Analysis of recordings of single-unit firing and population activity in the dorsal subiculum of unrestrained, freely moving rats
Analysis of recordings of single-unit firing and population activity in the dorsal subiculum of unrestrained, freely moving rats
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DOI：
10.1152/jn.00723.2002
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发表时间：
2003-08-01
影响因子：
2.5
通讯作者：
O'Mara, SM
中科院分区：
文献类型：
--
作者：
Anderson, MI;O'Mara, SM
我们检测了自由的成年雄性Wistar大鼠的背侧下丘脑神经元的活动，这些大鼠被植入了一个可移动的八电极微驱动器。下丘是主要的海马体结构输出区，在神经生理学上相对较少被研究。我们比较了老鼠在狭小、受限的环境中的下丘脑单位活动和下丘脑EEG，并将神经元活动与动物正在进行的行为联系起来。根据单位的电生理特性，将其分为突发性单位、规律性尖峰单位、theta调制单位和快速尖峰单位。爆发性和规律性放电单位类似于海马CA1区单位，而快速放电单位似乎是中间神经元。爆炸单元的行为是不同的：一些单元定期爆发，而另一些只是偶尔爆发。Theta调制的单位以前没有被描述过；这些单位在所有方面都类似于常规的尖峰单位，除了当同时的EEG记录中存在theta振荡时，它们的放电显著增加。丘脑下部脑电与海马脑电相似，以theta振荡为主的“警觉、运动”行为为主，而无theta振荡的情况下，主要表现为“警觉、静止”和“安静”行为的大幅度不规则活动(LIA)，包括尖锐波。相对较小比例的下丘脑记录(约32%)被锁相到theta；这一比例比下丘脑接受主要输入的区域要小。这种重要的内在节律相对缺乏对下丘脑神经元的夹带，这表明theta可能能够影响下丘脑下和海马区更广泛的信息处理。
We examined neuronal activity in the dorsal subiculum of unrestrained, male adult Wistar rats, which were implanted with a moveable eight-electrode microdrive. The subiculum is the primary hippocampal formation output area and is comparatively uninvestigated neurophysiologically. We compared subicular unit activity and the subicular EEG while rats occupied a small, restricted environment and also correlated neuronal activity with the ongoing behavior of the animal. Units were separated using their electrophysiological characteristics into bursting units, regular spiking units, theta-modulated units, and fast spiking units. The bursting and regular spiking unit classes are similar to hippocampal CA1 units, whereas the fast spiking units appear to be interneurons. Bursting units were variable in their behavior: some units bursted regularly, and others bursted only occasionally. Theta-modulated units have not been described before; these were similar to regular spiking units in all respects except that they increased their firing significantly when theta oscillations were present in the simultaneous EEG record. Subicular EEG was similar to hippocampal EEG, with theta oscillations dominating "alert, moving" behaviors, while large amplitude irregular activity (LIA), which included sharp waves, predominated when theta oscillations were not present, mainly during "alert, still" and "quiet" behaviors. A relatively small proportion of subicular recordings ( approximately 32%) were phase-locked to theta; this is a smaller proportion than in areas from which the subiculum takes major inputs. The relative lack of entrainment of subicular neurons by this important intrinsic rhythm is suggestive of a limit to which theta might be capable of affecting both subicular and hippocampal information processing more generally.