Distinct developmental principles underlie the formation of ipsilateral and contralateral whisker-related axonal patterns of layer 2/3 neurons in the barrel cortex.

Axonal organizations with specific patterns underlie the functioning of local intracortical circuitry, but their precise anatomy and development still remain elusive. Here, we selectively visualized layer 2/3 neurons using in utero electroporation and examined their axonal organization in the barrel cortex contralateral to the electroporated side. We found that callosal axons run preferentially in septal regions of layer 4 and showed a whisker-related pattern in the contralateral barrel cortex in rats and mice. In addition, presynaptic marker proteins were found in this whisker-related axonal organization. Although the whisker-related patterns were observed in both the ipsilateral and contralateral barrel cortex, we found a difference in their developmental processes. While the formation of the whisker-related pattern in the ipsilateral cortex consisted of two distinct steps, that in the contralateral cortex did not have the 1st step, in which the axons were diffusely distributed without preference to septal or barrel regions. We also found that these more diffuse axons ran close to radial glial fibers. Together, our results uncovered a whisker-related axonal pattern of callosal axons and two independent developmental processes involved in the formation of the axonal trajectories of layer 2/3 neurons.

Determination of glutathione peroxidase activity and its contribution to hydrogen peroxide removal in erythrocytes.

A new method for the determination of glutathione peroxidase activity in erythrocytes was developed. The present method was applied to the measurement of hydrogen peroxide removal rates by glutathione peroxidase in erythrocytes at 70 microM hydrogen peroxide under simulated in vivo conditions. The removal rates by glutathione peroxidase in mouse erythrocytes were twenty-times faster than those in human ones and were 5.2 mumol/sec/g of Hb. The removal rates in acatalasemic mouse erythrocytes indicate that glutathione peroxidase is the main means of hydrogen peroxide removal in acatalasemic mouse erythrocytes. Based on these results, we concluded that glutathione peroxidase in mouse erythrocytes had sufficient ability to remove hydrogen peroxide at even relatively high concentrations. This may be one of the reasons why acatalasemic mice suffer no health problems while Japanese acatalasemic patients suffer from Takahara disease when infected with hydrogen peroxide-generating bacteria.

Characterization of hydrogen peroxide removal activities in mouse hemolysates: catalase activity and hydrogen peroxide removal activity by hemoglobin.

Hydrogen peroxide removal activities in normal and acatalasemic mouse hemolysates were examined to determine the optimal temperature of catalase. From thermal stability of the removal activities in hemolysates, the removal activities were divided into two activities. The removal activity deactivated at lower temperature was catalase, and the 50% inactivation was observed after 10 min incubation at 47.2 +/- 0.5 degrees C for normal hemolysates and 34.0 +/- 0.8 degrees C for acatalasemic ones. The removal activity deactivated at a higher temperature remained after the addition of sodium azide, and the 50% inactivation was observed at 63.5 +/- 1.4 degrees C. After separation of the removal activities by carboxymethyl-cellulose column chromatography, the removal activity deactivated at higher temperature was attributed to the activity by hemoglobin. From Lineweaver-Burk plot analysis of the removal rates by hemoglobin at 37 degrees C, the Michaelis constant for hydrogen peroxide and the maximum velocity were 201 +/- 53 microM and 5.37 +/- 1.39 micromol/s per g of Hb, respectively. Removal rates by hemoglobin in mouse hemolysates at 37 degrees C in 70 microM hydrogen peroxide were 1.32 +/- 0.12 micromol/s per g of Hb. Catalase activity (k/g Hb: rate constant related to the hemoglobin content) in normal mouse hemolysates was 104 +/- 12 at 25 degrees C and 117 +/- 10 at 37 degrees C, and that in acatalasemic hemolysates was 10.5 +/- 1.7 at 25 degrees C. These results indicate that activity of hydrogen peroxide removal by hemoglobin is substantial and the activity in acatalasemic hemolysates is predominant at low concentration of hydrogen peroxide.

Spectrophotometric determination of hydrogen peroxide: catalase activity and rates of hydrogen peroxide removal by erythrocytes.

A new method of hydrogen peroxide determination for the measurement of catalase activity and rates of hydrogen peroxide removal by erythrocytes was described. Hydrogen peroxide was determined by converting it to the indamine dye with a water-soluble ironporphyrin and measuring the absorbance at 590 nm. This method was applied to the assay of catalase in hemolysates from human, rat and mouse blood. The activities obtained were in agreement with those obtained by other methods including UV method. The present method was also applied to the determination of rates of hydrogen peroxide removal by intact erythrocytes from human subjects, rats and mice. Data suggested that normal erythrocytes have substantial capacity to remove extracellular hydrogen peroxide. From the measurement of catalase activity in erythrocytes treated with 3-amino-1,2,4-triazole and rates of hydrogen peroxide removal by the erythrocytes, it is deduced that rate constants related to the hemoglobin content (k/g Hb) for hydrogen peroxide removal by catalase in normal and acatalasemic erythrocytes are 42.0 +/- 6.0 and 8.0 +/- 3.0, respectively.

Immunohistochemical investigations of parvalbumin localization in the skeletal muscle fibers of rats.

