TY - JOUR
T1 - Photoperiodic responses of depression-like behavior, the brain serotonergic system, and peripheral metabolism in laboratory mice
AU - Otsuka, Tsuyoshi
AU - Kawai, Misato
AU - Togo, Yuki
AU - Goda, Ryosei
AU - Kawase, Takahiro
AU - Matsuo, Haruka
AU - Iwamoto, Ayaka
AU - Nagasawa, Mao
AU - Furuse, Mitsuhiro
AU - Yasuo, Shinobu
N1 - Funding Information:
This study was supported by Grants-in-Aid for Young Scientists (B) to SY (No. 24780286 ) and JSPS Fellows to TO (No. 25.4372 ), and in part by Grants-in-Aid for Scientific Research (A) to MF (No. 23248046 ) from the Japanese Society for the Promotion of Science . This work was also supported by Grant for Basic Science Research Projects from the Sumitomo Foundation and Life Science Research Grant from Takeda Science Foundation to SY. The cost of publication was supported in part by the Research Grant for Young Investigators of Faculty of Agriculture, Kyushu University .
Funding Information:
Funding for this study was provided by the Japanese Society for the Promotion of Science, the Sumitomo Foundation, and the Life Science Research Grant from Takeda Science Foundation. They had no role in study design, data collection and analysis, and decision to write, submit, or publish the paper.
PY - 2014
Y1 - 2014
N2 - Seasonal affective disorder (SAD) is characterized by depression during specific seasons, generally winter. The pathophysiological mechanisms underlying SAD remain elusive due to a limited number of animal models with high availability and validity. Here we show that laboratory C57BL/6J mice display photoperiodic changes in depression-like behavior and brain serotonin content. C57BL/6J mice maintained under short-day conditions, as compared to those under long-day conditions, demonstrated prolonged immobility times in the forced swimming test with lower brain levels of serotonin and its precursor l-tryptophan. Furthermore, photoperiod altered multiple parameters reflective of peripheral metabolism, including the ratio of plasma l-tryptophan to the sum of other large neutral amino acids that compete for transport across the blood-brain barrier, responses of circulating glucose and insulin to glucose load, sucrose intake under restricted feeding condition, and sensitivity of the brain serotonergic system to peripherally administered glucose. These data suggest that the mechanisms underlying SAD involve the brain-peripheral tissue network, and C57BL/6J mice can serve as a powerful tool for investigating the link between seasons and mood.
AB - Seasonal affective disorder (SAD) is characterized by depression during specific seasons, generally winter. The pathophysiological mechanisms underlying SAD remain elusive due to a limited number of animal models with high availability and validity. Here we show that laboratory C57BL/6J mice display photoperiodic changes in depression-like behavior and brain serotonin content. C57BL/6J mice maintained under short-day conditions, as compared to those under long-day conditions, demonstrated prolonged immobility times in the forced swimming test with lower brain levels of serotonin and its precursor l-tryptophan. Furthermore, photoperiod altered multiple parameters reflective of peripheral metabolism, including the ratio of plasma l-tryptophan to the sum of other large neutral amino acids that compete for transport across the blood-brain barrier, responses of circulating glucose and insulin to glucose load, sucrose intake under restricted feeding condition, and sensitivity of the brain serotonergic system to peripherally administered glucose. These data suggest that the mechanisms underlying SAD involve the brain-peripheral tissue network, and C57BL/6J mice can serve as a powerful tool for investigating the link between seasons and mood.
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U2 - 10.1016/j.psyneuen.2013.10.013
DO - 10.1016/j.psyneuen.2013.10.013
M3 - Article
C2 - 24485474
AN - SCOPUS:84893398811
SN - 0306-4530
VL - 40
SP - 37
EP - 47
JO - Psychoneuroendocrinology
JF - Psychoneuroendocrinology
IS - 1
ER -