Morphological characterization of the bursting and nonbursting neurones in the olfactory centre of the terrestrial slug limax marginatus

We investigated the morphological characteristics of physiologically characterized neurones in the procerebrum (PC) of the terrestrial slug Limax marginatus. The electrophysiological characteristics of the neurones were determined using the perforated patch recording technique. By comparing the shapes and sizes of somata, we found that the somata of bursting neurones were larger and had more oblong shapes than those of nonbursting neurones, indicating that the bursting and nonbursting neurones in the PC could be discriminated on the basis of the sizes and shapes of their soma. Injection of fluorescent dyes into the bursting and nonbursting neurones revealed morphological differences in the neurites. The bursting neurones had extensive projections within the cell body layer, and the major neurites of the bursting neurones were oriented along the dorsal-ventral axis. In contrast, the nonbursting neurones had neurites extending into the neuropile layers, where terminals of both sensory and presumed output neurones exist

Comparative study on neural oscillation in the procerebrum of the terrestrial slugs Incilaria bilineata and

Coherent oscillatory activities in procerebral neurones have been described in Limax maximus; however, the electrical properties of the procerebrum of other terrestrial molluscs are less well understood. We have examined oscillatory activity in the procerebrum of Incilaria bilineata and Limax marginatus. The local field potential measured in the procerebrum of I. bilineata showed repetitive peaks which had the opposite polarity from those measured in L. marginatus. Optical measurement of membrane potential using a potential-sensitive dye, di-4-ANEPPS, showed that the oscillations in I. bilineata occurred mainly in the internal mass while those in L. marginatus were located in the cell mass. An analysis of the waveform revealed that the depolarizing phase of the oscillations consists of both a slow and a rapid component in both species. The rapid component was most pronounced in the internal mass of I. bilineata but was prominent in the cell mass of L. marginatus. The superior tentacle nerve, which projects to the terminal mass, also showed oscillations in synchrony with those of the procerebrum. These results suggest that oscillations in procerebral interneurones are commonly generated in a region adjacent to the terminal mass and that these oscillations may affect the membrane potential of the neurones constituting the superior tentacle nerve

A Novel Method for Detecting Lanthanum Phosphate Deposition in the Gastroduodenal Mucosa Using Fluorescence Microscopy

Diagnostic utility of fluorescence microscopy for lanthanum phosphate deposition in the gastrointestinal mucosa has not been reported previously. In this study, we comparatively assessed the light, electron, and fluorescence microscopy features of gastroduodenal lanthanum phosphate deposition in 10 patients with deposits in the stomach and 5 patients with deposits in the duodenum. During light microscopy, lanthanum deposits were observed as dark-brown, needle-shaped, or crystalloid structures and pale red amorphous materials. During electron microscopy, the deposited material appeared as bright aggregates. Fluorescence microscopy also revealed lanthanum deposits as bright areas under green, red, and blue filters. The deposits were more easily recognizable on electron and fluorescence microscopy than on light microscopy. Furthermore, during fluorescence microscopy, the green filter provided the most clear visualization of lanthanum phosphate. In conclusion, fluorescence microscopy with a green filter is useful in determining the degree and extent of lanthanum deposition in the gastroduodenal mucosa

N-methyl-D-aspartate receptors play important roles in acquisition and expression of the eyeblink conditioned response in glutamate receptor subunit delta2 mutant mice.

