Dendritic Spine Density and LTP Induction in Cultured Hippocampal Slices

Collin, Carlos; Miyaguchi, Katsuyuki; Segal, Menahem

doi:10.1152/jn.1997.77.3.1614

Cited by 113 publications

(78 citation statements)

References 33 publications

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“…Ref. 63) we found that spine density was lower in our organotypic hippocampal slice cultures after 5-6 DIV as compared with perfused mouse brain at 2, 4, and 8 weeks of age by a factor of 4 -5. This low spine density is likely at least in part due to differences in the actual developmental stages of organotypic slice cultures versus in vivo as it increases strongly after 3-4 weeks in culture (63).…”

Section: Ratio Of Ampar-epsc To Nmdar-epsc Is Increased In Young D36supporting

confidence: 51%

“…63) we found that spine density was lower in our organotypic hippocampal slice cultures after 5-6 DIV as compared with perfused mouse brain at 2, 4, and 8 weeks of age by a factor of 4 -5. This low spine density is likely at least in part due to differences in the actual developmental stages of organotypic slice cultures versus in vivo as it increases strongly after 3-4 weeks in culture (63). This observation also illustrates the importance of the analysis of spine density in perfused brain, which reflects the actual in vivo situation, and of the analysis of synaptic transmission in acute hippocampal slices, as described above.…”

Section: Ratio Of Ampar-epsc To Nmdar-epsc Is Increased In Young D36mentioning

confidence: 49%

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A Kinase Anchor Protein 150 (AKAP150)-associated Protein Kinase A Limits Dendritic Spine Density

Lü

Zha

Kim

et al. 2011

Journal of Biological Chemistry

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The A kinase anchor protein AKAP150 recruits the cAMPdependent protein kinase (PKA) to dendritic spines. Here we show that in AKAP150 (AKAP5) knock-out (KO) mice frequency of miniature excitatory post-synaptic currents (mEPSC) and inhibitory post-synaptic currents (mIPSC) are elevated at 2 weeks and, more modestly, 4 weeks of age in the hippocampal CA1 area versus litter mate WT mice. Linear spine density and ratio of AMPAR to NMDAR EPSC amplitudes were also increased. Amplitude and decay time of mEPSCs, decay time of mIPSCs, and spine size were unaltered. Mice in which the PKA anchoring C-terminal 36 residues of AKAP150 are deleted (D36) showed similar changes. Furthermore, whereas acute stimulation of PKA (2-4 h) increases spine density, prolonged PKA stimulation (48 h) reduces spine density in apical dendrites of CA1 pyramidal neurons in organotypic slice cultures. The data from the AKAP150 mutant mice show that AKAP150-anchored PKA chronically limits the number of spines with functional AMPARs at 2-4 weeks of age. However, synaptic transmission and spine density was normal at 8 weeks in KO and D36 mice. Thus AKAP150-independent mechanisms correct the aberrantly high number of active spines in juvenile AKAP150 KO and D36 mice during development.Dendritic spines receive most of the excitatory input in mammalian neurons (1, 2) and compartmentalize signaling that regulates the synaptic response (3, 4). Several protein kinases and phosphatases, including CaMKII, cAMP-dependent protein kinase (PKA), 3 PKC, and protein phosphatase PP2A and PP2B (calcineurin) (5) play prominent roles in synaptic plasticity. Synaptic activity translates into their activation, thereby affecting spine stability, morphology, and postsynaptic responses (6 -13). Spines are dynamically gained and lost during synaptogenesis (9, 14 -16) and in response to neuronal activity (17-19).AKAP150 is a product of the Akap5 gene in mice and is the main AKAP that recruits PKA to postsynaptic sites (20 -25). It binds with its very C terminus to the N-terminal dimerization domain of the regulatory RII subunits of PKA (26,27). It also binds PKC (28), PP2B (29,30), and the SH3-GK region of the postsynaptic scaffolding proteins SAP97 and PSD-95 (31, 32). PSD-95 binds with its PDZ domains to the C-terminal ((S/ T)X(I/V)) motif of NMDA-type glutamate receptor (NMDAR) NR2 subunits (33). PSD-95 also binds to the C terminus of stargazin (␥2) and its homologues ␥3, ␥4, and ␥8, which associate with AMPAR-type glutamate receptor (AMPAR) for postsynaptic localization in conjunction with . SAP97 directly binds to the AMPAR GluR1 subunit via a PDZ-C-terminal interaction (37) to link AKAP150 and thereby PKA, PKC,. Phosphorylation of GluR1 on Ser-845 by PKA can increase channel activity (42) and accumulation of GluR1-containing AMPAR at the postsynaptic site during hippocampal LTP (43, 44) (see also Refs. 45,46). The N terminus of AKAP150 also binds F-actin, cadherin, adenylyl cyclases, and PIP 2 and targets AKAP150 to dendritic spines and the central region binds PSD-...

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Section: Ratio Of Ampar-epsc To Nmdar-epsc Is Increased In Young D36supporting

confidence: 51%

Section: Ratio Of Ampar-epsc To Nmdar-epsc Is Increased In Young D36mentioning

confidence: 49%

A Kinase Anchor Protein 150 (AKAP150)-associated Protein Kinase A Limits Dendritic Spine Density

Lü

Zha

Kim

et al. 2011

Journal of Biological Chemistry

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“…Semi‐automatic analysis performed with the Filament tracer software revealed that spine density on apical dendrites represented on average 3.21 spines/10 μm (Figure 5b). These values were lower than in another study carried out on 8 to 9‐day‐old rats showing that after 2 and 3 weeks in culture average spine density was 7 and 11 spines/10 μm respectively (Collin, Miyaguchi, & Segal, 1997). This difference may occurs a result of age of the sacrificed neonate rats, which were older in this work, and also to the analysis method used.…”

