Styrene Impairs Serial Spatial Reversal Learning in Rats

1994 ◽  
Vol 13 (4) ◽  
pp. 279-300 ◽  
Author(s):  
Philip J. Bushnell
Keyword(s):  
Total Dose ◽  
Reversal Learning ◽  
Positive Response ◽  
Corn Oil ◽  
Behavioral Effect ◽  
Food Delivery ◽  
Reversal Training ◽  
Factors Affecting ◽  
Styrene Exposure ◽  
Serial Reversal

To evaluate the effects of styrene exposure on learning, adult male Long-Evans rats learned repeated reversals of a spatial discrimination task. Styrene monomer (50% vol/vol in corn oil) was administered by gavage to groups of eight rats at 500 mg/kg/day, 5 days/week, for 8 weeks in Experiments (Exps) I and II (total dose = 20.0 g/kg) or for 1,3,5, or 8 weeks in Exp III (total dose = 2.5, 7.5, 12.5, or 20.0 g/kg). Control rats received corn oil vehicle for 8 weeks. Reversal training began 8 (Exp I), 10 (Exp II), or 32 (Exp III) weeks after termination of dosing. In Exp I, an instrumental (IN) schedule was used, under which rats received food after each presentation of a “positive” response lever (S+ ) only if they had made at least one response during that presentation of S+. In Exps II and III, an automaintenance (AU) schedule was used, under which rats received food after every presentation of S+, regardless of responding. In all experiments, a second manipulandum (S°) was presented randomly in time with respect to S + and food delivery. A discrimination ratio (DR) was calculated as the proportion of total responses on S+ in each block of 10 trials. A reversal involved switching the reward values of S+ and S°. Serial reversal learning was quantified in terms of trials to criterion. Reversal learning improved similarly in control and treated rats trained under the IN schedule, whereas treated rats trained under the AU schedule failed to improve as much as controls. Reversal learning of some styrene-treated AU rats in Exp III continued to be impaired for > 1 year after treatment. Increased responding on S° featured prominently in the behavioral effect of styrene. An IN schedule requiring suppression of S° responses for food in Exp III revealed a clear deficit in rats exposed to styrene. Not all treated rats were affected by styrene; nevertheless, changes in the affected individuals were as large as those previously observed after trimethyltin-induced lesions of the CNS. The incidence of impairment was not related to the total dose of styrene given, suggesting the action of other, undetermined factors affecting individual sensitivity to styrene.

scholarly journals Selective Role of the Putamen in Serial Reversal Learning in the Marmoset

2018 ◽  
Vol 29 (1) ◽  
pp. 447-460 ◽  
Author(s):  
Stacey A W Jackson ◽  
Nicole K Horst ◽  
Sebastian F A Axelsson ◽  
Naotaka Horiguchi ◽  
Gemma J Cockcroft ◽  
...  
Keyword(s):  
Reversal Learning ◽  
Serial Reversal

Serial reversal learning of position discrimination in developing rats

2005 ◽  
Vol 48 (1) ◽  
pp. 79-94 ◽  
Author(s):  
Deborah J. Watson ◽  
Jesse R. Sullivan ◽  
Julie G. Frank ◽  
Mark E. Stanton
Keyword(s):  
Reversal Learning ◽  
Position Discrimination ◽  
Serial Reversal

scholarly journals Nutritional and environmental factors affecting plasma ghrelin and leptin levels in rats

2010 ◽  
Vol 207 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Keiko Nakahara ◽  
Rieko Okame ◽  
Tetsuro Katayama ◽  
Mikiya Miyazato ◽  
Kenji Kangawa ◽  
...  
Keyword(s):  
Corn Starch ◽  
Corn Oil ◽  
Cell Number ◽  
Factors Affecting ◽  
Glucose Levels ◽  
Chronic Infusion ◽  
Acyl Ghrelin ◽  
Plasma Leptin ◽  
Ghrelin Secretion ◽  
Intact Rats

We examined which factors suppress the rise of ghrelin secretion under hunger in 16-h-starved rats, and compared the responses of plasma ghrelin and leptin levels to various exogenous and endogenous stimuli in intact rats. Although an acute expansion of the stomach by infusion of 6 ml air or 3 ml water in rats starved for 16 h did not change the level of plasma acyl-ghrelin 3 ml corn starch solution, corn oil, or 20% ethanol significantly decreased it. Vagotomy inhibited suppression by nutrients but not by ethanol. Chronic infusion of ethanol into the stomach for 3 weeks in free-feeding rats caused widespread injury of the stomach mucosa, and increased both plasma ghrelin levels and the number of ghrelin cells. In intact rats, low temperature did not change ghrelin levels, but increased leptin levels. On the other hand, restriction stress decreased plasma ghrelin levels, but had the reverse effect on plasma leptin levels. Although insulin decreased and 20% glucose increased plasma glucose levels, they both decreased plasma ghrelin levels. Insulin elevated plasma leptin levels, but glucose had no effect. These results indicate that 1) acyl-ghrelin secretion from the stomach under fasting condition is suppressed by nutrients but not by mechanical expansion of the stomach; 2) high and low environmental temperature, stress, or administration of insulin reciprocally affect plasma levels of ghrelin and leptin; and 3) an increase of stomach ghrelin cell number and plasma ghrelin levels after chronic ethanol treatment may be involved in restoration of gastric mucosae.