Classical eyeblink conditioning has been known to depend critically on the cerebellum. Apparently consistent with this, glutamate receptor subunit delta2 null mutant mice, which have serious morphological and functional deficiencies in the cerebellar cortex, are severely impaired in delay paradigm. However, these mutant mice successfully learn in trace paradigm, even in \u270-trace paradigm,\u27 in which the unconditioned stimulus starts just after the conditioned stimulus terminates. Our previous studies revealed that the hippocampus and the muscarinic acetylcholine receptors play crucial roles in 0-trace paradigm in glutamate receptor subunit delta2 null mutant mice unlike in wild-type mice, suggesting a large contribution of the forebrain to 0-trace conditioning in this type of mutant mice. In the present study, we investigated the role of N-methyl-D-aspartate receptors in 0-trace eyeblink conditioning in glutamate receptor subunit delta2 null mutant mice. Mice were injected intraperitoneally with the noncompetitive N-methyl-d-aspartate receptor antagonist (+)MK-801 (0.1mg/kg) or saline, and conditioned with 350-ms tone conditioned stimulus followed by 100-ms periorbital shock unconditioned stimulus. Glutamate receptor subunit delta2 null mutant mice that received (+)MK-801 injection exhibited a severe impairment in acquisition of the conditioned response, compared with the saline-injected glutamate receptor subunit delta2 null mutant mice. In contrast, wild-type mice were not impaired in acquisition of 0-trace conditioned response by (+)MK-801 injection. After the injection solution was changed from (+)MK-801 to saline, glutamate receptor subunit delta2 null mutant mice showed a rapid and partial recovery of performance of the conditioned response. On the other hand, when the injection solution was changed from saline to (+)MK-801, glutamate receptor subunit delta2 null mutant mice showed a marked impairment in expression of the pre-acquired conditioned response, whereas impairment of the expression was small in wild-type mice. Injection of (+)MK-801 had no significant effects on spontaneous eyeblink frequency or startle eyeblink frequency to the tone conditioned stimulus in either glutamate receptor subunit delta2 null mutant mice or wild-type mice. These results suggest that N-methyl-D-aspartate receptors play critical roles both in acquisition and expression of the conditioned response in 0-trace eyeblink conditioning in glutamate receptor subunit delta2 null mutant mice

The hippocampus plays an important role in eyeblink conditioning with a short trace interval in glutamate receptor subunit delta 2 mutant mice.

Mutant mice lacking the glutamate receptor subunit delta2 exhibit changes in the structure and function of the cerebellar cortex. The most prominent functional feature is a deficiency in the long-term depression (LTD) at parallel fiber-Purkinje cell synapses. These mutant mice exhibit severe impairment during delay eyeblink conditioning but learn normally during trace eyeblink conditioning without the cerebellar LTD, even with a 0 trace interval. We investigated the hippocampal contribution to this cerebellar LTD-independent "0 trace interval" learning. The mutant mice whose dorsal hippocampi were aspirated exhibited severe impairment in learning, whereas those that received post-training hippocampal lesions retained the memory. The wild-type mice showed no impairment in either case. These results suggest that the hippocampal component of the eyeblink conditioning task becomes dominant when cerebellar LTD is impaired

Proton Magnetic Resonance Spectroscopy in Patients with Migration Disorders

Proton Magnetic Resonance Spectroscopy (1H-MRS) can be used to detect cerebral metabolites including N-acetylaspartate (NAA)，creatine (Cr) and choline (Ch). Hence，clinical applications of this method for neuropediatric diseases can be expected. However，regarding neuronal migration disorders，there have been only a few reported studies. We therefore examined the lH-MRS in six patients with migration disorders，ages ranged from 8months to 28years 10months with a mean of 10years 10months. Investigation was performed using Magnetom H15 (Siemens) with a repetition time of 1500 msec and an echo time of 270msec. The ratio of NAA/Cr，Ch/Cr were examined. The volume of interest with the size of 2 × 2 × 2 ～ 3 × 3 × 5cm3 was chosen in the area including lesions，and a contralateral area without lesions was also investigated. Results were as follows. 1) The ratio of NAA/Cr was low in the area with lesions in all 6cases; 1.41，1.95，2.27 and 1.71 in cases with heterotopic gray matter，0.99 in one case with polymicrogyria，an d 1.30 in one case with hemimegalencephaly，contrasted with a contralataral area without lesions: 1.89， 2.89，2.87，2.55，3.26，2.03，respectively. 2) The ratio of Ch/Cr showed no consistent difference between the area including lesions and contralataral area without lesions. Our findings of a decreased NAA/Cr ratio can be inferred to reflect the decreased numbers of neuronal cell population，or reduced metabolism in the lesions

Study of laser frequency stability from the observed vertical wind velocity by the Na lidar at Troms*

