Faculty of Science - Mahidol University

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from all stations showed the same in the following characteristics:
fatty change in liver cells which caused pale-yellowed liver, vacuolar
degeneration, couldy swelling, accumulation of yellow-brown
granules in cytoplasm, necrosis of liver cells together with central
veins and hepatic bile ducts, including hepatic bile duct hyperplasia.
In kidney tissue, degeneration of glomeruli, hyaline degeneration
and necrosis of proximal epithelium, and hyperplasia of renal
segments were noticed. The histopathological changes found in
both tissues revealed the damages from toxicants accumulated in
fish. In spleens, they were found hemorrharage and necrotic
erythrocytes which the hemorrhages showed the increase
reproducible of erythrocytes. The more severe of all changes in fish
were observed in summer from Nakorn Phanom and Nongkhai
Provinces, Chaing Rai, Ubonratchathani and Leoi Provinces,
respectively. In winter, fish from Chaing Rai Province were showed
more severe while the others showed the same level of changes.
These changes may be caused by toxicants accumulated in benthose
or toxins from fish pellets.
(The Proceeding of 4 th National Environmental Conference, 19-21
Janm 2005, the Ambassador City, Cholburi, Thailand.)
SOCIAL ISOLATION ALTERS THE EFFECTS
OF ETANOL IN THE RAT SOCIAL INTERACTION
TEST (NO. 851)
Noppamars Wongwitdecha, Benja Ngamnawakul, Haruthai
Thaidee, Sompop Soo-ampon
Department of Pharmacology, Institute of Science and
Technology for Research and Development, Mahidol University,
Thailand.
Social isolation rearing from weaning has been reported to
change the behaviors of the adult animals and modify the
responsibility to many addictive drugs. However, there is no report
concerning the effect of social isolation on the behavioral effect of
ethanol in the social interaction test.
Objective: The aim of the present experiments was to
investigate the effect social isolation on the behavioral effect of
ethanol in the rat social interaction test.
Methods: Male Wistar rats were reared from weaning either
singly (isolation rearing) or in groups of five-six rats/cage (social
rearing). Four weeks later, these rats were tested for their sensitivity
to ethanol using the social interaction test.
Results: In the rat social interaction test, the active social
interaction behavior of the saline-treated isolation reared rats was
not significantly difference from the socially reared controls.
However, the latencies of active social interaction of the salinetreated
isolation reared rats were significantly longer than the social
reared rats (P