanism which can be depressed by picrotoxin.

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An ATPase preparation of cell membranes was obtained from pig thyroid gland and the effects of various thyroid-tropic substances on it were systematically studied in vitro. TSH had little effect in stimulating Na⁺, K⁺-activated ATPase even at very high concentrations. Physiologically active estrogens, 1715-estradiol, estriol and estrone, were found to stimulate the enzyme significantly even at extremely low concentrations. Progesterone was active only at high concentrations. Testosterone, cortisone, dexamethasone, iodide, iodotyrosines, iodothyronines and perchlorate were all without effect. Thiocyanate, thiourea, propylthiouracil and methylthiouracil were slightly, but consistently, effective in depressing the enzyme. It is likely that estrogens stimulate and goitrogens depress thyroidal iodide uptake by influencing directly the activity of thyroidal Nat, K⁺-activated ATPase.

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1. The thresholds of the sensory endings of single spindle, leaf-like and tendon receptors in the frog sartorius muscle were measured with pressure test stimulations applied at different periods after a conditioning antidromic stimulation.
2. The threshold for the first discharge from the spindle receptor excited by a threshold pressure stimulation decreased transiently at approximately 30 msecafter the absolute refractory period of 1.1-1.6 msec after an antidromic discharge, and increased at 60 msec, then returned to the normal level for 650 msec.
3. In fresh preparations, a recurrent discharge appeared at 30 msec after an antidromic discharge, without test stimulation.When the muscle was extended, the periods of the appearance of the recurrent discharge and of the transient decrease of the threshold shortened, and the recovery curves of the threshold closed to the normal level over all of its course.
4. The threshold for the second discharge from the spindle produced by a larger mechanical stimulation returned to normal for 40-60 msec after an antidromic discharge, during which no transient decrease was observed.
5. The leaf-like receptors responded with only one discharge to different strengths of the pressure stimulation.The thresholds, which were higher than those of the spindle, decreased linearly after the absolute refractory period of up to 20 msec, and returned to normal 150 msec after an antidromic discharge.
6. The recovery curve of the threshold of tendon receptors could be drawn only for 5 out of 18 receptors tested, and it was suggested that in the remaining receptors the antidromic discharge may not have propagated along all of the branches beyond a node in the vicinity of the sensory endings, at which the parent axon may have divided into four or more branches. The threshold returned to normal approximately 300 msec after the absolute refractoryperiod of from 2.2 to 4.5 msec, without any transient decreases during it course.

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1. Crude preparation of substance P (SP) from the brains of several species and bovine peripheral nerves (ventral and dorsal root, vagus in the neck) were analyzed by alumina column chromatography, paper electrophoresis and paper chromatography, its biological activity being assayed on four different isolated tissues;guinea-pig ileum, chicken rectal caecum, rat uterus and duodenum.
2. The presence in the nerve granules of SP itself and ZETLER'S satellite polypeptides of SP, his Fa- and Fc-peptide, was demonstrated.
3. It was proved that Fa-peptide is quite similar to or identical with bradykinin.
4. ZETLER'S CC1₄ treatment of the crude SP as well as LEMBECK's chloroformmethanol extraction was shown to cause an increase in Fa-peptide content.
5. Fa-peptide could be, as reported by LEMBECK and his co-workers, extracted by chloroform-methanol from the brain tissue, but its solubility in the organic solvent was found to be far less than that in water, about a half being easily transfered to water phase by mere washing, while a greater part of SP itself was left unextracted.Therefore it appears not so likely that SP and Fa-peptide bind with lipids in the nervous tissues.
6. When partially purified SP prepared from nerve granules by alumina column chromatography was incubated with trypsin, plasmin or kallikrein, SP itself was inactivated but a kinin-like component nearly identical with Fa-peptide was newly formed.A precursor or precursors in nerve granules of such a kinin-like substance were shown to be easily released with SP itself by laking the granules in neutral hypotonic solutions.
7. Leaving aside the question as to whether or not it is naturally-occurring, therefore, Fa-peptide pre-existing in the neuronal SP preparation can probably be considered to be formed by a kinin forming enzyme or enzymes and protein denaturation.

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1. Applying the method of ROCHA E SILVA for purification of bradykinin, partial purification of the active substance in ZETLER'S Fa-fraction from the crude brain SP has been attempted.
2. The active substance was concentrated to about 50 times as active as the crude preparation, the partially purified active polypeptide was found to be quite similar to bradykinin in the pharmacological and chemical properties.
3. Brain homogenates of rabbits have been investigated for the presence of kinin-forming and-destroying activities.
4. Kinin-forming activity was chiefly detected in the microsomal fraction and it appears to be attributable to the presence of a kallikrein-like enzyme or enzymes.
5. Kininase activity was present in all the subcellular fractions of rabbit brain, the highest in the soluble fraction. But considerable activity was firmly bound with cytoplasmic granules and appears not to originate from intracellular cathepsins.

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1. Experiments were carried out on 25 adult cats under spinal transection at the C₁ level in order to extend observations on the chloralose jerky muscular contraction and to analyze the effects of chloralose on spinal reflexes.
2. Chloralose (25-35mg/kg) was administered intravenously to spinal cats. These cats did not exhibit generalized jerky muscular reactions, even when a large dosage of 100mg/kg was administered.Blood pressure and heart rate were not changed by chloralose anesthesia at a dosage level lower than 45mg/kg. The following results were observed: 1) Slight augmentation of the monosynaptic reflex response, with a reduction in amplitude of polysynaptic reflex responses. 2) Reduction of the inhibitory influence of the sural nerve on the extensor monosynaptic reflex response. 3) Reduction of the Renshaw cell recurrent inhibition to the motoneurons. 4) Reduction of potential from the cord dorsum (N₂ and P), dorsal root, and dorsal root reflex responses. 5) Reduction of augmentation of antidromic potentials of the primary afferent fibers following sural nerves timulation. 6) Reduction of the interlimb reflex response and augmentation of the local lumbosacral monosynaptic reflex response to the forelimb nerve stimulation, without alteration of the initial diminution.
3. The observations suggest that the chloralose has a depressing action on the spinal polysynaptic reflex process and/or interneurons. Neural mechanisms of the chloralose jerky muscular contraction could not be due to mechanisms in the spinal cord.

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