Parvalbumin (PA) is a water soluble, low-molecular weight, calcium-binding protein which has been thought to be involved in the relaxation of skeletal muscle fibers. Although it is well known that PA concentrations are higher in fast twitch fiber than slow twitch fiber, the localization of PA within the cytoplasm of single muscle fibers is still unknown. The present study, therefore, was undertaken to clarify the PA localization by immunohistochemical methods using the confocal laser scanning microscope (CLSM) and transmission electron microscope (TEM). Wistar strain male rats were fixed by vascular perfusion with 4% paraformaldehyde solution, and the extensor digitorm longus muscle was dissected out. For fluorescent antibody examination, these specimens were quickly frozen in melting isopentan and sections were cut using a cryostat at -25 degrees C. These sections were incubated in anti-PA and anti-Troponin (TR) respectively, and then exposed to Texas-Red- and FITC-labelled secondary antibodies. For TEM study, the pre-embedding method was used. Fluorescent immunohistochemical study has clearly shown that both PA and TR are located intimately in the I-band of the skeletal muscle fibers. The finding by the immunofluorescent study correlated well with those which have been seen at the ultrastructural level. The fact that PA is located in close proximity to TR is considered to be very reasonable when we consider it in terms of the muscular contraction-relaxation cycle.

High-performance liquid chromatographic determination of taurine and hypotaurine using 3,5-dinitrobenzoyl chloride as derivatizing reagent.

A method for the determination of taurine and hypotaurine in biological samples involving the preparation of their 3,5-dinitrobenzoyl derivatives followed by HPLC was established. Taurine and hypotaurine in aqueous media were reacted with 3,5-dinitrobenzoyl chloride in the presence of triethylamine to prepare 3,5-dinitrobenzoyl derivatives. These derivatives were separated on a C18 reversed-phase column and detected by recording the absorbance at 254 nm. Derivatives of taurine and hypotaurine were obtained in yields of 91.4 +/- 3.3 and 85.6 +/- 2.6%, respectively. The calibration graphs for taurine and hypotaurine were linear between 2.5 and 500 microM with correlation coefficients of 0.999. The method was applied to the determination of taurine and hypotaurine in human and rat urine and blood and in rat liver and heart.

Three-dimensional structures of the neck region of the hamster spermatozoa in the caudal epididymis.

Three-dimensional structures of the capitulum and first mitochondria in the neck region of the hamster spermatozoa, were observed with transmission (TEM) and scanning electron microscope (SEM). Some capitula revealed a variable contour even in the caudal epididymis, but most finally developed to form a typical wagonette shape. The final shape of the capitulum is probably produced by the aid of apical protrusion of the right, pyramidal mitochondrium. The right and left first mitochondria were triangular pyramids in contour, while the dorsal and ventral ones were rod-like in shape. The mutual transformations between the capitulum and the first mitochondria are discussed in relation to the completion of the neck region.

Scanning electron microscopic observations of the arachnoid granulations in monkeys with cerebrospinal fluid hypotension.

The changes in arachnoid granulations following the depletion of cerebrospinal fluid (CSF) were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the normal tissue, the arachnoid granulations located at the inner walls of the superior sagittal sinus and the straight sinus had bulging protrusions of various sizes, as viewed with the SEM. With TEM, the outermost cells covering the surface of the arachnoid granulations had "giant vacuoles" in the cytoplasm. With CSF hypotension, the arachnoid granulations were smaller in size and the outermost layer of cells were thinner. The vacuoles in the outer layer were not developed. In the apical region of the individual arachnoid granulations with CSF hypotension, the arachnoid cells were densely clustered under the endothelial cells. With recovery to normal CSF pressure, the arachnoid cells appeared to protrude between the endothelial cells covering the apical portion of the arachnoid granulation.

Modular invariant representations of infinite-dimensional Lie algebras and superalgebras.

In this paper, we launch a program to describe and classify modular invariant representations of infinite-dimensional Lie algebras and superalgebras. We prove a character formula for a large class of highest weight representations L(lambda) of a Kac-Moody algebra [unk] with a symmetrizable Cartan matrix, generalizing the Weyl-Kac character formula [Kac, V. G. (1974) Funct. Anal. Appl. 8, 68-70]. In the case of an affine [unk], this class includes modular invariant representations of arbitrary rational level m = t/u, where t [unk] Z and u [unk] N are relatively prime and m + g >/= g/u (g is the dual Coxeter number). We write the characters of these representations in terms of theta functions and calculate their asymptotics, generalizing the results of Kac and Peterson [Kac, V. G. & Peterson, D. H. (1984) Adv. Math. 53, 125-264] and of Kac and Wakimoto [Kac, V. G. & Wakimoto, M. (1988) Adv. Math. 70, 156-234] for the u = 1 (integrable) case. We work out in detail the case [unk] = A(1) ((1)), in particular classifying all its modular invariant representations. Furthermore, we show that the modular invariant representations of the Virasoro algebra Vir are precisely the "minimal series" of Belavin et al. [Belavin, A. A., Polyakov, A. M. & Zamolodchikov, A. B. (1984) Nucl. Phys. B 241, 333-380] using the character formulas of Feigin and Fuchs [Feigin, B. L. & Fuchs, D. B. (1984) Lect. Notes Math. 1060, 230-245]. We show that tensoring the basic representation and modular invariant representations of A(1) ((1)) produces all modular invariant representations of Vir generalizing the results of Goddard et al. [Goddard P., Kent, A. & Olive, D. (1986) Commun. Math. Phys. 103, 105-119] and of Kac and Wakimoto [Kac, V. G. & Wakimoto, M. (1986) Lect. Notes Phys. 261, 345-371] in the unitary case. We study the general branching functions as well. All these results are generalized to the Kac-Moody superalgebras introduced by Kac [Kac, V. G. (1978) Adv. Math. 30, 85-136] and to N = 1 super Virasoro algebras. We work out in detail the case of the superalgebra B(0, 1)((1)), showing, in particular, that restricting to its even part produces again all modular invariant representations of Vir. These results lead to general conjectures about asymptotic behavior of positive energy representations and classification of modular invariant representations.