Increase in telencephalic dopamine and cerebellar norepinephrine contents by hydrostatic pressure in goldfish: the possible involvement in hydrostatic pressure-related locomotion
Fish are faced with a wide range of hydrostatic pressure (HP) in their natural habitats. Additionally, freshwater fish are occasionally exposed to rapid changes in HP due to heavy rainfall, flood and/or dam release. Accordingly, variations in HP are one of the most important environmental cues for fish. However, little information is available on how HP information is perceived and transmitted in the central nervous system of fish. The present study examined the effect of HP (water depth of 1.3 m) on the quantities of monoamines and their metabolites in the telencephalon, optic tectum, diencephalon, cerebellum (including partial mesencephalon) and vagal lobe (including medulla oblongata) of the goldfish, Carassius auratus, using high-performance liquid chromatography. HP affected monoamine and metabolite contents in restricted brain regions, including the telencephalon, cerebellum and vagal lobe. In particular, HP significantly increased the levels of dopamine (DA) in the telencephalon at 15 min and that of norepinephrine (NE) in the cerebellum at 30 min. In addition, HP also significantly increased locomotor activity at 15 and 30 min after HP treatment. It is possible that HP indirectly induces locomotion in goldfish via telencephalic DA and cerebellar NE neuronal activity.
KeywordsBrain Fish Hydrostatic pressure Monoamine Swimming
We would like to thank Ms. Chihiro Yamauchi, University of the Ryukyus, and Dr. Yoriko Akimoto, Mr. Takahiro Nakashita, Mr. Seiya Mochinaga and Mr. Takeshi Yoshihara, Kyushu University, for their support and help in sampling. Dr. Sethu Selvaraj, Kyushu University, Dr. Takeshi Onuma, Osaka University, and Mr. Makoto Yoshida, The University of Tokyo, provided stimulating discussions and helpful advice. This study was supported by a Grant-in-Aid for JSPS fellows (Grant Numbers 10J02886 and 12J02083) to TI from the Japan Society for the Promotion of Science.
- Block BA, Booth D, Carey FG (1992) Direct measurement of swimming speeds and depth of blue marlin. J Exp Biol 166:267–284Google Scholar
- Fremberg M, van Veen T, Hartwig HG (1977) Formaldehyde-induced fluorescence in the telencephalon and diencephalon of the eel (Anguilla anguilla l.). A fluorescence-microscopic and microspectrofluorometric investigation with special reference to the innervation of the pituitary. Cell Tissue Res 176:1–22CrossRefPubMedGoogle Scholar
- Kapsimali M, Vidal B, Gonzalez A, Dufour S, Vernier P (2000) Distribution of the mRNA encoding the four dopamine D1 receptor subtypes in the brain of the european eel (Anguilla anguilla): comparative approach to the function of D1 receptors in vertebrates. J Comp Neurol 419:320–343CrossRefPubMedGoogle Scholar
- Sébert ME, Weltzien FA, Moisan C, Pasqualini C, Dufour S (2008) Dopaminergic systems in the European eel: characterization, brain distribution, and potential role in migration and reproduction. In: Dufour S, Prévost E, Rochard E, Williot P (eds) Fish and diadromy in Europe (ecology, management, conservation). Springer, Netherlands, pp 27–46CrossRefGoogle Scholar
- Takemura A, Shibata Y, Takeuchi Y, Hur SP, Sugama N, Badruzzaman M (2012) Effects of hydrostatic pressure on monoaminergic activity in the brain of a tropical wrasse, Halicoeres trimaculatus: possible implication for controlling tidal-related reproductive activity. Gen Comp Endocrinol 175:173–179CrossRefPubMedGoogle Scholar