Section: Discussioncontrasting

confidence: 63%

A new method allowing long‐term potentiation recordings in hippocampal organotypic slices

2017

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BackgroundHippocampal organotypic slices are used to improve the understanding of synaptic plasticity mechanisms because they allow longer term studies compared to acute slices. However, it is more delicate to keep cultures alive in the recording system outside in vitro conditions. Experiments from the organotypic cultures are common but the handling of slices is rarely described in the literature, even though tissue preservation is crucial. Instruments are sometimes required to extract the slices from the culture inserts but this approach is delicate and can lead to damage, given how strongly the slices are attached to the insert.MethodsA new configuration is proposed to secure the transfer of slices from the incubator to the recording chamber through an adaptor piece that can be designed for any model of chamber and/or insert. The adaptor is a Plexiglas ring in which a culture insert containing the slice can be easily introduced and stabilized. This system allows slices to be placed in the interface for electrophysiological investigations without having to detach them from the insert. That way, no damage is caused and the recording system can safely hold the slices, maintaining them close to culture conditions.ResultsIn addition to the description of the adaptation system, slices were characterized. Their viability was validated and microglial expression was observed. According to the experimental conditions, neuroprotective ramified microgliocytes are present. Dendritic spines studies were also performed to determine neuronal network maturity in culture. Moreover, SKF 83822 hydrobromide and three trains of 100 pulses at 100 Hz with a 10‐min inter‐train interval are suggested to induce long‐term potentiation and to record an increase of fEPSP amplitude and slope.ConclusionThis paper provides detailed information on the preparation and characterization of hippocampal organotypic slices, a new recording configuration more suitable for cultures, and a long‐term potentiation protocol combining SKF and trains.

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“…Cdk5 activity is known to regulate the morphogenesis of dendritic spines, the major sites of excitatory synaptic transmission in the CNS, thus influencing the function of neuronal circuits (6,47,48). Under pathological conditions, dendritic spine loss, representing synaptic damage, is known to correlate with the degree of cognitive decline in AD (36)(37)(38).…”

Section: Discussionmentioning

confidence: 99%

S-Nitrosylation activates Cdk5 and contributes to synaptic spine loss induced by β-amyloid peptide

Nakamura

Cao

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

169

182

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The activity of Cdk5 and its regulatory subunit p35 is thought to be important in both normal brain function and neurodegenerative disease pathogenesis. Increased Cdk5 activity, via proteolytic cleavage of p35 to a p25 fragment by the calcium-activated protease calpain or by phosphorylation at Cdk5(Tyr15), can contribute to neurotoxicity. Nonetheless, our knowledge of regulation of Cdk5 activity in disease states is still emerging. Here we demonstrate that Cdk5 is activated by S-nitrosylation or reaction of nitric oxide (NO)-related species with the thiol groups of cysteine residues 83 and 157, to form SNO-Cdk5. We then show that S-nitrosylation of Cdk5 contributes to amyloid-β (Aβ) peptide-induced dendritic spine loss. Furthermore, we observed significant levels of SNO-Cdk5 in postmortem Alzheimer's disease (AD) but not in normal human brains. These findings suggest that S-nitrosylation of Cdk5 is an aberrant regulatory mechanism of enzyme activity that may contribute to the pathogenesis of AD.C dk5 is a cyclin-dependent kinase that is activated by proteins p35, p25, and p39 (1-3). As a predominantly neuronalspecific kinase, Cdk5 lacks a role in cell-cycle control but has been implicated in an array of neuronal functions, including cell survival, axon guidance, neuronal migration, and regulation of synaptic spine density (4-6). Dysregulation of Cdk5 activity may play a role in the pathogenesis of stroke and several neurodegenerative disorders, including Alzheimer's disease (AD), amyotrophic lateral sclerosis, Parkinson's disease, and Huntington's disease (7-11). Cdk5 is also hyperactivated in response to oxidative stress, mitochondrial dysfunction, excitotoxicity, amyloid-β (Aβ) exposure, calcium overload, and neuroinflammation, thus contributing to neuronal damage. These neurotoxic stimuli activate calpain, which cleaves the Cdk5 activator p35 (or p39) into p25 (or p29); p25 accumulation thus contributes to Cdk5 activation (12-16). These changes trigger various events associated with neurodegeneration. Although increased Cdk5 activity has been observed in AD brains compared with nondemented control brains, the mechanism remains contentious (17).Similarly, nitric oxide (NO) and related species contribute to a number of neurodegenerative diseases. The major source of NO in neurons is neuronal nitric oxide synthase (NOS1). Excitotoxic stress increases intracellular Ca 2+ , which in turn activates NOS1, thus generating NO. In general, NO can stimulate soluble guanylate cyclase to form cGMP or can S-nitrosylate critical cysteine residues to regulate the activity of multiple target proteins, in some sense akin to phosphorylation. Indeed, S-nitrosylation may explain many cGMP-independent mechanisms of NO action in neurodegenerative diseases (18). Our group has demonstrated that NO contributes to neurodegenerative disorders by redox reaction consisting of S-nitrosylation; in some cases this reaction is followed by further oxidation. Proteins affected in this manner include the gelatinase enzyme matrix metalloprotineas...

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Dendritic Spine Density and LTP Induction in Cultured Hippocampal Slices

Cited by 113 publications

References 33 publications

A Kinase Anchor Protein 150 (AKAP150)-associated Protein Kinase A Limits Dendritic Spine Density

A Kinase Anchor Protein 150 (AKAP150)-associated Protein Kinase A Limits Dendritic Spine Density

A new method allowing long‐term potentiation recordings in hippocampal organotypic slices

S-Nitrosylation activates Cdk5 and contributes to synaptic spine loss induced by β-amyloid peptide

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