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To identify the vector species for Shimokoshi type Orientia tsutsugamushi, a survey of larval trombiculid mites was conducted in Yamagata Prefecture, Japan from April to May 2012. In all, 2889 larval trombiculid mites were obtained from 21 Apodemus speciosus rodent hosts, 2600 of which were morphologically classified into eight species in three genera. After screening of O. tsutsugamushi DNA in individual larval trombiculid mites using real-time PCR targeting the 16S ribosomal RNA gene, serotype-specific nested PCRs targeting the 56 kDa protein gene were performed, followed by sequencing analysis. As a result, Shimokoshi type O. tsutsugamushi DNA was identified from 3 (1.9%) of 157 Leptotrombidium palpale. This is the first study to identify Shimokoshi type O. tsutsugamushi DNA in L. palpale. The results indicate that L. palpale is a possible vector for Shimokoshi type O. tsutsugamushi.

SUMMARYClimate change, by its influence on the ecology of vectors might affect the occurrence of vector-borne diseases. This study examines the effects of meteorological factors in Japan on the occurrence of scrub typhus, a mite-borne zoonosis caused byOrientia tsutsugamushi. Using negative binomial regression, we analysed the relationships between meteorological factors (including temperature, rainfall, snowfall) and spring–early summer cases of scrub typhus in Yamagata Prefecture, Japan, during 1984–2014. The average temperature in July and August of the previous year, cumulative rainfall in September of the previous year, snowfall throughout the winter, and maximum depth of snow cover in January and February were positively correlated with the number of scrub typhus cases. By contrast, cumulative rainfall in July of the previous year showed a negative relationship to the number of cases. These associations can be explained by the life-cycle ofLeptotrombidium pallidum, a predominant vector of spring–early summer cases of scrub typhus in northern Japan. Our findings show that several meteorological factors are useful to estimate the number of scrub typhus cases before the endemic period. They are applicable to establish an early warning system for scrub typhus in northern Japan.

Although several studies have investigated the relationship between dietary nutrient intake and microalbuminuria, no study of an Asian population has been reported. The present study investigates the relationship between dietary intake and microalbuminuria in a general Japanese population.We analyzed 675 men and 924 women who did not have diabetes. Participants who had a urinary albumin-to-creatinine ratio (UACR) ≥300 mg/g, who did not complete a questionnaire regarding food frequency and who did not provide complete urine measurements were excluded. Nutrient intake was assessed by validated food frequency questionnaire. Microalbuminuria was defined as UACR ≥30 mg/g. The relationship between dietary nutrient intake and microalbuminuria was examined using a multiple logistic regression model adjusted for age, total energy intake, body mass index, smoking status, systolic blood pressure and use of antihypertensive medication.No significant association was observed among the men. The multiple adjusted odds ratios (95% confidence interval) of having microalbuminuria per 1 standard deviation increase in total protein (%kcal), animal protein (%kcal), animal protein (g/day), animal fat, niacin, carbohydrate and β-cryptoxanthin among the women were 1.33 (1.07-1.66), 1.35 (1.09-1.66), 1.42 (1.08-1.88), 1.29 (1.05-1.59), 1.28 (1.04-1.57), 0.73 (0.58-0.92) and 0.76 (0.59-0.996), respectively. The multiple adjusted odds ratio (95% confidence interval) of having microalbuminuria in the highest quintile of n-3 polyunsaturated fatty acids compared with the lowest was 2.16 (1.03-4.54).Less animal protein and more β-cryptoxanthin in the diet might help to prevent microalbuminuria. Prospective studies including controlled trials are required to confirm this conclusion.

To determine the Karp-type Orientia tsutsugamushi subtype in northern Japan, i.e., Yamagata, Niigata, and Akita Prefectures, we analyzed the partial nucleotide sequence of the 56-kDa protein-encoding gene of 30 isolates from scrub typhus cases. Based on sequencing results, we classified isolates into two groups of 27 and 3 isolates. Nucleotide sequences of 27 isolates were homologous to the yeo-joo strain, classified as a JP-1 subtype. The three isolates were each homologous to a stain of CMM1, KNP1, or KNP2, classified as JP-2 subtypes. Phylogenetic tree analysis showed the 27 isolates forming a cluster with the yeo-joo strain and the three isolates with the CMM, KNP1, and KNP2 strains and therefore belonging to these subtypes. The Karp-type O. tsutsugamushi JP-2 subtype predominates in Japan, the JP-1 subtype probably the predominates in the area investigated. O. tsutsugamushi JP-1 subtype strains must therefore be isolated from subjects in this area and comprehensively studied.

