A systematic analysis of neurons with large somatosensory receptive fields covering multiple body regions in the secondary somatosensory area of macaque monkeys.

Previous neurophysiological studies performed in macaque monkeys have revealed complex somatosensory responses in the secondary somatosensory area (SII), such as large receptive fields (RFs), as well as bilateral ones. However, systematic analyses of neurons with large RFs have not been performed. In the present study, we recorded single-unit activities in SII of awake macaque monkeys to investigate systematically large RFs by dividing the whole body into four body regions (head, trunk, forelimb, and hindlimb). Recorded neurons were classified into two types, according to whether the RFs were confined to one body region: single (n = 817) and combined (n = 282) body-region types. These two types were distinct in terms of the percentage of bilateral RFs: 55% in the single-region type and 90% in the combined type, demonstrating that two types of RF enlargement occur simultaneously in the combined type, namely, RF convergence from different body regions and RF convergence from both hemibodies. Among the combined-type RFs, two tendencies of RF convergence were found: 1) the distal parts of the limbs (i.e., hand and foot) and the mouth are interconnected, and 2) the trunk RFs extend continuously toward the distal parts of the limb and head to cover the entire body surface. Our distribution analysis on unfolded maps clarified that neurons having RFs with these two tendencies were distributed within specific subregions in SII.

Pharmacological properties of AC-3933, a novel benzodiazepine receptor partial inverse agonist.

We investigated in this study the pharmacological properties of AC-3933 (5-(3-methoxyphenyl)-3-(5-methyl-1,2,4-oxadiazol-3-yl)-1,6-naphthyridin-2(1H)-one), a novel benzodiazepine receptor (BzR) partial inverse agonist. AC-3933 potently inhibited [3H]-flumazenil binding to rat whole brain membrane with a Ki value of 5.15 ± 0.39 nM and a GABA ratio of 0.84 ± 0.03. AC-3933 exhibited almost no affinity for the other receptors, transporters and ion channels used in this study. In addition, AC-3933, in the presence of GABA (1 µM), gradually but significantly increased [³5S] tert-butylbicyclophosphorothionate binding to rat cortical membrane to 117.1% of the control (maximum increase ratio) at 3000 nM. However, this increase reached a plateau at 30 nM with hardly any change at a concentration range of 100-3000 nM (from 115.2% to 117.1%). AC-3933 (0.1-10 µM) significantly enhanced KCl-evoked acetylcholine (ACh) release from rat hippocampal slices in a concentration-dependent manner. Moreover, in vivo brain microdialysis showed that intragastric administration of AC-3933 at the dose of 10 mg/kg significantly increased extracellular ACh levels in the hippocampus of freely moving rats (area under the curve (AUC0₋2 h) of ACh level; 288.3% of baseline). These results indicate that AC-3933, a potent and selective BzR inverse agonist with low intrinsic activity, might be useful in the treatment of cognitive disorders associated with degeneration of the cholinergic system.

Follicular dendritic cell-secreted protein is decreased in experimental periodontitis concurrently with the increase of interleukin-17 expression and the Rankl/Opg mRNA ratio.

BACKGROUND AND OBJECTIVE: T-helper type 17 (Th17) cells produce interleukin-17 (IL-17) and help to protect against inflammation and infection in periodontal disease. Furthermore, while follicular dendritic cell-secreted protein (FDC-SP) may be involved in the inflammation of periodontal tissue, the biological role of FDP-SP in periodontal disease is still unknown. The purpose of the present study was to clarify the expression of IL-17 and FDC-SP in experimental periodontitis in rats. MATERIAL AND METHODS: Seven-week-old male Wistar rats were divided into baseline control, sham and test groups. Experimental periodontitis was induced by placing a ligature in the mesiopalatal area, and untreated rats served as a baseline control group. Morphological changes in alveolar bone were investigated 7, 14 and 28 d after treatment. Expression of the Rankl, osteoprotegerin (Opg) and Il17 genes was analyzed 5 and 7 d after the induction of experimental periodontitis. RESULTS: Alveolar bone resorption progressed in the test group for 7 d, but not thereafter. At 5 d after the induction of periodontitis, the Rankl/Opg mRNA ratio and the expression of IL-17 in the test group were significantly increased compared with the respective values in the baseline control group; however, there were no significant differences between the test and control groups at 7 d. The expression of FDC-SP was significantly decreased in the test group compared with the baseline control group at 5 and 7 d after the induction of periodontitis, and this value had returned to normal levels at 14 and 28 d. CONCLUSION: These results suggest that both IL-17 and FDC-SP could be involved in the inflammatory response, and FDC-SP in the junctional epithelium might play an important role in the Th17 cell-related immune response.

