Associational and commissural collaterals of neurons in the hippocampal formation (Hilus fasciae dentatae and subfield CA3)

Laurberg, Søren; Sørensen, Kasper

doi:10.1016/0006-8993(81)90463-7

Cited by 204 publications

(84 citation statements)

References 22 publications

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“…Stimulation of the contralateral PP generates a polysynaptic EPSP (approx. 9-10 ms delay) with a current sink in the inner third of the molecular layer (figure 3b), in good agreement with previous reports [99,100] and the known anatomy of the commissural projection of the MCs [54,101,102]. Using this preparation, we followed the electrophysiological consequences of unilateral LTP induction as a measure of commissural communication.…”

Section: Resultssupporting

confidence: 89%

Functional MRI of long-term potentiation: imaging network plasticity

Álvarez-Salvado

Pallarés

Moreno

et al. 2014

Phil. Trans. R. Soc. B

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Neurons are able to express long-lasting and activity-dependent modulations of their synapses. This plastic property supports memory and conveys an extraordinary adaptive value, because it allows an individual to learn from, and respond to, changes in the environment. Molecular and physiological changes at the cellular level as well as network interactions are required in order to encode a pattern of synaptic activity into a longterm memory. While the cellular mechanisms linking synaptic plasticity to memory have been intensively studied, those regulating network interactions have received less attention. Combining high-resolution fMRI and in vivo electrophysiology in rats, we have previously reported a functional remodelling of long-range hippocampal networks induced by long-term potentiation (LTP) of synaptic plasticity in the perforant pathway. Here, we present new results demonstrating an increased bilateral coupling in the hippocampus specifically supported by the mossy cell commissural/ associational pathway in response to LTP. This fMRI-measured increase in bilateral connectivity is accompanied by potentiation of the corresponding polysynaptically evoked commissural potential in the contralateral dentate gyrus and depression of the inactive convergent commissural pathway to the ipsilateral dentate. We review these and previous findings in the broader context of memory consolidation.

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Section: Resultssupporting

confidence: 89%

Functional MRI of long-term potentiation: imaging network plasticity

Álvarez-Salvado

Pallarés

Moreno

et al. 2014

Phil. Trans. R. Soc. B

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“…2) receives a projection that originates exclusively from neurons in the polymorphic layer (Laurberg and Sorensen, 1981;Frotscher et al, 1991;Buckmaster et al, 1992Buckmaster et al, ,1996. Since, in the rat, this projection originates both in the ipsilateral and contralateral sides of the dentate gyrus, it has been called the associational/ commissural projection.…”

Section: Mossy Cell Projectionsmentioning

confidence: 99%

The dentate gyrus: fundamental neuroanatomical organization (dentate gyrus for dummies)

Amaral

Scharfman

Lavenex

2007

Progress in Brain Research

716

690

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The dentate gyrus is a simple cortical region that is an integral portion of the larger functional brain system called the hippocampal formation. In this review, the fundamental neuroanatomical organization of the dentate gyrus is described, including principal cell types and their connectivity, and a summary of the major extrinsic inputs of the dentate gyrus is provided. Together, this information provides essential information that can serve as an introduction to the dentate gyrusa "dentate gyrus for dummies."

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“…We make use of the finding that CB1Rs are highly expressed in the inner-most third of the molecular layer of the dentate gyrus (Katona et al, 2006;Kawamura et al, 2006;Monory et al, 2006;Tsou et al, 1998). This region, called the supragranular layer (SGL), receives excitatory associational/commissural axonal inputs primarily from hilar mossy cells (Buckmaster et al, 1992;Laurberg and Sorensen, 1981;Scharfman, 1995;Witter and Amaral, 2004). We recorded excitatory synaptic responses in DGCs while stimulating the mossy cell fibers (MCFs), the medial perforant path (MPP), or the lateral perforant path (LPP).…”

Section: Introductionmentioning

confidence: 99%

Input-specific plasticity at excitatory synapses mediated by endocannabinoids in the dentate gyrus

Chiu

Castillo

2008

Neuropharmacology

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SummaryEndocannabinoids (eCBs) mediate transient and long-lasting synaptic plasticity in several brain structures. In the dentate gyrus, activation of the type 1 cannabinoid receptor (CB1R) by exogenous ligands reportedly depresses excitatory synaptic transmission. However, direct evidence of eCB signaling at excitatory synapses in this region has been lacking. Here, we demonstrate that eCB release can be induced by a brief postsynaptic depolarization of dentate granule cells (DGCs), which potently and transiently suppresses glutamatergic inputs from mossy cell interneurons (MCs) but not from entorhinal cortex via the lateral and medial perforant paths. This input-specific depolarizationinduced suppression of excitation (DSE) is calcium-dependent and can be modulated by agonists of cholinergic and group I metabotropic glutamate receptors. Inhibiting the synthesis of 2-arachidonoyl glycerol (2-AG), one of the most abundant eCBs in the brain, by diacyglycerol lipase (DGL) does not abolish DSE. Moreover, preventing the breakdown of anandamide, the other main eCB, does not potentiate DSE. Thus, eCB signaling underlying DSE in the dentate does not require DGL activity and is unlikely to be mediated by anandamide. Finally, we find that manipulations known to induce eCB-LTD at other central synapses do not trigger LTD at MCF-DGC synapses.

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Associational and commissural collaterals of neurons in the hippocampal formation (Hilus fasciae dentatae and subfield CA3)

Cited by 204 publications

References 22 publications

Functional MRI of long-term potentiation: imaging network plasticity

Functional MRI of long-term potentiation: imaging network plasticity

The dentate gyrus: fundamental neuroanatomical organization (dentate gyrus for dummies)

Input-specific plasticity at excitatory synapses mediated by endocannabinoids in the dentate gyrus

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