Electroless nickel plating waste liquor contains a large amount of nickel ions, but nickel ions in waste liquor have not been recovered for technical and economic reasons. If the recovery of nickel ions is effectively carried out, nickel ions could be recycled as a nickel source for electroless plating liquor. The process to recover nickel ions from electroless plating waste liquor was investigated by using a solvent extraction method. The existence of various phosphate species and organic acids in the waste liquor causes the incomplete extraction of nickel ions with any single extractant due to the complex formation between nickel ions and them. The application of solvent extraction using a synergistic effect makes possible to separate and recover 90% or more of nickel ions in the waste liquor. The extractant mixtures of acidic extractant such as D2EHPA and PC-88A, and another extractants with electron-donating ability such as nicotinic acid dodecyl ester and iso-nicotinic acid dodecyl ester are used for this purpose.

Of 95 Tsutsugamushi disease case occurring in Yamagata prefecture from 1999 to 2006, four-all women-involved the O. tsutsugamushi Kawasaki serotype. The three major symptoms were fever, exanthema, and eschar present from mid-October to early November. Serodiagnosis by indirect immunofluoresence assay showed elevated IgG and IgM antibody titers against the Kawasaki serotype antigen, with IgM higher than IgG. Nested PCR detected 56-kDa DNA in three of the cases. DNA was amplified in Kawasaki-specific PCR. Two cases for which sequencing was done using nested PCR-amplified DNA showed an identity of 99.8% for the Kawasaki strain (Accession number: M63383). These results confirmed the occurrence of Tsutsugamushi disease infection involving Kawasaki serotype in Yamagata prefecture.

We examined water from 182 non-circulating hot spring bathing facilities in Japan for possible Legionella occurrence from June 2005 to December 2006, finding Legionella-positive cultures in 119 (29.5%) of 403 samples. Legionellae occurrence was most prevalent in bathtub water (39.4%), followed by storage tank water (23.8%), water from faucets at the bathtub edge (22.3%), and source-spring water (8.3%), indicating no statistically significant difference, in the number of legionellae, having an overall mean of 66 CFU/100mL. The maximum number of legionellae in water increased as water was sampled downstream:180 CFU/100 mL from source spring, 670 from storage tanks, 4,000 from inlet faucets, and 6,800 from bathtubs. The majority--85.7%--of isolated species were identified as L. pneumophila : L. pneumophila serogroup (SG) 1 in 22%, SG 5 in 21%, and SG 6 in 22% of positive samples. Multivariate logistic regression models used to determine the characteristics of facilities and sanitary management associated with Legionella contamination indicated that legionellae was prevalent in bathtub water under conditions where it was isolated from inlet faucet/pouring gate water (odds ratio [OR] = 6.98, 95% confidence interval [CI] = 2.14 to 22.8). Risk of occurrence was also high when the bathtub volume exceeded 5 m3 (OR = 2.74, 95% CI = 1.28 to 5.89). Legionellae occurrence was significantly reduced when the bathing water pH was lower than 6.0 (OR = 0.12, 95% CI = 0.02 to 0.63). Similarly, occurrence was rare in inlet faucet water or the upper part of the plumbing system for which pH was lower than 6.0 (OR = 0.06, 95% CI = 0.01 to 0.48), and when the water temperature was maintained at 55 degrees C or more (OR = 0.10, 95% CI = 0.01 to 0.77). We also examined the occurrence of amoeba, Mycobacterium spp., Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus in water samples.

Obesity is associated with environmental factors; however, information about gene-environment interactions is lacking. We aimed to elucidate the effects of gene-environment interactions on obesity, specifically between genetic predisposition and various obesity-related lifestyle factors, using data from a population-based prospective cohort study. The genetic risk score (GRS) calculated from East Asian ancestry single-nucleotide polymorphisms was significantly associated with the body mass index (BMI) at baseline (P

For forty-three clinical test values presumably associated to common complex human diseases, we carried out a genome-wide association study using 600K SNPs in a general Japanese population of 1,639 individuals (1,252 after quality control procedures) drawn from a regional cohort, followed by a replication study for statistically significant SNPs (p = 1.95 × 10(-9)-8.34 × 10(-39)) using an independent population of 1,671 from another cohort. In this single two-stage study, we newly found strong and robust associations of common variants at the ABO histo-blood glycosyltransferase locus in 9q32 with the plasma levels of pancreatic lipase (P-LIP), in addition to successful confirmation of the known ABO association of angiotensin converting enzyme (ACE) independent of the ACE1 gene in 17q23.2 with the ACE level. Our results are compatible with the previously reported association between the ABO gene and pancreatic cancer, and show that the effect of these common variants at the ABO locus on the P-LIP and ACE levels is largely opposing and pleiotropic.