Antimicrobial photodynamic therapy using a diode laser with a potential new photosensitizer, indocyanine green-loaded nanospheres, may be effective for the clearance of Porphyromonas gingivalis.

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) is a new treatment method for the removal of infectious pathogens using a photosensitizer and light of a specific wavelength, e.g., toluidine blue with a wavelength of about 600 nm. We explored a new photosensitizer and focused on indocyanine green (ICG), which has high absorption at a wavelength of 800-805 nm. We investigated the bactericidal effect of PDT on Porphyromonas gingivalis using a new photosensitizer, ICG-loaded nanospheres with an 805 nm wavelength low-level diode laser irradiation. METHODS: We designed ICG-loaded nanospheres coated with chitosan (ICG-Nano/c) as a photosensitizer. A solution containing Porphyromonas gingivalis (10(8)  CFU/mL) with or without ICG-Nano/c (or ICG) was prepared and irradiated with a diode laser or without laser irradiation as a negative control. The irradiation settings were 0.5 W with a duty ratio of 10%, for 3-100 ms in repeated pulse (RPT) or continuous wave mode. CFU were counted after 7 d of anaerobic culture. RESULTS: We observed that ICG-Nano/c could adhere to the surface of P. gingivalis. When ICG-Nano/c was used for aPDT, irradiation with RPT 100 ms mode gave the lowest increase in temperature. Laser irradiation with ICG-Nano/c significantly reduced the number of P. gingivalis (i.e., approximately 2-log10 bacterial killing). The greatest bactericidal effect was found in the RPT 100 ms group. However, laser irradiation (RPT 100 ms) with ICG, as well as without photosensitizer, had no effect on the number of bacteria. CONCLUSIONS: Within the limits of this study, ICG-Nano/c with low-level diode laser (0.5 W; 805 nm) irradiation showed an aPDT-like effect, which might be useful for a potential photodynamic periodontal therapy.

Two cases of left-sided gastroschisis: review of the literature.

In gastroschisis, the opening is almost always to the right of the umbilicus, although eight cases of left-sided gastroschisis have been reported in the literature. We encountered two additional cases of left-sided gastroschisis. One was treated successfully, but the another child died. We report the present two these two cases and a review of the literature.

Processing of tactile and kinesthetic signals from bilateral sides of the body in the postcentral gyrus of awake monkeys.

Earlier studies pointed out that in the primary somatosensory cortex (SI) the receptive fields (RF) of bilateral neurons were related exclusively to the body midline. We recently found a substantial number of neurons with bilateral RFs on hand digits, shoulders/arms or legs/feet in the caudalmost part (areas 2 and 5) of the postcentral gyrus in awake macaque monkeys. The RFs of these neurons were generally of the most complex types found in this region of the cortex, and thus they were considered to be at the highest level along the hierarchical chain of information processing. We conclude that there are two types of bilateral RFs in the postcentral gyrus, one representing the midline structures such as the intraoral cavity, chin or trunk and the other related to limb structures such as fingers, hands, arms, shoulders, legs and girdles. Functional significance of the bilateral activity could be understood in behavioral context as it is seen more extensively in the body parts where bilateral coordination is essential.

Bilateral activity and callosal connections in the somatosensory cortex.

Earlier studies recording single neuronal activity in the postcentral somatosensory cortex of monkeys converged in suggesting that the bilateral receptive fields were related exclusively to the body midline including the trunk, perioral face, and oral cavity. These neurons were recorded mostly in the rostral part of the gyrus, areas 3b and 1. However, the authors recently found a substantial number of neurons with bilateral receptive fields on extremities, hand/digits, shoulders/arms, or legs/feet in the caudalmost part (areas 2 and 5) of the postcentral gyrus. The authors review these results and discuss functional implications of the bilateral representation in the postcentral somatosensory cortex.

Gastric pneumatosis associated with duodenal stenosis and malrotation.

Pneumatosis intestinalis, which is linear or cystic gas within the bowel wall, is usually found in premature babies in association with necrotizing enterocolitis. Gastric pneumatosis defined as intramural gas of the stomach is a rare sign during infancy. We report an infant with Down's syndrome and a duodenal web with obvious gastric pneumatosis.

