Bocian R, Konopacki J
Department of Neurobiology, University of Łódź, 66 Rewolucji 1906 r. St., 90-222 Łódź, Poland.
Acta Neurobiol Exp (Wars). 2001;61(2):125-34. doi: 10.55782/ane-2001-1393.
Earlier in vivo studies conducted on freely moving and anesthetized rats demonstrated that the posterior hypothalamus (PH) comprises pathways critical for producing the synchronous hippocampal formation (HPC) theta rhythm. In addition, these findings suggested that the frequency of the HPC theta was encoded in the PH and then was fed via the medial forebrain bundle to the medial septum and HPC. In the present study we attempted to verify this hypothesis with use of a different in vivo model--freely moving cats. The microinjection of the local anaesthetic, procaine, into the PH region reversibly suppressed the spontaneous as well as sensory and electrically induced HPC theta. However, in contrast to rats, in freely moving cats microinjection of procaine into the PH reduced the amplitude of the HPC theta but had no effect on theta frequency. We conclude that in freely moving cats the PH region comprises a critical part of the ascending brainstem pathway, for production of the HPC theta rhythm. In contrast to rats, in freely moving cats ascending inputs from the brainstem to the PH contribute mainly to the amplitude of the HPC theta rhythm.
早期对自由活动和麻醉大鼠进行的体内研究表明，下丘脑后部（PH）包含对产生海马结构（HPC）同步θ节律至关重要的通路。此外，这些研究结果表明，HPCθ节律的频率在PH中编码，然后通过内侧前脑束传递到内侧隔区和HPC。在本研究中，我们试图使用不同的体内模型——自由活动的猫来验证这一假设。向PH区域微量注射局部麻醉剂普鲁卡因可可逆地抑制自发以及感觉和电诱导的HPCθ节律。然而，与大鼠不同的是，在自由活动的猫中，向PH区域微量注射普鲁卡因会降低HPCθ节律的振幅，但对θ频率没有影响。我们得出结论，在自由活动的猫中，PH区域是产生HPCθ节律的脑干上行通路的关键部分。与大鼠不同的是，在自由活动的猫中，从脑干到PH的上行输入主要影响HPCθ节律的振幅。