Background Patients increasingly turn to the Internet for information on medical conditions, including clinical news and treatment options. In recent years, an online patient community has arisen alongside the rapidly expanding world of social media, or “Web 2.0.” Twitter provides real-time dissemination of news, information, personal accounts and other details via a highly interactive form of social media, and has become an important online tool for patients. This medium is now considered to play an important role in the modern social community of online, “wired” cancer patients. Results Fifty-one highly influential “power accounts” belonging to cancer patients were extracted from a dataset of 731 Twitter accounts with cancer terminology in their profiles. In accordance with previously established methodology, “power accounts” were defined as those Twitter accounts with 500 or more followers. We extracted data on the cancer patient (female) with the most followers to study the specific relationships that existed between the user and her followers, and found that the majority of the examined tweets focused on greetings, treatment discussions, and other instances of psychological support. These findings went against our hypothesis that cancer patients’ tweets would be centered on the dissemination of medical information and similar “newsy” details. Conclusions At present, there exists a rapidly evolving network of cancer patients engaged in information exchange via Twitter. This network is valuable in the sharing of psychological support among the cancer community.

To identify the vector species for Shimokoshi type Orientia tsutsugamushi, a survey of larval trombiculid mites was conducted in Yamagata Prefecture, Japan from April to May 2012. In all, 2889 larval trombiculid mites were obtained from 21 Apodemus speciosus rodent hosts, 2600 of which were morphologically classified into eight species in three genera. After screening of O. tsutsugamushi DNA in individual larval trombiculid mites using real-time PCR targeting the 16S ribosomal RNA gene, serotype-specific nested PCRs targeting the 56 kDa protein gene were performed, followed by sequencing analysis. As a result, Shimokoshi type O. tsutsugamushi DNA was identified from 3 (1.9%) of 157 Leptotrombidium palpale. This is the first study to identify Shimokoshi type O. tsutsugamushi DNA in L. palpale. The results indicate that L. palpale is a possible vector for Shimokoshi type O. tsutsugamushi.

To determine the Karp-type Orientia tsutsugamushi subtype in northern Japan, i.e., Yamagata, Niigata, and Akita Prefectures, we analyzed the partial nucleotide sequence of the 56-kDa protein-encoding gene of 30 isolates from scrub typhus cases. Based on sequencing results, we classified isolates into two groups of 27 and 3 isolates. Nucleotide sequences of 27 isolates were homologous to the yeo-joo strain, classified as a JP-1 subtype. The three isolates were each homologous to a stain of CMM1, KNP1, or KNP2, classified as JP-2 subtypes. Phylogenetic tree analysis showed the 27 isolates forming a cluster with the yeo-joo strain and the three isolates with the CMM, KNP1, and KNP2 strains and therefore belonging to these subtypes. The Karp-type O. tsutsugamushi JP-2 subtype predominates in Japan, the JP-1 subtype probably the predominates in the area investigated. O. tsutsugamushi JP-1 subtype strains must therefore be isolated from subjects in this area and comprehensively studied.

Of 95 Tsutsugamushi disease case occurring in Yamagata prefecture from 1999 to 2006, four-all women-involved the O. tsutsugamushi Kawasaki serotype. The three major symptoms were fever, exanthema, and eschar present from mid-October to early November. Serodiagnosis by indirect immunofluoresence assay showed elevated IgG and IgM antibody titers against the Kawasaki serotype antigen, with IgM higher than IgG. Nested PCR detected 56-kDa DNA in three of the cases. DNA was amplified in Kawasaki-specific PCR. Two cases for which sequencing was done using nested PCR-amplified DNA showed an identity of 99.8% for the Kawasaki strain (Accession number: M63383). These results confirmed the occurrence of Tsutsugamushi disease infection involving Kawasaki serotype in Yamagata prefecture.

We examined water from 182 non-circulating hot spring bathing facilities in Japan for possible Legionella occurrence from June 2005 to December 2006, finding Legionella-positive cultures in 119 (29.5%) of 403 samples. Legionellae occurrence was most prevalent in bathtub water (39.4%), followed by storage tank water (23.8%), water from faucets at the bathtub edge (22.3%), and source-spring water (8.3%), indicating no statistically significant difference, in the number of legionellae, having an overall mean of 66 CFU/100mL. The maximum number of legionellae in water increased as water was sampled downstream:180 CFU/100 mL from source spring, 670 from storage tanks, 4,000 from inlet faucets, and 6,800 from bathtubs. The majority--85.7%--of isolated species were identified as L. pneumophila : L. pneumophila serogroup (SG) 1 in 22%, SG 5 in 21%, and SG 6 in 22% of positive samples. Multivariate logistic regression models used to determine the characteristics of facilities and sanitary management associated with Legionella contamination indicated that legionellae was prevalent in bathtub water under conditions where it was isolated from inlet faucet/pouring gate water (odds ratio [OR] = 6.98, 95% confidence interval [CI] = 2.14 to 22.8). Risk of occurrence was also high when the bathtub volume exceeded 5 m3 (OR = 2.74, 95% CI = 1.28 to 5.89). Legionellae occurrence was significantly reduced when the bathing water pH was lower than 6.0 (OR = 0.12, 95% CI = 0.02 to 0.63). Similarly, occurrence was rare in inlet faucet water or the upper part of the plumbing system for which pH was lower than 6.0 (OR = 0.06, 95% CI = 0.01 to 0.48), and when the water temperature was maintained at 55 degrees C or more (OR = 0.10, 95% CI = 0.01 to 0.77). We also examined the occurrence of amoeba, Mycobacterium spp., Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus in water samples.

