The most known function of the intergeniculate leafl et (IGL) is regulation of circadian rhythms by integration of photic and non-photic cues and conveying this signal to the site of main oscillator – suprachiasmatic nuclei. Information about nonphotic cues enter the IGL from various brain nuclei, including those involved in regulation of sleep/wake states. Hypothalamic peptides – orexins has been implicated in numerous physiological functions including maintenance of arousal and wakefulness. Since it has been shown that fi bers containing orexins are distributed in the area of the IGL, the orexinergic system may constitute one of the possible candidate to transmit non-photic/arousal related cues to the IGL. Using the immunohistochemical and electrophysiological recording techniques we evaluated the innervation of the two major types of the IGL neurons by fi bers containing orexin B (OXB) and its infl uence on the activity of the IGL cells. Experiments were performed on brain slices, obtained from adult male Wistar rats, using extracellular single unit recordings. For each individual neuron, after reaching the stable baseline activity, the OXB (1 μM) was applied by local pressure injection. Administered drugs evoke an increase in the fi ring rate of the IGL neurons. Obtained data are in agreement with the results of our immunohistochemical staining revealing the presence of orexin fi bers in the area of the IGL.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.