Gain Modulation of Cholinergic Neurons in the Medial Septum-Diagonal Band of Broca Through Hyperpolarization.
Gain Modulation of Cholinergic Neurons in the Medial Septum-Diagonal Band of Broca Through Hyperpolarization.
复制标题
通过超极化获得布罗卡内侧隔膜对角带中胆碱能神经元的调节。
DOI：
10.1002/hipo.22653
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发表时间：
2016
期刊：
影响因子：
3.5
通讯作者：
Fernandez,FernandoR
中科院分区：
文献类型：
--
作者：
Melonakos,EricD;White,JohnA;Fernandez,FernandoR
Hippocampal network oscillations are important for learning and memory. Theta rhythms are involved in attention, navigation, and memory encoding, whereas sharp wave‐ripple complexes are involved in memory consolidation. Cholinergic neurons in the medial septum‐diagonal band of Broca (MS‐DB) influence both types of hippocampal oscillations, promoting theta rhythms and suppressing sharp wave‐ripples. They also receive frequency‐dependent hyperpolarizing feedback from hippocamposeptal connections, potentially affecting their role as neuromodulators in the septohippocampal circuit. However, little is known about how the integration properties of cholinergic MS‐DB neurons change with hyperpolarization. By potentially altering firing behavior in cholinergic neurons, hyperpolarizing feedback from the hippocampal neurons may, in turn, change hippocampal network activity. To study changes in membrane integration properties in cholinergic neurons in response to hyperpolarizing inputs, we used whole‐cell patch‐clamp recordings targeting genetically labeled, choline acetyltransferase‐positive neurons in mouse brain slices. Hyperpolarization of cholinergic MS‐DB neurons resulted in a long‐lasting decrease in spike firing rate and input‐output gain. Additionally, voltage‐clamp measures implicated a slowly inactivating, 4‐AP‐insensitive, outward K+conductance. Using a conductance‐based model of cholinergic MS‐DB neurons, we show that the ability of this conductance to modulate firing rate and gain depends on the expression of an experimentally verified shallow intrinsic spike frequency‐voltage relationship. Together, these findings point to a means through which negative feedback from hippocampal neurons can influence the role of cholinergic MS‐DB neurons. © 2016 Wiley Periodicals, Inc.