Nosocomial infection caused by methicillin-resistant Staphylococcus aureus (MRSA) occurred at a major in Yamagata prefecture hospital between May 2004 and June 2005. We studied pulsed-field gel electrophoresis patterns, antimicrobial susceptibility patterns, and bacteriological features, such as coaglase type for eight isolates, including two of methicillin-resistant Staphylococcus epidermidis (MRSE). Our results suggest that this case was caused by a single strain of multidrug-resistant S. aureus. These 8 clinical isolates indicated reduced susceptibility to vancomycin and teicoplanin. PCR assay results for detection of the staphylococcal vanA, vanB, and vanC gene were all negative as all isolates. In transmission electron microscopy, cell walls appeared thicker than those of a susceptible strain from food poisoning. MRSA with reduced susceptibility to glycopeptide antibiotics may not be treated successfully with vancomycin or teicoplanin, making it important to closely observe MRSA with reduced susceptibility to glycopeptide antibiotics.

“Spatial statistics” is an academic field that deals with the statistical analysis of spatial data, and has been applied to econometrics and various other policy fields. These methods are easily applied by hematologists and oncologists using better and much less expensive software. To encourage physicians to use these methods, this review introduces the methods and demonstrates the analyses using R and FleXScan, which can be freely downloaded from the website, with sample data. It is demonstrated that spatial analysis can be used by physicians to analyze hematological diseases. In addition, applying the technique presented to the investigation of patient prognoses may enable generation of data that are also useful for solving health policy-related problems, such as the optimal distribution of medical resources.

Frequency and morphological characteristics of the intersegmental anastomoses between the spinal roots were investigated in 100 adult spinal cords from the cervical to lumbar segments. The frequencies of dorsal root anastomoses were 61, 7, and 22% of the cervical, thoracic, and lumbar cords, respectively. On the other hand, the incidence of anastomosis between the ventral roots was significantly low in both the cervical (10%) and lumbar (5%) cords as compared with that between the dorsal roots in these regions (P less than .01). No anastomotic connections were found in the thoracic ventral roots. The anastomoses were classified into four types: types A and B; the borders between the spinal segments were cranially and caudally shifted, respectively; type C, anastomosis attached to the spinal cord at the border between the segments; and type D, anastomosis bridged between the adjacent rootlets and coursing parallel to the cord. The proportions of the four types at each spinal level disclosed that type A was most commonly observed compared with the other three types in the dorsal roots (P less than .01). In the lumbar cord, the proportion of type C anastomosis between the dorsal roots increases noticeably toward the sacral level, while a complementary decrease occurred in type A. In the cervical ventral roots, types C and D predominated over the other two types (P less than .01). The lumbar ventral roots contained types B and/or C. Type D anastomosis occurred exclusively in the cervical segments.

Summary Following the injection of HRP into the superior colliculus (SC), labeled neurons were found ipsilaterally in the rostral halves not only of the pars lateralis (SNL) but also of the pars reticulata of the substantia nigra (SNR). HRP-positive cells in the SNR were distributed along the ventral-to-lateral margin in the rostral half of the SNR, forming a thin longitudinal lamina. No nigral neurons were marked with HRP after the injection into the superficial layers of the SC. When HRP or wheat germ agglutinin conjugated with HRP (WGA-HRP) was placed in the inferior colliculus (IC), retrogradely labeled neurons were observed ipsilaterally in the caudal half of the SNL, but not in the SNR. A single injection of PI (propidium iodide) into each colliculus demonstrated that a small number of labeled SNL neurons fluorescing orange-red concomitantly emitted green monoamine fluorescence. However, no SNR neurons projecting to the SC showed such endogenous catecholamine fluorescence. Combined injection of PI and DAPI (4′, 6-diamidino-2-phenylindol · 2HCl) into the SC and the IC resulted in double labeling of a small number of neurons in the intermediate part of the SNL. Application of HRP into the thalamic ventromedial nucleus (VM) labeled many neurons in the ipsilateral SNR extending throughout its length. In cases with combined injection of the two fluorescent dyes in the SC and the VM, a considerable number of double labeled neurons was observed mainly in the ventral part of the SNR.

