Electrophysiological characteristics of cholinergic and non-cholinergic neurons in the rat medial septum-diagonal band complex

Markram, Henry; Segal, Menahem

doi:10.1016/0006-8993(90)91106-q

Cited by 97 publications

(78 citation statements)

References 10 publications

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“…2C1,C2). These results are consistent with previous findings in rat MS/DB (Griffith and Matthews, 1986;Markram and Segal, 1990;Jones et al, 1999;Alreja et al, 2000;Wu et al, 2000;Sotty et al, 2003). Thus, slow-firing MS/DB neurons are heretofore operationally referred to as cholinergic neurons.…”

Section: Bath Perfusion Of Ngf Increases Firing Of Cholinergic and Nosupporting

confidence: 94%

“…NGF was included in the aCSF used to perfuse slices, thus exposing the entire preparation to the neurotrophin, and the firing rate of MS/DB neurons was compared before, during, and after exposure to NGF. Individual neurons in the MS/DB display different rates of firing (Markram and Segal, 1990;Jones et al, 1999;Sotty et al, 2003), and Figure 1, A and B, illustrates rate-meter records obtained from a slowfiring (0.5 Hz) and fast-firing (7.2 Hz) neuron, respectively.…”

Section: Bath Perfusion Of Ngf Increases Firing Of Cholinergic and Nomentioning

confidence: 99%

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Nerve Growth Factor Rapidly Increases Muscarinic Tone in Mouse Medial Septum/Diagonal Band of Broca

Yeh²

2005

J. Neurosci.

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Nerve growth factor (NGF) has been implicated in maintaining and regulating normal functioning of the septohippocampal pathway. However, many aspects of its physiological actions and the underlying mechanisms await elucidation. In this study, we investigated the effect of acute NGF exposure on neurons in the mouse medial septum/diagonal band of Broca (MS/DB), focusing on the cholinergic neurons and the subpopulation of noncholinergic neurons that were identified to be putatively GABAergic. We report that MS/DB neurons in a thin slice preparation, when exposed to NGF via bath perfusion, rapidly and indiscriminately increased the rate of spontaneous firing in all MS/DB neurons. However, focal application of NGF to individual MS/DB neurons increased spontaneous firing in cholinergic, but not in the noncholinergic, subpopulation. The NGF-induced effect on cholinergic neurons was direct, requiring activation and signaling via TrkA receptors, which were immunohistochemically localized to the cholinergic neurons in the MS/DB. TrkA receptors were absent in putative GABAergic MS/DB neurons, and blockade of TrkA signaling in these and other noncholinergic neurons had no effect on their firing activity after exposure to NGF. Conversely, methyl scopolamine, blocked the increased firing activity of noncholinergic neurons during bath perfusion of NGF. We propose a cell type-specific mode of action for NGF in the MS/DB. The neurotrophin directly enhances cholinergic neuronal activity in the MS/DB through TrkA-mediated signaling, increasing acetylcholine release and, thus, muscarinic tone. This increase in muscarinic tone, in turn, results in heightened firing activity in noncholinergic MS/DB neurons.

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Section: Bath Perfusion Of Ngf Increases Firing Of Cholinergic and Nosupporting

confidence: 94%

Section: Bath Perfusion Of Ngf Increases Firing Of Cholinergic and Nomentioning

confidence: 99%

Nerve Growth Factor Rapidly Increases Muscarinic Tone in Mouse Medial Septum/Diagonal Band of Broca

Yeh²

2005

J. Neurosci.

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“…1a,b). All recorded neurons exhibited the electrophysiological signature that is characteristic of septohippocampal cholinergic neurons, which included presence of inward rectification but lack of a depolarizing sag in response to hyperpolarizing pulses (Griffith and Matthews, 1986;Markram and Segal, 1990;Gorelova and Reiner, 1996). Also, consistent with our published work, none of the 200 neurons recorded responded to muscarine with an excitation.…”

Section: Hcrts Excite Septohippocampal Cholinergic Neuronssupporting

confidence: 86%

Hypocretin/Orexin Innervation and Excitation of Identified Septohippocampal Cholinergic Neurons

Wu¹,

Záborszky²,

Hajszán³

et al. 2004

J. Neurosci.

131

101

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Hypothalamic fibers containing the wake-promoting peptides, hypocretins (Hcrts) or orexins, provide a dense innervation to the medial septum-diagonal band of Broca (MSDB), a sleep-associated brain region that has been suggested to show intense axonal degeneration in canine narcoleptics. The MSDB, via its cholinergic and GABAergic projections to the hippocampus, controls the hippocampal theta rhythm and associated learning and memory functions. Neurons of the MSDB express very high levels of the Hcrt receptor 2, which is mutated in canine narcoleptics. In the present study, we investigated the electrophysiological effects of Hcrt peptides on septohippocampal cholinergic neurons that were identified in living brain slices of the MSDB using a selective fluorescent marker. Hcrt activation of septohippocampal cholinergic neurons was reversible, reproducible, and concentration dependent and mediated via a direct postsynaptic mechanism. Both Hcrt1 and Hcrt2 activated septohippocampal cholinergic neurons with similar EC 50 values. The Hcrt effect was dependent on external Na ϩ , reduced by external Ba 2ϩ , and also reduced in recordings with CsCl-containing electrodes, suggesting a dual underlying ionic mechanism that involved inhibition of a K ϩ current, presumably an inward rectifier, and a Na ϩ -dependent component. The Na ϩ component was dependent on internal Ca 2ϩ , blocked by replacing external Na ϩ with Li ϩ , and also blocked by bath-applied Ni 2ϩ and KB-R7943, suggesting involvement of the Na ϩ -Ca 2ϩ exchanger. Using double-immunolabeling studies at light and ultrastructural levels, we also provide definitive evidence for a hypocretin innervation of cholinergic neurons. Thus Hcrt effects within the septum should increase hippocampal acetylcholine release and thereby promote hippocampal arousal.

