Perinatal Exposure to Low-Dose Bisphenol A Impairs Spatial Learning and Memory in Male Rats

Bisphenol A (BPA) is an estrogenic endocrine disruptor used for producing polycarbonate plastics and epoxy resins. This study investigated the effects of perinatal BPA exposure on learning and memory, general activity, and emotionality in male Sprague Dawley rats using a battery of behavioral tests, including an appetite-motivated maze test (MAZE test) used to assess spatial learning and memory. Mother rats were orally administered BPA (50 or 500 μg・kg-1/day) or vehicle (1 ml・kg-1/day) from gestational day 10 to postnatal day 14. In the MAZE test, compared to the offspring of vehicle-treated rat mothers, male offspring of mothers exposed to 50 μg・kg-1/day of BPA, but not those of mothers exposed to 500 μg・kg-1/day of BPA, needed significantly more time to reach the reward. Although male offspring of mothers exposed to 50 μg・kg-1/day of BPA showed an increase in a behavioral measure of wariness after repeated testing in the open-field test, no significant effects were observed in locomotor activities. No significant differences were observed in any other behavioral test including the elevated plus-maze test. The present study suggests that perinatal exposure to low-dose BPA specifically and non-monotonically impairs spatial learning and memory in male offspring rats

Gastric cancer with autoimmune gastritis

Background: Autoimmune gastritis is known to be associated with neoplastic lesions but the relationship between autoimmunity and tumorigenesis have not been sufficiently clarified. The aim of this study is to assess the clinicopathological characteristics of gastric cancer cases associated with autoimmune gastritis. Methods: A total of 24 patients diagnosed as early gastric cancer with autoimmune gastritis were registered. Chart reviews with the data including age, gender, state of Helicobacter pylori infection, comorbidity, and concomitant gastric diseases were conducted. As for the characteristics of gastric cancer, location, size, morphological type, histopathology, invasion depth, and the presence of metachronous or simultaneous lesion were assessed. These data from autoimmune gastritis group were compared with those from 301 patients of early gastric cancer as a control group. Results: The gastric cancer associated with autoimmune gastritis was located in the upper, middle, and lower parts in 28.1%, 53.1%, and 18.8%, respectively. The morphological types are as follows: 0-I, 9.4%; 0-IIa, 28.1%; 0-IIb, 15.6%; 0-IIc, 46.9%; and 0-III, 0.0%. The mean tumor size was 21.8 mm. While 90.6% were confined to the mucosa, 9.4% showed submucosal invasion. The histological classifications are as follows: tub1, 50.0%; tub2, 15.6%; pap, 21.9%; sig, 9.4%; and por, 3.1%. More numbers of female, protruded types, larger tumor size, papillary tumor, and that in the upper location were observed in autoimmune gastritis group compared to control group. Conclusion: Early gastric cancer associated with autoimmune gastritis demonstrated different characteristics from those without autoimmune gastritis including variety of tumor morphologies and histological types with female dominancy

Herbivore-Specific, Density-Dependent Induction of Plant Volatiles: Honest or “Cry Wolf” Signals?

Plants release volatile chemicals upon attack by herbivorous arthropods. They do so commonly in a dose-dependent manner: the more herbivores, the more volatiles released. The volatiles attract predatory arthropods and the amount determines the probability of predator response. We show that seedlings of a cabbage variety (Brassica oleracea var. capitata, cv Shikidori) also show such a response to the density of cabbage white (Pieris rapae) larvae and attract more (naive) parasitoids (Cotesia glomerata) when there are more herbivores on the plant. However, when attacked by diamondback moth (Plutella xylostella) larvae, seedlings of the same variety (cv Shikidori) release volatiles, the total amount of which is high and constant and thus independent of caterpillar density, and naive parasitoids (Cotesia vestalis) of diamondback moth larvae fail to discriminate herbivore-rich from herbivore-poor plants. In contrast, seedlings of another cabbage variety of B. oleracea (var. acephala: kale) respond in a dose-dependent manner to the density of diamondback moth larvae and attract more parasitoids when there are more herbivores. Assuming these responses of the cabbage cultivars reflect behaviour of at least some genotypes of wild plants, we provide arguments why the behaviour of kale (B. oleracea var acephala) is best interpreted as an honest signaling strategy and that of cabbage cv Shikidori (B. oleracea var capitata) as a “cry wolf” signaling strategy, implying a conflict of interest between the plant and the enemies of its herbivores: the plant profits from being visited by the herbivore's enemies, but the latter would be better off by visiting other plants with more herbivores. If so, evolutionary theory on alarm signaling predicts consequences of major interest to students of plant protection, tritrophic systems and communication alike

ヨウジ ヲ タイショウ ト シタ カンキョウ キョウイク プログラム ノ ココロミ ―トウキョウ ノウギョウ ダイガク イセハラ ノウジョウ ヲ ジレイ ト シテー