The Tenth Symposium on Polar Science/Ordinary sessions: [OS] Space and upper atmospheric sciences, Wed. 4 Dec. /Entrance Hall (1st floor) at National Institute of Polar Research (NIPR

Naturally Occurring 3RS, 7R, 11R-Phytanic Acid Suppresses In Vitro T-Cell Production of Interferon-Gamma

Background: Among the eight stereoisomers of phytanic acid (PA), the 3RS, 7R, 11R-isomer is naturally occurring and is present in foods and the human body. PA is considered to have possible health benefits in the immune system. However, it remains undetermined whether these effects are elicited by the 3RS, 7R, 11R-PA isomer, because previous studies used a commercially available PA whose isomer configuration is unknown. In this study, we synthesized a preparation of 3RS, 7R, 11R-PA, and investigated its in vitro immunomodulatory effects, especially the T-cell production of interferon (IFN)-γ, which is associated with various autoimmune diseases. This study also investigated the effects of 3RS, 7R, 11R-PA on NF-κB activity in order to address the mechanism of its immunomodulatory effects. Methods: Mouse splenocytes and purified T-cells were stimulated with T-cell mitogens and incubated with 3RS, 7R, 11R-PA, followed by evaluation of IFN-γ production. The effect of 3RS, 7R, 11R-PA on NF-κB activity was also investigated using an A549 cell line with stable expression of an NF-κB-dependent luciferase reporter gene. Results: 3RS, 7R, 11R-PA significantly reduced in vitro IFN-γ production at both the protein and mRNA levels, and was accompanied by decreased expression of T-bet, a key regulator of Th1 cell differentiation. The results indicated that NFκB-mediated transcriptional activity was significantly decreased by 3RS, 7R, 11R-PA and that GW6471, an antagonist of peroxisome proliferator activated receptor α (PPARα), abrogated the inhibitory effect of 3RS, 7R, 11R-PA on NF-κB activity. Conclusions: The present study suggests that 3RS, 7R, 11R-PA is a functional and bioactive fatty acid, and has a potentially beneficial effect for amelioration of T-cell mediated autoimmune diseases. This study also indicates that interference in the NF-κB pathway via PPARα activation is a potential mechanism of the immunomodulatory effects of 3RS, 7R, 11R-PA

Changes in Expression of the Autophagy-Related Genes Microtubule-Associated Protein 1 Light Chain 3β and Autophagy Related 7 in Skeletal Muscle of Fattening Japanese Black Cattle: A Pilot Study

Objective Autophagy is a bulk degradation system for intracellular proteins which contributes to skeletal muscle homeostasis, according to previous studies in humans and rodents. However, there is a lack of information on the physiological role of autophagy in the skeletal muscle of meat animals. This study was planned as a pilot study to investigate changes in expression of two major autophagy-related genes, microtubule-associated protein 1 light chain 3β (MAP1LC3B) and autophagy related 7 (ATG7) in fattening beef cattle, and to compare them with skeletal muscle growth. Methods Six castrated Japanese Black cattle (initial body weight: 503±20 kg) were enrolled in this study and fattened for 7 months. Three skeletal muscles, M. longissimus, M. gluteus medius, and M. semimembranosus, were collected by needle biopsy three times during the observation period, and mRNA levels of MAP1LC3B and ATG7 were determined by quantitative reverse-transcription polymerase chain reaction. The expression levels of genes associated with the ubiquitin-proteasome system, another proteolytic mechanism, were also analyzed for comparison with autophagy-related genes. In addition, ultrasonic scanning was repeatedly performed to measure M. longissimus area as an index of muscle growth. Results Our results showed that both MAP1LC3B and ATG7 expression increased over the observation period in all three skeletal muscles. Interestingly, the increase in expression of these two genes in M. longissimus was highly correlated with ultrasonic M. longissimus area and body weight. On the other hand, the expression of genes associated with the ubiquitin-proteasome system was unchanged during the same period. Conclusion These findings suggest that autophagy plays an important role in the growth of skeletal muscle of fattening beef cattle and imply that autophagic activity affects meat productivity