Horizontal and vertical transmission of mouse class I MHC sequence in Schistosoma mansoni.

The mouse major histocompatibility complex (MHC) class I sequence was detected in 8-week-old Schistosoma mansoni by in situ polymerase chain reaction (in situ PCR). The signals to the mouse class I MHC sequence were observed in the nuclei of the mesenchymal and reproductive cells of S. mansoni. Signals were also observed in the cytoplasm of the tegumental tubercles. This finding suggested the possibility of MHC gene transfer from the host to schistosomes. Furthermore, the class I MHC sequence was detected in the DNA extracted from the cercariae of S. mansoni by nested PCR. Neither the nucleotide sequence of class I MHC detected in adult worm DNA nor that of class I MHC detected in the host (mouse) DNA was identical with that of class I MHC detected in the cercarial DNA. From the data we assumed that S. mansoni may have retained their own mouse class I MHC sequence in their genome throughout their life-cycle.

Self-images in the video monitor coded by monkey intraparietal neurons.

When playing a video game, or using a teleoperator system, we feel our self-image projected into the video monitor as a part of or an extension of ourselves. Here we show that such a self image is coded by bimodal (somatosensory and visual) neurons in the monkey intraparietal cortex, which have visual receptive fields (RFs) encompassing their somatosensory RFs. We earlier showed these neurons to code the schema of the hand which can be altered in accordance with psychological modification of the body image; that is, when the monkey used a rake as a tool to extend its reach, the visual RFs of these neurons elongated along the axis of the tool, as if the monkey's self image extended to the end of the tool. In the present experiment, we trained monkeys to recognize their image in a video monitor (despite the earlier general belief that monkeys are not capable of doing so), and demonstrated that the visual RF of these bimodal neurons was now projected onto the video screen so as to code the image of the hand as an extension of the self. Further, the coding of the imaged hand could intentionally be altered to match the image artificially modified in the monitor.

Cervical intradural disc herniation.

STUDY DESIGN: A case report of anterior en bloc resected cervical intradural disc herniation and a review of the literature. OBJECTIVE: To discuss the pathogenesis of cervical intradural disc herniation. SUMMARY OF BACKGROUND DATA: Including this study case, only 17 cases of cervical intradural disc herniation have been reported. There have been few detailed reports concerning the pathogenesis of cervical intradural disc herniation. METHODS: A cervical intradural disc herniation at C6-C7, with localized hypertrophy and segmentally ossified posterior longitudinal ligament, is reported in a 45-year-old man who had Brown-Sequard syndrome diagnosed on neurologic examination. Neuroradiologic, operative, and histologic findings, particularly the pathology of the anterior en bloc resected posterior vertebral portion of C6 and C7, were evaluated for discussion of the pathogenesis. RESULTS: Adhesion of dura mater and hypertrophic posterior longitudinal ligament was observed around a perforated portion of the herniated disc, and histologic study showed irregularity in fiber alignment accompanied by scattered inflammatory cell infiltration and hypertrophy in the posterior longitudinal ligament. The cervical intradural disc herniation was removed successfully and followed by C5-Th1 anterior interbody fusion with fibular strut graft. Neurologic recovery was complete except for minor residual sensory disturbance in the leg 7 years after the surgery. CONCLUSIONS: Cervical intradural disc herniation is an extremely rare condition. The pathogenesis remains obscure. Only 16 cases have been reported in the literature, and there has been little discussion concerning the local pathology of the herniated portion. The pathogenesis of the disease in the patient reported here was considered to be the adhesion and fragility of dura mater and posterior longitudinal ligament. This was caused by hypertrophy, with chronic inflammation and ossification of the posterior longitudinal ligament sustaining chronic mechanical irritation to the dura mater, leading to perforation of the herniated disc by an accidental force.

Evaluation of an automatic fogging disinfection unit.

A new fogging disinfection method was evaluated as a means of disinfecting ward rooms and operating theaters. A temporary room was established where the disinfection effect of fogging was examined. Based on the results, an automatic fogging disinfection unit was developed. This unit was then used in the disinfection of operating theaters, where its safety and effectiveness were examined.To evaluate the results of disinfection, bacterial culture tests were performed on the floor, walls and other areas of the operating theater, and the number of colony forming units was used as an index of effectiveness. Benzalkonium chloride, alkyldiaminoethylglycine, sodium hypochlorite, glutaral and acidic electrolytic water were used for the operating theaters. The average disinfection effect was 90% or better for all disinfectants, except acidic electrolytic water.The newly developed automatic fogging disinfection unit enables safe and effective disinfection, and may be suitable for disinfecting ward rooms and operating theaters.