The extraocular muscles in a mutant microphthalmic strain of rat were studied. The eyeball of this strain of rat is reduced to about a third in diameter of that of the normal rat. Nevertheless, in the orbit of the mutant rat, every one of the extraocular muscles was identified; their origins and courses were the same as in the normal rat, but differences existed in the insertions. These insertions could be classified into three groups: Group A (retractor bulbi): like normal insertion into the eyeball. Group B (superior rectus and superior oblique): attachment of tendonlike insertions to each other; these muscles come from opposite directions and form a loop. Group C (lateral, medial, and inferior rectus and inferior oblique): insertion into connective tissue surrounding the reduced eyeball. The volume of each muscle of the mutant rat was smaller than that of the normal rat; moreover, significant differences existed in the degree of reduction in the volume of each muscle group classified according to the change of insertion. In the group A muscle the volume was only 33% of the normal volume, whereas group B was 74% and group C was about half of normal.

Morphogenesis of the eye was studied in a new strain of micro-phthalmic rat. Abnormalities were noted immediately after the formation of the optic cup. The inner layer in the central part of the optic cup was relatively thick and contained many mitotic figures, whereas that of the marginal part was thin and contained only a few. The transitional point in the inner layer between the central and the marginal parts was well marked. This is evidently due to the extreme growth inhibition of the inner layer at the marginal part. At the early developmental stage, an area of the inner layer corresponding to the transitional point protruded toward the lens because the central part of the inner layer continued to differentiate. The differentiation and the protrusion of the inner layer proceeded variably at the later stages depending on the degree of the growth inhibition. The eyes were classified into three groups: Group A–the retina was recognized as a cyst consisting of the pigment layer and the pigment-layerlike structure which originated from the inner layer; group B-the neural retina and its layered structure were inverted; group C-abnormalities, such as the destruction of the lens, were observed. Although previous authors who studied eye mutants suggested the vascular abnormality as the primary cause of the production of abnormal eyes, we feel that this is not the case in our animals.

A quantitative analysis of the oculomotor, trochlear, and abducens nuclei was carried out in the mutant microphthalmic rat. In this strain of rat, the eyeball is reduced to about one-third in diameter, and there is no optic nerve. Nevertheless, this strain possesses all the types of extraocular muscles; however, the volume of these muscles is reduced from 33 to 74% of the normal values. The oculomotor, trochlear, and abducens nuclei in this mutant rat were found in the same location as in the normal ones. Moreover, the neurons in these nuclei in the microphthalmic rat did not appear to be any different from those in the controls. The neuronal population of these nuclei was reduced by 63% (oculomotor), 50% (trochlear), and 61% (abducens) of normal values, respectively. The long axis of all neurons of these nuclei in the microphthalmic and normal rats was measured. In all three nuclei of both strains, the size histograms showed a unimodal distribution ranging from 10 to 35 micron, with peaks at 20 to 25 micron. There was no significant difference between the normal and mutant strains. Consequently, the only influence of the shrinkage of the muscles which they supply was seen in the reduction of the cell populations of these nuclei.

The uncrossed optic projection to the medial terminal nucleus of the accessory optic system was studied in adult rats with hereditary unilateral microphthalmia. The vestigial eye of the mutant completely lacks the optic nerve. After injection of HRP into the remaining eye the ipsilateral labeled fibers of the accessory optic system via the superior fasciculus distinctly covered the three terminal nuclei. No ipsilateral inferior fasciculus of the accessory optic system was labeled. Aberrant expansion of the uncrossed superior fasciculus fibers was observed in the medial terminal nucleus.

Following lesions at various levels of the spinal cord of rabbits, rats, and cats, degenerating fibers were found in the gray matter (GC) surrounding the aqueduct and the third and fourth ventricles in materials stained with silver impregnation methods. These fibers ascend in the medial lemniscus and contribute to the GC at various levels; they are collectively referred to as the spinoperiventricular fiber system. A small number of fibers from all spinal segments enter the GC at the following four levels: the hypoglossal nucleus and the locus ceruleus, the intercollicular level, and the rostral level of the nucleus of Darkschewitsch. As the locus of spinal injury shifts from caudal to rostral segments, the region of fibers entering the GC through the reticular formation extends rostrally from each of these four levels. Fibers ascending rostralmost in the GC reach the dorsal part of the posterior hypothalamic region. Some exceptional fibers ascending in the medial lemniscus terminate in the lateral part of the posterior hypothalamic region. Other fibers coursing along the spinotectal tract terminate in the GC at the intercollicular level.

