Relaxin-3/INSL7 Regulates the Stress-response System in the Rat Hypothalamus

Relaxin-3 (RLN3) is a neuropeptide belonging to the insulin–relaxin superfamily. RLN3-expressing neurons are predominantly located in the dorsal pons known as the nucleus incertus, and project their axons to the forebrain including the hypothalamus. RLN3 has been suggested to be involved in the stress response. In the present study, we investigated the hypothalamic action of RLN3 in the stress-response system by intracerebroventricular (icv) administration of RLN3. Compared with saline icv injection, 1 nmol icv RLN3 injection induced c-Fos expression in the paraventricular nucleus of the hypothalamus (PVN) at 1 h after administration. Some RLN3-induced c-Fos-positive cells in the PVN were also corticotropin-releasing factor (CRF)-expressing neurons. CRF and c-fos mRNA levels in the PVN were increased at 2 h after RLN3 administration. Plasma adrenocorticotropic hormone (ACTH) levels were also increased after RLN3 administration. These results suggest that RLN3 is able to stimulate the hypothalamopituitary CRF–ACTH system during the acute response.     

Neuronal basis for evaluating selected action in the primate striatum

Humans and animals optimize their behavior by evaluating outcomes of individual actions and predicting how much reward the actions will yield. While the estimated values of actions guide choice behavior, the choices are also governed by other behavioral norms, such as rules and strategies. Values, rules and strategies are represented in neuronal activity, and the striatum is one of the best qualified brain loci where these signals meet. To understand the role of the striatum in value- and strategy-based decision-making, we recorded striatal neurons in macaque monkeys performing a behavioral task in which they searched for a reward target by trial-and-error among three alternatives, earned a reward for a target choice, and then earned additional rewards for choosing the same target. This task allowed us to examine whether and how values of targets and strategy, which were defined as negative-then-search and positive-then-repeat (or win-stay-lose-switch), are represented in the striatum. Large subsets of striatal neurons encoded positive and negative outcome feedbacks of individual decisions and actions. Once monkeys made a choice, signals related to chosen actions, their values and search- or repeat-type actions increased and persisted until the outcome feedback appeared. Subsets of neurons exhibited a tonic increase in activity after the search- and repeat-choices following negative and positive feedback in the last trials as the task strategy monkeys adapted. These activity profiles as a heterogeneous representation of decision variables may underlie a part of the process for reinforcement- and strategy-based evaluation of selected actions in the striatum.     

Hyperexcitability restricted to the lower limb motor system in a patient with stiff-leg syndrome

We report a 29-year-old man who presented with a 2-year history of progressive stiffness and painful spasms limited to the bilateral lower limbs, exaggerated by auditory and tactile stimuli. His deep tendon reflexes were slightly increased in both lower extremities. His plantar response was flexor. His serum and cerebrospinal fluid were negative for anti-glutamic acid decarboxylase antibodies. Electromyography of antagonist muscle pairs in his distal lower limbs revealed a failure of reciprocal inhibition. We used transcranial magnetic stimulation with a paired-pulse paradigm, delivered to the cortical area of the upper and lower limbs, and revealed significantly enhanced facilitation only in the area of his lower limbs, but not that representing his upper limbs. His symptoms were improved substantially by 20mg/day of oral diazepam. To our knowledge this is the first report of a patient with hyperexcitability limited to the lower limb motor system in a patient with stiff-leg syndrome.     

Bioassay technique using seed shrimps for comparative studies regarding the aquatic acute lethality of biodegradable lubricants

To evaluate the environmental load resulting from the spillage of biodegradable lubricants in aquatic systems, a comparative acute lethality test wherein an oil-water interfacial area could be examined was considered. In this study, oleic acid was employed as a model biodegradable lubricant. Measurements of the pH value and dissolved oxygen (DO) level of water during the exposure tests indicate that water degradation depends on the oil-water interfacial area, exposure duration, and water temperature. Furthermore, 72 h acute lethality tests were performed using two types of freshwater ostracods (seed shrimps) as test organisms: the large species Stenocypris hislopi and the small species Cypretta seurati. The longevity of the small species, which was physically more active, was strongly affected by water pollution. During the exposure test, the DO in water was significantly consumed by the degradation of the lubricant floating on it. Water exposed to a lubricant containing copper (Cu) demonstrated strong toxicity even after the recovery of the pH value and DO level by aging. The decrease in the DO level of water and increase in the concentration of metal compounds are dominant factors responsible for the mortality of aquatic organisms.     

Extensive 0-IIc (undifferentiated carcinoma) lesion around a gastric adenoma: a case report

A 73-year-old woman underwent esophagogastroduodenoscopy (EGD) at a local hospital, which revealed a flat elevated lesion, approximately 15 mm in diameter, in the posterior wall of the lower gastric body. At our hospital, a repeat EGD and biopsy led to a diagnosis of moderately dysplastic adenoma. The patient requested endoscopic submucosal dissection (ESD). Histopathology revealed a gastric adenoma with negativity for tumor at the vertical margin; however, the horizontal margin was positive for cancer with an undifferentiated carcinoma surrounding the adenoma. EGD was repeated, and a discolored area was found around the ESD scar. Biopsy revealed an undifferentiated carcinoma. Laparoscopic distal gastrectomy was performed, and postoperative histopathology also revealed an undifferentiated carcinoma (50 mm in diameter) surrounding the ESD scar; this lesion was an undifferentiated adenocarcinoma that was colocalized with and spread out to surround the original adenoma. This case is important for consideration of the pattern of development and progression of superficial spreading gastric cancer.     