Deficits of masticatory movements caused by lesions in the orofacial somatosensory cortex of the awake cat.

The purpose of this study was to determine the role of somatosensory cortex (SI) in the control of orofacial movements during eating. We identified perioral and tongue projection regions of the cat SI and destroyed cells in one region by injecting kainic acid. The effects on orofacial behavior were then studied over a period of 4-6 weeks. Cats with unilateral lesions in the perioral region (PL-cats) dropped food from the contralateral side of the mouth in the early phase. Failure in erection of the contralateral whisker hairs during masticatory movements and delay of the masticatory start were observed throughout the experimental period. Furthermore, in the late phase, PL-cats showed prolongations of the masticatory and food intake periods, which were accompanied by the increase in the number of swallows and chewing cycles. Cats with unilateral lesions in the tongue region (TL-cats) showed the prolongation of the masticatory period in the early phase, which was accompanied by the increase in the number of swallows and chewing cycles. TL-cats did not show the prolongation of the food intake period and failure in erection of the contralateral whisker hairs. In both PL- and TL-cats, masticatory and swallowing rhythms were normal.

Horizontal and vertical transfer of mouse endogenous retroviral DNA sequences in schistosomes.

The in situ polymerase chain reaction (PCR) results revealed that mouse type A and type C retroviral sequences were transmitted horizontally from the host to schistosomes. The signals to these retroviral sequences were observed in the nuclei of the mesenchymal and reproductive cells of 8-week Schistosoma japonicum. These signals were also detected in the nuclei of the mesenchymal and reproductive cells and in the cytoplasm of the tegumental tubercles of 24-week S. mansoni. Furthermore, mouse type A retroviral sequence was detected in the DNA extracted from the cercariae of both species. However, mouse type C retroviral sequence and mouse type 2 Alu sequence (B2) were difficult to detect in the cercarial DNA of either species. These findings may indicate that some host sequences are propagated in the schistosome progeny, that is to say, not only horizontal but also vertical transfer of the host gene may occur in schistosomes.

Bilateral receptive field neurons in the hindlimb region of the postcentral somatosensory cortex in awake macaque monkeys.

Single-neuron activities were recorded in the hindlimb region of the primary somatosensory cortex and part of area 5 in awake Japanese monkeys. A total of 1050 units were isolated from five hemispheres of four animals. Receptive fields (RFs) and submodalities were identified for 90% of isolated neurons in areas 3a and 3b. The percentage decreased as the recoding site moved to the more caudal areas. Deep or skin submodality neurons were dominant in area 3a or area 3b, respectively. Deep submodality neurons increased in more caudal areas and were the majority in areas 2 and 5. These observations were consistent with those in the hand and/or digit or arm and/or trunk region. The identified neurons were classified by their RF positions into four types: the foot, leg, foot and leg, or hindlimb and other body parts type. Among 831 identified neurons, 33 neurons had bilateral RFs, 14 had ipsilateral RFs, and the rest (N=784) had contralateral RFs. The relative incidence of neurons with bilateral or ipsilateral RFs among identified neurons was less than 1% in areas 3a, 3b, and 1, and 16% or 25% in areas 2 or 5, respectively. Within areas 2 and 5, the percentage of neurons with bilateral or ipsilateral RFs was significantly smaller in the foot type (5%) than in other RF types (24-57%). RFs of the foot type were on the sole or single toe but never on multiple toes. These observations contrasted with the previous findings that neurons with bilateral RFs were more frequently seen in the hand and/or digit region and that RFs on multiple digit tips were dominant there. The present study thus demonstrated that neurons with bilateral RFs do exist in the hindlimb region. Similarly to the forelimb region, they were found mostly in areas 2 and 5, the caudalmost areas of the postcentral gyrus and hierarchically higher stages in information processing. The relative paucity of neurons with bilateral RFs on the foot, especially those with RFs on multiple toes, may reflect functional differences between the foot and the hand.

Bilateral receptive field neurons and callosal connections in the somatosensory cortex.