Impairment of olfactory, auditory, and spatial serial reversal learning in rats recovered from pyrithiamine-induced thiamine deficiency.

1991 ◽  
Vol 105 (3) ◽  
pp. 360-374 ◽  
Author(s):  
Robert G. Mair ◽  
Russell L. Knoth ◽  
Sharon A. Rabchenuk ◽  
Philip J. Langlais
Keyword(s):  
Reversal Learning ◽  
Thiamine Deficiency ◽  
Serial Reversal

Factors affecting the risk of brain metastases after chemoradiotherapy for locally advanced non-small-cell lung cancer (LA-NSCLC)

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 17019-17019
Author(s):  
M. Fujii ◽  
Y. Segawa ◽  
N. Nogami ◽  
Y. Hamamoto ◽  
M. Kataoka ◽  
...  
Keyword(s):  
Brain Metastases ◽  
Total Dose ◽  
Survival Time ◽  
Locally Advanced ◽  
Cumulative Risk ◽  
Disease Free Survival ◽  
Cranial Irradiation ◽  
Prophylactic Cranial Irradiation ◽  
Stage Iiia ◽  
Factors Affecting

17019 Background: With an improvement in treatment outcome in patients with LA-NSCLC undergoing radical chemoradiotherapy, brain metastasis has become a greater problem. We assessed the cumulative incidence of brain metastases and its risk factors in such patients with LA-NSCLC. Methods: Between 1993 and 2003, 85 consecutive patients with stage IIIA or IIIB NSCLC underwent chemoradiotherapy in our institution. The characteristics of these patients were as follows: median age, 64 years (range, 39 to 74 years); stage IIIA/IIIB, 30/55 patients; squamous-cell/nonsquamous-cell histologies, 39/46 patients. Concurrent and sequential chemoradiotherapy were administered for 78 and 7 patients, respectively. Only two patients underwent surgical resection after chemoradiotherapy. Fifty-seven patients received conventional thoracic radiotherapy with a total dose of 59.5 ± 1.4 Gy (range, 40 to 70 Gy), and 28 received twice-daily radiotherapy with a total dose of 71.5 ± 6.5 Gy (range, 43 to 86 Gy). Thirty-eight patients received a combination chemotherapy consisting of cisplatin and docetaxel, and the remaining 47 received the other platinum-based regimens. Results: At a median follow-up time of 51 months (range, 9 to 131 months), median survival time was 25 months, with a 3-year survival rate of 36.9%. The median disease-free survival time was 13 months. During treatment and observation periods, 21 (24.7%) patients had developed brain metastases. Thirteen (15.3%) patients experienced brain metastases as the first site of relapse, and in nine (10.6%), brain was the sole site of relapse. The cumulative risk of brain metastases was 15.4% at 1-year, 21.1% at 2-year, and 25.7% at 3-year, respectively. In a multivariate analysis using Cox proportional hazard model, T-factor (T4 vs. T1–3) was the most predictive of brain failure (hazard ratio, 3.51; 95% confidence interval, 1.35 to 9.13; p = 0.01). Conclusions: In patients with LA-NSCLC undergoing chemoradiotherapy, brain was one of the most common sites of failure when locoregional control was achieved. Although efficacy of prophylactic cranial irradiation (PCI) on survival remains unclear for such patients with NSCLC, identification of patients more likely to have a benefit from PCI would be useful. No significant financial relationships to disclose.

A Study of the Carcinogenicity of Glycidol in Syrian Hamsters

1992 ◽  
Vol 8 (5) ◽  
pp. 267-271 ◽  
Author(s):  
William Lijinsky ◽  
Robert M. Kovatch
Keyword(s):  
Ethyl Acetate ◽  
Total Dose ◽  
Adrenal Cortex ◽  
Corn Oil ◽  
Target Organ ◽  
Syrian Hamsters ◽  
Golden Hamsters ◽  
Industrial Chemical ◽  
Syrian Golden Hamsters