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“…For instance, in vivo recordings using the sharp-microelectrode technique demonstrated that a group of MS/DB cells displaying long-duration action potential and long-duration AHP usually fire at slow rates and have been included in the slow firing category (Brazhnik and Fox, 1997). These membrane properties were consistent with putative magnocellular cholinergic neurons previously identified in vitro (Griffith andMatthews, 1986, Markram andSegal, 1990). In vivo rhythmic firing of these slow firing neurons were associated mainly with the positive peak of the dentate gyrus theta rhythm (Brazhnik and Fox, 1997).…”

supporting

confidence: 69%

“…In vivo rhythmic firing of these slow firing neurons were associated mainly with the positive peak of the dentate gyrus theta rhythm (Brazhnik and Fox, 1997). Previous studies led to a general notion that cholinergic MS/DB are homogeneous, exhibiting similar firing behavior as described above (Griffith and Matthews, 1986, Griffith, 1988, Markram and Segal, 1990, Griffith et al, 1991, Brazhnik and Fox, 1997, Brazhnik and Fox, 1999. However, more recent work revealed that some basal forebrain cholinergic neurons do show bursting capabilities (Lee et al, 2005).…”

Section: Published In Final Edited Form Asmentioning

confidence: 72%

Electrophysiological and morphological heterogeneity of slow firing neurons in medial septal/diagonal band complex as revealed by cluster analysis

Garrido-Sanabria¹,

Perez²,

Bañuelos³

et al. 2007

Neuroscience

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Slow firing septal neurons modulate hippocampal and neocortical functions. Electrophysiologically, it is unclear whether slow firing neurons belong to a homogeneous neuronal population. To address this issue, whole-cell patch recordings and neuronal reconstructions were performed on rat brain slices containing the medial septum/diagonal band complex (MS/DB). Slow firing neurons were identified by their low firing rate at threshold (< 5Hz) and lack of time-dependent inward rectification (I h ). Unsupervised cluster analysis was used to investigate whether slow firing neurons could be further classified into different subtypes. The parameters used for the cluster analysis included latency for first spike, slow afterhyperpolarizing potential, maximal frequency and action potential (AP) decay slope. Neurons were grouped into three major subtypes. The majority of neurons (55%) were grouped as cluster I. Cluster II (17% of neurons) exhibited longer latency for generation of the first action potential (246.5±20.1 ms). Cluster III (28% of neurons) exhibited higher maximal firing frequency (25.3±1.7 Hz) when compared to cluster I (12.3±0.9 Hz) and cluster II (11.8±1.1 Hz) neurons. Additionally, cluster III neurons exhibited faster action potentials at suprathreshold. Interestingly, cluster II neurons were frequently located in the medial septum whereas neurons in cluster I and III appeared scattered throughout all MS/DB regions. Sholl's analysis revealed a more complex dendritic arborization in cluster III neurons. Cluster I and II neurons exhibited characteristics of "true" slow firing neurons whereas cluster III neurons exhibited higher frequency firing patterns. Several neurons were labeled with a cholinergic marker, , and cholinergic neurons were found to be distributed among the three clusters. Our findings indicate that slow firing medial septal neurons are heterogeneous and that soma location is an important determinant of their electrophysiological properties. Thus, slow firing neurons from different septal regions have distinct functional properties, most likely related to their diverse connectivity. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeuroscience. Author manuscript; available in PMC 2010 January 22. Published in final edited form as:Neuroscience. (Griffith et al., 1991, Matthews and Lee, 1991, Jones et al., 1999, Morris et al., 1999, Knapp et al., 2000, Henderson et al., 2001, Sotty et al., 2003. Slow firing neurons are characterized by slow firing rates and pronounced slow post-spike afterhyperpolarization potenti...

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Electrophysiological characteristics of cholinergic and non-cholinergic neurons in the rat medial septum-diagonal band complex

Cited by 97 publications

References 10 publications

Nerve Growth Factor Rapidly Increases Muscarinic Tone in Mouse Medial Septum/Diagonal Band of Broca

Nerve Growth Factor Rapidly Increases Muscarinic Tone in Mouse Medial Septum/Diagonal Band of Broca

Hypocretin/Orexin Innervation and Excitation of Identified Septohippocampal Cholinergic Neurons

Electrophysiological and morphological heterogeneity of slow firing neurons in medial septal/diagonal band complex as revealed by cluster analysis

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