Earlier studies recording single neuronal activity with bilateral receptive fields in the primary somatosensory cortex of monkeys and cats agreed that the bilateral receptive fields were related exclusively to the body midline and that the ipsilateral information reaches the cortex via callosal connections since they are dense in the cortical region representing the midline structures of the body while practically absent in the regions representing the distal extremities. We recently found a substantial number of neurons with bilateral receptive fields on hand digits, shoulders-arms or legs-feet in the caudalmost part (areas 2 and 5) of the postcentral gyrus in awake Japanese monkeys (Macaca fuscata). I review these results, discuss the functional implications of this bilateral representation in the postcentral somatosensory cortex from a behavioural standpoint and give a new interpretation to the midline fusion theory.

Localization of mouse type 2 Alu sequence in schistosomes.

Localization of the type 2 Alu sequence (B2), a highly repetitive DNA sequence in the mouse genome, was examined by in situ polymerase chain reaction (in situ PCR) in schistosomes. The signals to the B2 sequence were detected in the cytoplasm of the tegumental membrane and in the nuclei of the mesenchymal, testicular, ovarian and vitelline cells of 8-week Schistosoma japonicum. In contrast, it was difficult to detect any signals of this sequence in 8-week S. mansoni, whereas in 24-week male S. mansoni the signals were observed in the cytoplasm of the tegumental tubercles and in the nuclei of the mesenchymal and testicular cells. On the other hand, in 24-week female S. mansoni the signals were found in the nuclei of the mesenchymal, ovarian and vitelline cells but not found in the tegument. On the contrary, no hybridization band of the B2 sequence was detected in the amplified DNA of 3-week schistosomula of either species. These observations proved that the host DNA sequences existed in restricted schistosome cells and were accumulated in the schistosome body during their development.

Acute exercise causes mitochondrial DNA deletion in rat skeletal muscle.

The present study was conducted to determine the effects of acute overload exercise on mitochondrial DNA and the structure of skeletal muscles. Rats were forced to run for 20 min until reaching complete exhaustion. We detected the large-scale deletion (7052 bp) of mitochondrial DNA by the nested polymerase chain reaction, and also observed mitochondrial ultrastructural changes in the soleus muscle.

Representation of the midline trunk, bilateral arms, and shoulders in the monkey postcentral somatosensory cortex.

Single neuronal activities were recorded in the arm/trunk region of the postcentral gyrus in awake Japanese monkeys. A total of 1608 units were isolated from four hemispheres of two animals, and receptive fields (RFs) and submodalities were identified in 1162 units. Deep or skin submodality neurons were dominant in area 3a or area 3b, respectively. The deep/skin ratio increased as the recording site moved from area 3b to the more caudal areas. In areas 3a and 3b, neuronal RFs were almost exclusively on either the arm or trunk. In areas 2 and 5, neurons with RFs on the trunk decreased and those with RFs on the hand or covering more than one body part, etc. increased. We found a total of 107 neurons with bilateral RFs and 56 with ipsilateral RFs, while the rest (n=999) were with contralateral RFs. Bilateral or ipsilateral neurons of skin submodality (n=37) were found in areas 1, 2, and 5. Twenty six (70%) had RFs on the trunk and/or occiput, five on the forelimb, and the rest (n=6) on both the trunk and forelimb (the combined type). Among 33 skin bilateral neurons, 90% (n=30) had RFs across the midline. Bilateral or ipsilateral neurons responding to joint manipulation (n=104) were found in areas 2 and 5. Most of them were activated by manipulation of the shoulder and/or elbow (the proximal type, n=72, 69%). There were 25 neurons of the combined type (both the proximal and distal joints were effective, 24%). Bilateral or ipsilateral neurons of deep-others submodality (n=20) were found in areas 1, 2, and 5. The forelimb type (n=12, 60%) was dominant in this category. The combined-type neurons in both the skin- and joint-manipulation categories were found only or mostly in area 5. These results indicate the presence of hierarchical processing for bilateral as well as contralateral information within the arm/trunk region of the postcentral gyrus.

Hierarchical somatosensory processing.

Recent studies of the postcentral and additional somatosensory cortices support a hierarchical scheme for information processing. In the postcentral gyrus, the complexity of receptive field properties increases with caudal progression from area 1. It has been reported that the anterior bank of the intraparietal sulcus, the caudalmost part of the postcentral gyrus, is responsible for the systematic integration of bilateral body parts, as well as of somatic and visual information.