The industrial chemical glycidol is a directly acting mutagen and a broadly acting carcinogen in rats. It was administered to Syrian golden hamsters (20 male and 20 female) by gavage of 12 mg twice a week for 60 weeks. The total dose per animal was 1.45 g or 20 mmol. Survival was not different from control hamsters treated with corn oil/ethyl acetate. Of the treated males, 9 had tumors and 13 of the treated females had tumors, some of which were adrenal cortex tumors seen in controls. More tumors were seen in the glycidol-treated hamsters than in controls, but the spleen was the only notable target organ and the number of animals with spleen hemangiosarcomas was small. Glycidol appeared to be less carcinogenic in hamsters than in rats or mice.

scholarly journals PENINGKATAN PRODUKSI DAN KUALITAS TELUR INDUK BANDENG (Chanos chanos) DENGAN PENAMBAHAN BAHAN PENGKAYA PADA PAKAN

2018 ◽  
Vol 13 (1) ◽  
pp. 11
Author(s):  
Muhammad Marzuqi ◽  
Retno Andamari ◽  
Ni Wayan Widia Astuti ◽  
Wawan Andriyanto ◽  
Nyoman Adiasmara Giri
Keyword(s):  
Vitamin E ◽  
Vitamin C ◽  
Fish Oil ◽  
Egg Production ◽  
Egg Quality ◽  
Corn Oil ◽  
Feeding Frequency ◽  
Chanos Chanos ◽  
Factors Affecting ◽  
Spawning Frequency

Pakan merupakan salah satu faktor yang berpengaruh terhadap performa reproduksi induk ikan bandeng. Ketersediaan pelet komersial yang spesifik untuk pemeliharaan induk bandeng hingga kini belum ada sehingga perlu dilakukan pengembangan pakan untuk menghasilkan performa reproduksi yang lebih baik. Penelitian ini bertujuan untuk meningkatkan produksi dan kualitas telur induk bandeng melalui aplikasi bahan pengkaya pada pakan. Penelitian dilakukan di unit pembenihan skala lengkap Desa Banyupoh dan Desa Sanggalangit, Bali Utara. Jumlah induk yang digunakan adalah 165 ekor yang dipelihara dalam dua buah bak volume 100 m3 (di Desa Banyupoh) dan 100 ekor yang dipelihara dalam dua buah bak volume 100 m3 (di Desa Sanggalangit). Perlakuan yang digunakan adalah pakan komersial dengan penambahan bahan pengkaya (pakan uji) dan tanpa penambahan bahan pengkaya pakan (pakan kontrol). Bahan pengkaya berupa emulsi yang terdiri atas lesitin, minyak cumi, minyak ikan, minyak jagung, vitamin E, dan vitamin C yang dicampur dalam pakan dengan dosis sebesar 120 g/kg pakan. Pakan diberikan secara at-satiation dengan frekuensi 2-3 kali sehari. Penelitian berlangsung selama 10 bulan. Parameter yang diamati meliputi frekuensi pemijahan, produksi, dan kualitas telur. Hasil penelitian menunjukkan bahwa penggunaan bahan pengkaya dalam pakan mampu meningkatkan frekuensi pemijahan induk dengan rerata sebanyak lima kali/bulan di unit pembenihan skala lengkap Desa Banyupoh dan empat kali/bulan di unit pembenihan skala lengkap Desa Sanggalangit, serta dapat meningkatkan produksi telur masing-masing sebesar 102% dan 56% dibandingkan pakan kontrol. Teknik penambahan bahan pengkaya pada pakan dapat diterapkan pada pemeliharaan induk bandeng untuk mendukung produksi telur dan frekuensi pemijahan yang baik.Feed is one of the factors affecting the reproduction performance of milkfish broodstock. Hatcheries use mostly commercial pellets to feed broodstock despite that it is not a natural feed for milkfish. Thus, the food has to be enriched to maintain or improve the spawning performance of milkfish broodstock. The purpose of this study was to improve spawning performance of milkfish broodstock through the application of enriched-formulation feed. The study was conducted at two milkfish hatcheries in Banyupoh and Sanggalangit villages, North Bali. The number of broodstock used at Banyupoh village hatchery were 165 ind reared in two 100 m3concrete tanks. In the hatchery at Sanggalangit Village, 100 fish were reared in two 100 m3 concrete tanks. The feed enrichment formulation used a mixture of lecithin, squid oil, fish oil, corn oil, vitamin E, and vitamin C. The feed enrichment formulation was prepared in emulsion form and mixed with 120 g/kg dosage of feed. As a control, the feed used was without enrichment formulation. The feeding frequency was 2-3 times per day to satiation. The experiment was carried out for 10 months. The parameters observed included egg production, egg quality and spawning frequency. The results showed that the enriched feed had increased the spawning frequency of broodstock up to five times/month at the hatchery in Banyupoh and four times/month at Sanggalangit hatchery. Egg production also had increased to 102% (Banyupoh) and 56% (Sanggalangit) compared to the control feed. This feed enrichment formulation has the potential in broodstock milkfish rearing to improve the egg production and spawning frequency.

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