Orexin (hypocretin) - induced hippocampal theta rhythm in urethanized rats

• Autorzy: Bocian R. , Kowalczyk T. , Kazmierska P. , Golebiewski H. , Konopacki J.
• Języki publikacji: EN

Abstrakty

EN

Orexins (OX), also called hypocretins, are bioactive peptides secreted only from neurons located in the lateral hypothalamus. Immunohistochemical studies indicated that OX neurons project diffusely to almost all brain regions. Widespread projection can determinate multifunctional role these neuropeptides. Preliminary investigations indicated that OX neurons are primarily engaged in food intake and body weight regulation but now they are recognized as major regulators of arousal and sleep-architecture. However, to understand what other physiological function are regulated by OX it is necessary to investigate each site of orexins projection. An existence of well defined orexin-immunoreactive fibers and orexin-B receptor-containing cells in the hippocampal formation (HPC) encouraged us to study the role of orexin B (OXB) in production of hippocampal theta rhythm in urethanized rats. Microinjection of OXB (0.2 ug/0.5 ul) into HPC resulted in theta episodes with increased amplitude and power. In contrast to the amplitude and power, theta frequency was not affected. This effect was reversible and lasted about 1.5 hour. In separate experiments the effect of intrahppocampal injection of OXB, after systemic injection of atropine sulphate (the muscarinic receptor blocker, 8 mg/kg), was also examined. Intracerebral administration of OXB in atropine pretreated animals induced again theta oscillations. Results obtained in the present study indicated that the hippocampal orexin-B receptors are actively involved in mechanism responsible for generating theta-band oscillations in anesthetized rats.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2011
• Tom: 71
• Numer: S
• Opis fizyczny: p.51

Twórcy

autor

Bocian R.

• Department of Neurobiology, University of Lodz, Lodz, Poland

autor

Kowalczyk T.

• Department of Neurobiology, University of Lodz, Lodz, Poland

autor

Kazmierska P.

• Department of Neurobiology, University of Lodz, Lodz, Poland

autor

Golebiewski H.

• Department of Neurobiology, University of Lodz, Lodz, Poland

autor

Konopacki J.

• Department of Neurobiology, University of Lodz, Lodz, Poland

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