Quantitative morphological changes in the superior colliculus (SC) and the parabigeminal nucleus (PB) were studied in hereditary bilaterally microphthalmic rat, which lacks the optic nerve completely. Volumes of the retinorecipient superficial collicular layers of SC (SCS) to the central gray matter were decreased by 35% with respect to the normal. However, the cell density in SCS was increased as much as 150% of the normal. The stratum griseum superficiale was packed densely and irregularly with small-sized round nerve cells. The stratum opticum of the mutant rat appeared as a narrow band with few fiber components, but it contained some medium-sized polygonal neurons. No significant changes were found in the deeper layers of the microphthalmic SC. Bilaterally microphthalmic PB reduced both its volume and cellular density per unit area (about 30 and 75% of the normal, respectively). Furthermore, in contrast to the normal rat, the mutant PB could not be subdivided into the dorsal, middle and ventral subgroups.

The cell type of the rat superior colliculus was investigated using the modified Golgi-Cox method. The superior colliculus was found to be composed of two laminar sets, which develop different neuronal organizations. The superficial layers, containing the zonal-to-optic strata, consisted of many neurons of variable size and shape. However, on the basis of the profile and the orientation of the dendritic fields, cells of the superficial layers were classified into four types: the horizontal, the cylindrical, the reversed conical, and the multipolar cells. Some of the cells were further subdivided according to the orientation and the width of dendritic fields. The deep layers which included the middle gray to deep white laminae were characterized by medium-sized and large multipolar neurons. In addition to these cells with global or ellipsoidal dendritic fields, another two types of cells, vertical and horizontal neurons, were also included.

Neurons of the dorsal lateral geniculate nucleus (LGNd) in the microphthalmic rat were examined by the Golgi-Cox method. LGNd neurons in the microphthalmic rat were classified into the multipolar (I) and bipolar (II) types as in the normal rat. The multipolar type was further divided into two subclasses (Ia and Ib) on the basis of their dendritic patterns. The proximal portion of their primary dendrites was thinner than in normal LGNd neurons. The Ia cells had 6–7 primary dendrites extending radially, while the Ib cells had 3–4 primary dendrites spreading primarily parallel to the optic tract. Type II cells had two or three primary dendrites emerging from the cell bodies. In both types, primary dendrites were shorter in length or less branched than usual. These results suggested that LGNd neurons in the microphthalmic rat had smaller dendritic fields than those in the normal rat.

The cytoarchitecture and the cell type of the rat parabigeminal body were studied. The parabigeminal nucleus was divided into three small subgroups. The middle subgroup was found to be packed mainly with 10- to 16-μm rounded or polygonal cells, which were stained deeply. Fusiform cells of 10 to 16 × 6 to 8 μm formed the dorsal and ventral portions. The parabigeminal neurons which were impregnated with the modified Golgi-Cox method could be classified into four cell types, according to the whole profile, orientation, and width of the dendritic field. Neurons with the pyramidal dendritic field were found in the middle subgroup of the structure and the axons emerged medially toward the mesencephalic reticular formation. They were considered to be projection cells. Nerve cells with the hemispherical dendritic field were common in the dorsal and ventral parabigeminal subgroups. The arrangement of the dendritic field of the aforementioned neurons was variable from cell to cell, reflecting differences in their plane of sectioning. The cylindrical neurons appeared in the medial part of the dorsal parabigeminal subgroup. Their dendrites extended along the medial and dorsal boundary of the nucleus. Both the hemispherical and cylindrical cells were judged to be intrinsic neurons because no axon exceeded beyond the whole extent of the parabigeminal body. There is a probability that the multipolar neurons are aberrant reticular elements.

The topographic organization of neurons in the dorsal nucleus of the lateral lemniscus (DNLL) which project to the superior and inferior colliculi was studied using the retrograde horseradish peroxidase (HRP) and the fluorescent double labeling methods. Neurons projecting to the superior colliculus (SC) are situated in the rostral portion of the DNLL, whereas those to the inferior colliculus (IC) are found in the caudal area of this nucleus. These two portions are completely separated from each other and no neurons projecting to both the SC and the IC are observed. In the dorsolateral part of the rostral portion of the DNLL, neurons projecting to the ipsilateral SC are found, whereas neurons projecting to the contralateral SC are located in the central to medial part of the nucleus, but no neurons sending collateral axons to both sides of the SC were observed. Neurons located in the central part of the caudal area of the DNLL project to the ipsilateral IC and neurons in the lateral and medial parts project contralaterally to the IC. Some of the neurons in the caudal part of the DNLL have divergent axonal branching projecting to both sides of the IC. In the ventral nucleus of the lateral lemniscus, labeled neurons were observed only when the HRP was injected into the ipsilateral IC.

