57-65
An experimental study on the peripheral autonomic nervepotential in the spinal cord injury model by microneurography
by Taku Ogura,Yasuhiko Kira, Shunzo Aramaki, Fumihiko Nakanishi, Kookho Lee,Toshikazu Kubo

The purpose of the present investigation was to analyze the effects of spinal cord injury (SCI) on the peripheral sympathetic nerve, skin sympathetic activity (SSA), and muscle sympathetic activity (MSA). Todo this sixteen male Japanese white rabbits weighing 1.0 kg-1.5 kg were used. The exposed spinal cord was transected at various levels. Microelectrodes were placed on the muscular branch and on the cutaneous branch, and they were separately induced using a 0.5 -5 kHz amplifier. The data were calculated with the time reset integration value at 60 seconds.Results: It is usually satisfactory to considered that the peripheral sympathetic fibers from T1-3 generally pass up through the sympathetic chain to the upper extremities, and that fibers from T9-11 pass up through the sympathetic chain to the lower limbs. In the electrophysiological properties studied, the SSA could notbe recognized as a spontaneous activity. On the other hand, the MSA could be recognized as a spontaneous regular activity which synchronizes with the R wave of the electrocardiogram. Conclusions: The MSA potentials synchronized with the heart rate, and they seem to correlate with the body homeostasis. The existence of a central regulatory mechanism is suggested from those findings notonly in vital rhythms, such as the heart rate variability but also in the MSA.

67-72
Distribution of mast cells in lung tissues of rats exposed to biomass smoke
by M. Kanter, M. Yörük, B. Özbay, T. Karaca, S. Acar & O. Coskun

This study was designed to evaluate the distribution of mast cells in the lung tissues of rats exposed to biomass smoke. Fifty six female Wistar albino adult rats were used. They were divided into two experimental groups(control and biomass smoke-treated), each containing 28 animals. Control rats were not exposed to the biomass smoke at any time during the experiment. Rats in the treatment group were exposed daily (one hour) to biomass smoke for 3, 6 or 9 months. Lung tissues samples were obtained under deep anesthesia from the randomly selected 7 animals in both groups. Lung tissues were fixed in Mota’s fixative (BLA) for 24 h and embedded in paraffin. Sections of 6 µm thickness were cut and stained with 0.5% toluidine blue in 0.5 N hydrochloric acid at pH 0.5 for 30 min. The numbers of mast cell in lung tissues of the animals exposed tothe biomass for 6 or 9 months were significantly (P<0.05) higher than controls. This study showed that long term exposure to biomass smoke was associated with the increased number of mast cells in the lung.

73-77
Occlusal reduction of unilateral molars influences change of stress-related hormones in rats
by Hwang YK, Chun JS, Yoo PD, Ma JY, Hyun BH, Kim SU, Chang KT & Lee SH

In order to investigate the change of stress-related hormones by dental occlusal reduction, we groundmolars in Sprague-Dawley (SD) rats and evaluated the effect on hormone levels. Thirteen and 18 weeks after occlusal reduction, cortisol concentration was increased 2.75 and 2.17 fold respectively, whereas corticosterone concentration was slightly elevated by 31.2% and 13.5%, respectively. Body weight was slightly decreased, but feed and water intake, and blood chemistry were the same in the experimental group asin the control group. Our results suggest that unilateral molar occlusal reduction may influence cortisol and corticosterone levels and the endocrine system, leading to hormone imbalance through the body.

101-112
Improving unbiased left/right training of rats and use of physostigmine to counteract scopolamine-induced short-termmemory impairment
by Loftur R. Gissurarson, Gunnar M. Karlsson, Sveinbjorn Gizurarson, Kolbrun Hrafnkelsdóttir, Kristbjorg Sigurdardottir & Benedikt G. Ófeigsson.

Rationale: The DNMTP task measures short-term / working memory uncontaminated by learning capacity,spatial abilities, motor performance or general motivational and arousal factors. However, DNMTP training of rats can take two months, and we aimed to reduce this. Methods: Two experiments were conducted on ratsin an operant DNMTP task. Improvements were made on the training procedure. The method was validated by replicating the effect of scopolamine on working memory. The experiments also explored the influence of physostigmine in reversing impairment induced by scopolamine. Thus in experiment 1, ten Lewis rats were trained in an operant DNMTP task (1, 2, 4 and 8 s delay intervals) before 9 of them received vehicle, scopolamine, saline or combinations of scopolamine and physostigmine. In experiment 2, ten Lewis rats (5 old and 5 young) were trained in the same task (1, 2, 4, 8 and 16 s delay intervals). There were six treatments: 0.05 mg/kg scopolamine, 0.1 mg/kg physostigmine or 0.15 mg/kg physostigmine, control involving saline or involving no injection and no handling, and finally a combined treatment of 0.05mg/kg scopolamine and 0.15 mg/kg physostigmine. In both experiments scopolamine significantly reduced correct responses, nose-pokes and lever presses compaired to control conditions. Furthermore, in experiment 2,there was insignificant difference between saline and combined scopolamine/physostigmine for correct responses and for delay prior to pressing the sample lever. As expected, there was significant difference between scopolamine and combined scopolamine/physostigmine for correct responses, for delay prior topressing the sample lever and for delay prior to pressing the non-matching lever. As a result, the animals were ready for drug injection after 17 days from habituation and the method ensured that there were no drop-outs due to left or right lever preference. This is a shorter training period than previously thought necessary.The brief training method was validated by replicating the effect of scopolamine on working memory.

113-115
Hypoglycemic effect of Rheum ribes roots in alloxan induceddiabetic and normal mice
by Hanefi Özbek, Ebubekir Ceylan, Mehmet Kara, Fevzi Özgökce, Mehmet Koyuncu

A decoction extract of Rheum ribes roots was given orally and tested for hypoglycemic effect in healthyand in alloxan-diabetic mice. The results were compared with glibenclamide, a standard hypoglycemic agent, and control groups. It was found that the extract possesses a hypoglycemic effect in diabetic animals.

116
The Ministry of Education and Research's Quality of Education Prize

118
Meetings