本研究では，東京農業大学農学分野の教員・技術員と幼稚園教諭とが連携し，野菜や果樹栽培の教育研究を活かした環境教育プログラムを試みた。本研究では，プログラムのねらいに応じて伊勢原農場内で教育素材を選定し，環境教育プログラムを実施した。環境教育プログラムでは，ステビア，レモングラス，コキアを五感で体験し植物の用途や効用を学ぶ環境教育プログラムを実施した。加えて，幼児が日常生活で親しんでいる野菜・果樹としてブトウ，ブルーベリー，ミニトマトの栽培技術や品種の違いを学ぶ環境教育プログラムを実施した。本プログラムの教育効果として，伊勢原農場の多様な果樹・野菜とその栽培技術は幼児たちに身近な野菜や果樹への発見，楽しさ，感動を与え，観察した物事を記録できる観察力や理解力の向上を確認できた。In this research, faculty members and technical engineers from Tokyo University of Agriculture have conducted a trial environmental education program in cooperation with the teachers of the Seijo Kindergarten utilizing vegetable and fruit cultivation related educational research. Specifically, the objectives besides holding the actual educational event was to clarify the purpose of the educational program and to select the education materials for future use. As part of the environmental education program, children learned about the uses and effects of the plants Sevia, Lemongrass and Bassia Scoparia using their five senses. In addition, children were able to learn about the different cultivation methods and varieties of everyday vegetables and fruits that they encounter on a daily basis such as grapes, blueberries and cherry tomatoes. As a result of the program children were evidently able to improve their observation skills and comprehension skills by taking notes of their new discoveries, joys and impressions of everyday vegetables, while they learned about the wide varieties of vegetables and fruits of the Isehara Farmland and their cultivation methods. Meanwhile, as for the provision of the Isehara Farmland as a sustainable venue of environmental education, the establishment of an acceptance system and the securing of human resources remain as potential issues

Genistein improves spatial learning and memory in male rats with elevated glucose level during memory consolidation

Cognitive dysfunction due to higher blood glucose level has been reported previously. Genistein (GEN) is a phytoestrogen that we hypothesized might lead to improved memory, despite elevated blood glucose levels at the time of memory consolidation. To investigate this hypothesis, we compared the effects of orally administered GEN on the central nervous system in normal versus glucose-loaded adult male rats. A battery of behavioral assessments was carried out. In the MAZE test, which measured spatial learning and memory, the time of normal rats was shortened by GEN treatment compared to the vehicle group, but only in the early stages of testing. In the glucose-loaded group, GEN treatment improved performance as mazes were advanced. In the open-field test, GEN treatment delayed habituation to the new environment in normal rats, and increased the exploratory behaviors of glucose-loaded rats. There were no significant differences observed for emotionality or fear-motivated learning and memory. Together, these results indicate that GEN treatment improved spatial learning and memory only in the early stages of testing in the normal state, but improved spatial learning and memory when glucose levels increased during memory consolidation

Perinatal exposure to genistein, a soy phytoestrogen, improves spatial learning and memory but impairs passive avoidance learning and memory in offspring

This study investigated the effects of perinatal genistein (GEN) exposure on the central nervous system of rat offspring. Pregnant dams orally received GEN (1 or 10. mg/kg/day) or vehicle (1. ml/kg/day) from gestation day 10 to postnatal day 14. In order to assess the effects of GEN on rat offspring, we used a battery of behavioral tests, including the open-field, elevated plus-maze, MAZE and step-through passive avoidance tests. MAZE test is an appetite-motivation test, and we used this mainly for assessing spatial learning and memory. In the MAZE test, GEN groups exhibited shorter latency from start to goal than the vehicle-treated group in both sexes. On the other hand, performances in the step-through passive avoidance test were non-monotonically inhibited by GEN in both sexes, and a significant difference was observed in low dose of the GEN-treated group compared to the vehicle-treated group in female rats. Furthermore, we found that perinatal exposure to GEN did not significantly alter locomotor activity or emotionality as assessed by the open-field and elevated-plus maze tests. These results suggest that perinatal exposure to GEN improved spatial learning and memory of rat offspring, but impaired their passive avoidance learning and memory

Bisphenol A Does Not Affect Memory Performance in Adult Male Rats

Bisphenol A (BPA) is an estrogenic endocrine disruptor used for producing polycarbonate plastics and epoxy resins. This study investigated the effects of oral BPA administration on memory performance, general activity, and emotionality in adult male Sprague Dawley rats using a battery of behavioral tests, including an appetite-motivated maze test (MAZE test) used to assess spatial memory performance. In addition, in order to confirm the effects of BPA on spatial memory performance, we examined whether intrahippocampal injection of BPA affects spatial memory consolidation. In the MAZE test, although oral BPA administration at 10 mg/kg significantly altered the number of entries into the incorrect area compared to those of vehicle-treated rats, male rats given BPA through either oral administration or intrahippocampal injection failed to show significant differences in latencies to reach the reward. Also, oral BPA administration did not affect fear-motivated memory performance in the step-through passive avoidance test. Oral BPA administration at 0.05 mg/kg, the lowest dose used in this study, was correlated with a decrease in locomotor activity in the open-field test, whereas oral administration at 10 mg/kg, the highest dose used in this study, was correlated with a light anxiolytic effect in the elevated plus-maze test. The present study suggests that BPA in adulthood has little effect on spatial memory performance in male rats

Involvement of Reactive Oxygen Species in the Transforming Capacity of Oncogenic RAS.

41st Annual Meetin