The Nauta silver degeneration technique was used to study the interconnections of the frontal cortex of the cat. The sensorimotor area is found to be highly organized through intrinsic short association fibers. However, less specific connections are-revealed with other areas; for example, no direct fibers are recognized as passing from the sensorimotor cortex to the visual area. In the sensorimotor area, the association fibers from the first (SI) to the second somatic sensory area (SII) are generally denser than those passing in the reverse direction, particularly in regard to the leg subdivisions. Such a difference in density is less striking in regard to the arm subdivisions and much less in the face subdivisions. Long association fibers arise only from the first face area to the middle suprasylvian sulcus, a connection which may correspond to the superior longitudinal fasciculus in man. The number of callosal fibers connecting the homotopical regions between both hemispheres differs for each portion of the cortex. Callosal interconnections are doubtful for the gyrus proreus and the medial portion of both the anterior and posterior sigmoid gyri, While they appear sparse in the lateral portion of the latter gyri. Dense interconnections, by contrast, are seen in the coronal and anterior ectosylvian gyri. The degenerating fibers seen in layers V and VI mainly appear to represent fibers of passage, and those in layers III and IV seem to be Preterminal fibers.

The descending pathways of the nucleus of the optic tract (pars lateralis) (NOTL) in the rat were examined in Nauta-Gygax impregnated sections and further confirmed by the horseradish peroxidase labeling technique. Following stereotatic lesions in the NOTL, visual cortex, and superior colliculus, projections which orginate in the NOTL were identified by elimination of the tectofugal and tectopetal fibers of the superior colliculus. The descending fibers from the NOTL appeared to be organized into three bundles. (1) The NOTL-contralateral NOTL fibers, which connect bilateral NOTLs through a part of the posterior commissure. (2) The NOTL-nucleus tegmenti pontis and inferior olivary nucleus fibers, which project to the ventromedial part of the nucleus tegmenti pontis and the dorsal cap of the inferior olivary nucleus, ipsilaterally to the NOTL. (3) The NOTL-pontine nuclei fibers, which terminate within the medial one-third of the pars lateralis of the ipsilateral pontine nuclei with topical relations.

Ascending projections to the lateral thalamic nuclear group from the substantia grisea centralis (SGC) were studied by injections of wheat germ agglutinin-conjugated with HRP (WGA-HRP) into the laterodorsal (LD) and lateroposterior (LP) thalamic nuclei. The present study demonstrated that the pars ventralis of the SGC at the levels of the intercollicular region and of the locus ceruleus sent fibers to both the LD and LP on both sides with homolateral predominance. Distribution pattern and morphological characteristics of the LD-projection neurons in the SGC were similar to those of SGC-LP projection cells. WGA-HRP injections into the LD or LP labeled also a considerable number of neurons in the dorsal raphe nucleus and the dorsal tegmental nucleus bilaterally with homolateral predominance, but the nucleus of Darkschewitsch contained labeled neurons only after the LD injection.

Cells of origin of the tecto-LP (lateroposterior nucleus of the thalamus) projection and the tecto-LGNd (dorsal nucleus of the lateral geniculate body) projection were studied in the albino rat by means of retrograde transport of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP). Tecto-LGNd neurons with small spindle form were located in the stratum griseum superficiale of the superior colliculus (SC), whereas tecto-LP neurons with polygonal shape were found in the stratum opticum of the SC.

Neurons of the lateral part of the ventral lateral geniculate nucleus in the microphthalmic rat were examined by the Golgi-Cox method. These neurons were divided into the same three types as normal neurons. However, the number of branches and the length of primary dendrites of these neurons were fewer and shorter, and the size of their perikarya was smaller, compared with normal cases.

Tecto-thalamic projections in the hereditary bilaterally microphthalmic rat were studied by means of WGA-HRP injection into the dorsal lateral geniculate nucleus (LGNd) and the lateroposterior thalamic nucleus (LP). Histological study in the mutant rats showed that whereas LGNd and superficial layers of the superior colliculus (SC) suffered from a remarkable reduction in size, LP had no histological changes as compared to the normal animals. Unilateral injection of the tracer into the microphthalmic LGNd showed that WGA-HRP positive neurons were present mostly in the ipsilateral str. griseum superficiale (SGS) of the SC. However, the number of labeled SGS neurons of the microphthalmic animals was about 3% of the normal. Although cell bodies of the normal tecto-LGNd neurons in the SGS were spindle-form in shape and issued one or two proximal dendrites from each pole, the microphthalmic tecto-LGNd neurons showed an irregular contour and their dendrites were not so intensively labeled. Unilateral injections of WGA-HRP into the LP revealed that the tecto-LP neurons were mainly distributed in the ipsilateral str. opticum of the colliculus. (SO) in both normal and microphthalmic animals. However, the number of labeled SO cells in the microphthalmic rat was about one-half of the normal. Furthermore, the size of labeled tecto-LP neurons was smaller than that of the normal ones, and they showed irregular round to oval cell bodies with equivocally labeled dendrites, in contrast to the normal tecto-LP neurons with polygonal cell bodies extending three or more dendrites in a radial fashion. These results indicate that there exist the tecto-LGNd and -LP projection neurons in the microphthalmic rat and that their laminally segregated projection is fundamentally preserved. However, the number of the tecto-thalamic projection neurons, especially of the tecto-LGNd cells, was markedly diminished in the mutant tectum compared to normals.