Cognitive function in eating disorders and therapeutic approach

We examined brain activation in the presence of eating disorders while processing unpleasant words concerning body images using functional magnetic resonance imaging (fMRI). Anorexia nervosa restricting type (AN-R) and anorexia nervosa binge-eating/ purging type (AN-BP) patients showed significant amygdala activation. Farther, AN-BP and bulimia nervosa (BN) patients showed significant medial prefrontal cortex activation. Next, we conducted short-term integrated group therapy for eating disorders. After treatment, depressive scores of POMS and emotional-oriented coping scores of CISS were significantly decreased, and EAT scores and self-esteem scores of RSES were significantly increased.     

Inhomogeneous distribution of action potential characteristics in the rabbit sino-atrial node revealed by voltage imaging

The sino-atrial node (SAN) is the natural pacemaker of the heart. Mechanisms of the leading pacemaker site generation and dynamic pacemaker shifts in the SAN have been so far studied with an electrophysiological technique, but the detailed spatial distribution of action potential characteristics in the SAN has not been analyzed due to the limited number of simultaneously recorded sites in microelectrode recording. To elucidate the mechanism of leading pacemaker site generation in the SAN, we applied a voltage imaging technique and analyzed the spatial distribution of action potential characteristics in the rabbit SAN. Action potential parameters, i.e., action potential duration at 50% repolarization level, the slope of upstroke, and the slope of the linearly depolarizing early phase of pacemaker activity (phase-4), were calculated from optical signals. Action potential parameter values derived from intracellular recording with a microelectrode and those from optical recording were significantly correlated. The leading pacemaker site occurred in the region of either globally or locally maximum phase-4 slope in 7 of 12 preparations, however, it did not coincide with the region of the early maximum phase-4 slope in the other 5 preparations. Carbenoxolone, a gap junction blocker, changed action potential properties and caused pacemaker shifts. Model simulation, assuming an inhomogeneous distribution of intrinsic properties of SAN cells, reproduced the experimental results. We conclude that the functional structure of the SAN is more inhomogeneous than that dictated by previous models. Besides intrinsic cellular properties, cell-to-cell interaction through gap junctions influences action potential characteristics and leading pacemaker site generation.     

Mucinous breast carcinoma with myoepithelial‐like spindle cells

Appearance of spindle cells has been believed as a benign index of breast cytology. But, we have frequently observed the spindle cells in smears from mucinous carcinoma of the breast. Here, we characterized the biochemical nature of the spindle cells, so as to clarify their identity in cytology. Nineteen cases of breast mucinous carcinoma were used for cytological examination. The spindle cells were located at edges of tumor cell nests and in the backgrounds of cytological specimens. Immunohistological examination revealed that the spindle cells exhibited both immunoreactivity against carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Immunoreactivity against vimentin, cytokeratin, or alpha‐smooth muscle actin was, however, not observed. The mode of distribution of biochemical markers suggests that the positive cells for anti‐CEA antibody and anti‐EMA antibody are tumor cells compressed by mucin, while the vimentin‐positive cells are fibroblasts. We assert that the presence of spindle cells can be a characteristic feature of mucinous carcinoma of the breast. Discrimination of the spindle cells in mucinous carcinoma from myoepithelial cells and naked bipolar nuclei in benign lesions was established here. It should facilitate precise diagnosis of breast cancer. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

Expression of highly polysialylated NCAM in the neocortex and piriform cortex of the developing and the adult rat

Summary The expression of a highly polysialylated form of the neural cell adhesion molecule (NCAM-H) has been investigated in the neocortex and piriform cortex of the developing and the adult rat by using a monoclonal antibody 12E3, which has been found to recognize the polysialic acid portion of NCAM-H. Immunoblot analysis of the cortical homogenates showed that NCAM-H was temporarily expressed during the late embryonic and early postnatal stages. Further, immunohistochemical observations revealed that NCAM-H appeared at embryonic day 13 (E13) in the plexiform primordium in horizontally-oriented cells, probably Cajal-Retzius cells, which are the first neurons to differentiate. During the late embryonic stage, the marginal zone, subplate, and intermediate zone strongly stained, whereas the ventricular zone stained weakly. After birth, the NCAM-H expression was progressively attenuated from a week onwards, and almost vanished in the adult neocortex. In the primordium of the piriform cortex, NCAM-H immunoreactivity also became positive at E13. The time sequences of the NCAM-H expression in these neurons were similar to those of the neurons in the neocortical area. In the piriform cortex, however, the expression remained in a number of neurons in the layer II, which receives a large number of olfactory fibers from the olfactory bulb, where prolonged neurogenesis and construction of neural circuits take place in adulthood. These results suggest that NCAM-H not only plays an important role in the developing rat cortex, but also may be involved in some functions related to reorganization in the adult piriform cortex.