Rumsfeld (tinca) Brain Tissue Morphological Observation And Acute Temperature Stress On Brain Fos Protein Expression,

Few environmental factors have a larger influence on animal energetics than temperature, a fact that makes thermoregulation a very important process for survival. There are many studies on the effects of temperature stress, most of the knowledge on thermoregulatory physiology has emerged from studies using mammalian species, particularly rats. However, studies with all vertebrate groups are essential for a more complete understanding of the mechanisms involved in the regulation of body temperature.Behavioral changes in organisms can result from complex alterations at the biochemical and physiological levels of organization. Knowledge of these underlying processes is crucial to understanding the control of behavior and response to stimuli. Organisms can induce cellular change by adapting to stimuli, and mediating repair and regeneration processes through alterations in gene expression. Adaptation to environmental conditions is only possible due to the rapidity and flexibility of neuronal signal transduction, and downstream changes in gene expression.Phoxinus lagowskii Dybowsky belongs to Pisces, Cyprinomorpha, Cyprinomorpha, Leuciscinae, Phoxinus Agassiz. Phoxinus lagowskii Dybowsky is a kind of small fish with strong adaptive ability, very few studies on the biological characeteristic were reported. The characteristics of thermal adaptation of Phoxinus lagowskii Dybowsky, and its tectological characteristics of brain, and effects of thermal stress on expression of Fos protein in the brain of Phoxinus lagowskii Dybowsky were studied in this paper to investigate the relationship between its tectological characteristics of brain and its living environment and to primarily clarify the central neural mechanism of thermal stress on fish.In order to understand characteristics of thermal adaptation of Phoxinus lagowskii Dybowsky, the preferred temperature, critical minimum avoidance temperature and critical maximum avoidance temperature were measured. The results showed that Phoxinus lagowskii Dybowsky had a wide preferred temperature range, the preferred temperature ranged from 20℃to 28℃, the critical minimum avoidance temperature and critical maximum avoidance temperature were 1.3℃and 36.2℃respectively.Tectology of the brain of Phoxinus lagowskii Dybowsky was investigated. As expected, the brain comprises five parts: telencephalon, diencephalon, mesencephalon, cerebellum and myelecephalon. Olfactory lobe has differentiated, which is similar to other cyprinid fish; Telencephalon is ablong in shape, which is an primordial kind; the optic lobe is the biggest, which implies a very good sight since it lives in clear water; cerebellum is well-developed, implying that this species has a very good ability in controlling movement.The animals were divided into three groups in the FOS expression experiment, the heat stress group (35℃, n=6), the cold stress group (15℃, n=6) and the control group (25℃, n=6). Animals were stimulated by hot or cold for 180 minutes, then FOS was examined with immunohistochemical method. The results indicated that both heat stress group and cold stress displayed alterations in neuronal FOS, and also did in the control group. In telencephalon, the thermal stress group displayed significant alternations in FOS expression compared to the control group, so telencephalon may play an important role in thermal stress. There was no significant FOS expression in thermal stress group compared to the control group in optic lobe. In diencephalon, the thermal stress group displayed significant alternations in FOS expression compared to the control group, thus diencephalon is an important nerve centre in regulation of body temperature. The thermal stress group displayed significant alternations in FOS expression compared to the control group in brainstem, therefore, brainstem may also play an important role in thermal stress.