Reciprocally bilateral connections between the superior colliculus and the suprageniculate nucleus have been studied in the rat, using the anterograde and retrograde transport techniques of HRP. In those cases where the HRP deposit was restricted to the superficial layers of the colliculus, anterogradely labeled fibers and retrogradely labeled neurons were observed in the ipsilateral suprageniculate nucleus. However, upon HRP injection extended into the intermediate layers of the colliculus, the number of labeled fibers and neurons was not only increased ipsilaterally but were also observed in the contralateral suprageniculate nucleus. The density of the labeled fibers and the number of labeled neurons was always greater in the ipsilateral side. These results show that the suprageniculate nucleus and the superior colliculus are connected reciprocally and bilaterally, with an ipsilateral dominance.

The dorsal lateral geniculate nucleus (CGLd) of the hereditary unilaterally microphthalmic rats showed a diminution of volume and an increase of neuronal density on the contralateral side of the vestigial eye without the optic nerve (about 60 and 160% of the normal, respectively; P less than 0.001). No significant changes were observed in the ipsilateral CGLd. Uncrossed retino-CGLd and -tectal projections were studied using the anterograde axonal transport of HRP in adult rats with the congenital unilateral microphthalmia. Aberrant expansions of the uncrossed retinal projection widely covered CGLd and the superficial layers of the superior colliculus (SCS). The distribution pattern of expanded uncrossed retinal pathway in the mutant was essentially similar to that of neonatally one-eyed rats.

Studies were made on whether hereditary microphthalmic rats (1), which are congenitally blind, showed a hyperglycemic response to intracerebroventricular injection of 2-deoxy-D-glucose (2DG) in their subjective light period. In contrast to previous findings in normal rats in which 2DG injection caused light-cycle dependent hyperglycemia (2) and bilateral lesion of the suprachiasmatic nucleus (SCN) completely abolished this hyperglycemia (3), 2DG injection caused no and only slight hyperglycemia in male and female rats with hereditary microphthalmia, respectively. Gross and histological examinations indicated that these rats had no optic nerve or retinohypothalamic tract and that their SCN had an abnormal structure. Locomotive activity recordings showed that all the blind rats had a free-running circadian activity rhythm. These findings suggest that the projection sites of the retinohypothalamic tract to the SCN are involved in the mechanism of the hyperglycemic response to 2DG, but that neural cells, which may be responsible for the generation of circadian rhythms, are not. We have reported that when adult rats were blinded by orbital enucleation, their hyperglycemic response to 2DG was suppressed temporarily 3–5 weeks after the operation, but that their plasma insulin level was basically higher and increased further after 2DG injection during this period (4). In congenitally blind rats, however, the basal plasma insulin level was not higher and the level did not change after 2DG treatment. This difference is discussed from the view point of the role of the premature SCN in regulation of the plasma insulin concentration.

The distribution and morphological characteristics of the geniculotectal neurons from the lateral part of the ventral lateral geniculate nucleus in the hereditary microphthalmic rat were examined by the WGA-HRP method. Unilateral injection of the tracer into the microphthalmic superior colliculus showed that WGA-HRP-positive neurons were present in the ipsilateral lateral part of the ventral lateral geniculate nucleus. However, the number of labeled geniculolectal neurons of the microphthalmia was about 50% that of the normal rats. Furthermore, the size of labeled geniculotectal neurons of the microphthalmia was smaller and their dendrites were shorter than those of normal rats. These results demonstrated that, although geniculotectal neurons of the microphthalmic lateral part of the ventral lateral geniculate nucleus could differentiate just as in the normal rat, the size and number of microphthalmic geniculotectal neurons were remarkably smaller and fewer than those of normal rats. Moreover, the dendrites of microphthalmic geniculotectal neurons were less branched than usual.

Publisher Summary This chapter describes projections of the motor, somatic sensory, auditory, and visual cortices in cats. A number of morphological studies on projections from the sigmoid and coronal gyri to the thalamus have been performed with the Marchi method. The distribution pattern of preterminal degenerating fibers observed following lesions in the sigmoid and coronal gyri is explained. Projections to the intermediate zone of the spinal cord are the indirect cortico-motoneuronal fibers to the spinal cord. They terminate mainly in its dorsolateral part. In some of these cases, the fibers to the upper cervical cord were approximately the same in amount as those to the lower cervical cord, while in the others, the latter were considerably less than the former. It is demonstrated that bilateral lesions in the dorsolateral part of the midbrain tegmentum resulted in much reduction, or abolition, of diffuse or reciprocal muscle spindle responses produced by VL stimulation. It is observed that the projection pattern of the sigmoid and coronal gyri to the basal part of the posterior horn was similar to that of the nucleus cornucommissuralis posterior.