Phorbol 12, 13-dibutyrate enhances electrically stimulated neuromessenger release from rat dorsal hippocampal slices in vitro

Bilateral interconnections through the hippocampal commissure play important roles in synchronizing or spreading hippocampal seizure activities. Intact hippocampi or bilateral hippocampal slices have been isolated from neonatal or immature rats (6–7 or 12–21 days old, respectively) and the mechanisms underlying the bilateral synchrony of hippocampal epileptiform activities have been investigated. However, the feasibility of examining bilateral epileptiform activities of more developed hippocampal circuitry in vitro remains to be explored. For this, we prepared bilateral hippocampal slices from C57 black mice, a strain commonly used in neuroscience and for genetic/molecular modifications. Young mice (21–24-day-old) were used in most experiments. A 600-μm-thick slice was obtained from each mouse by horizontal vibratome sectioning. Bilateral dorsal hippocampal and connecting dorsal hippocampal commissure (DHC) tissues were preserved in the slice and extrahippocampal tissues were removed. Slices were recorded in a submerged chamber mainly at a room temperature (21–22°C). Bilateral CA3 areas were monitored by extracellular recordings, and unilateral electrical stimulation was used to elicit CA3 synaptic field potentials. The unilateral stimulation could elicit population spikes in the contralateral CA3 area. These contralateral spikes were attenuated by inhibiting synaptic transmission with cobalt-containing medium and were abolished when a cut was made at the DHC. Self-sustained and bilaterally correlated epileptiform potentials were observed following application of 4-aminopyradine and became independent after the DHC cut. Bilateral hippocampal activities were detectable in some slices of adult mice and/or at 35–36°C, but with smaller amplitudes and variable waveforms compared to those observed from slices of young mice and at the room temperature. Together, these observations suggested that examining bilateral epileptiform activities in hippocampal slices of young mice is feasible. The weaknesses and limitations of this preparation and our experimentation are discussed.

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Aluminum Suppresses Effect of Nicotine on Gamma Oscillations (20-40 Hz) in Mouse Hippocampal Slices

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527317666180619155644 ◽

2018 ◽

Vol 17 (6) ◽

pp. 404-411 ◽

Cited By ~ 4

Author(s):

Syeda Mehpara Farhat ◽

Touqeer Ahmed

Keyword(s):

Nicotinic Acetylcholine Receptors ◽

Cholinergic System ◽

Acetylcholine Receptors ◽

Peak Power ◽

Hippocampal Slices ◽

Field Potential ◽

Gamma Oscillations ◽

Gamma Oscillation ◽

Facilitatory Effect

Background: Aluminum (Al) causes neurodegeneration and its toxic effects on cholinergic system in the brain is well documented. However, it is unknown whether and how Al changes oscillation patterns, driven by the cholinergic system, in the hippocampus. Objective: We studied acute effects of Al on nicotinic acetylcholine receptors (nAChRs)-mediated modulation of persistent gamma oscillations in the hippocampus. Method: The field potential recording was done in CA3 area of acute hippocampal slices. Results: Carbachol-induced gamma oscillation peak power increased (1.32±0.09mV2/Hz, P<0.01) in control conditions (without Al) by application of 10µM nicotine as compared to baseline value normalized to 1. This nicotine-induced facilitation of gamma oscillation peak power was found to depend on non-α7 nAChRs. In slices with Al pre-incubation for three to four hours, gamma oscillation peak power was reduced (5.4±1.8mV2/Hz, P<0.05) and facilitatory effect of nicotine on gamma oscillation peak power was blocked as compared to the control (18.06±2.1mV2/Hz) or one hour Al pre-incubated slices (11.3±2.5mV2/Hz). Intriguingly wash-out, after three to four hours of Al incubation, failed to restore baseline oscillation power and its facilitation by nicotine as no difference was observed in gamma oscillation peak power between Al wash-out slices (3.4±1.1mV2/Hz) and slices without washout (3.6±0.9mV2/Hz). Conclusion: This study shows that at cellular level, exposure of hippocampal tissue to Al compromised nAChR-mediated facilitation of cholinergic hippocampal gamma oscillations. Longer in vitro Al exposure caused permanent changes in hippocampal oscillogenic circuitry and changed its sensitivity to nAChR-modulation. This study will help to understand the possible mechanism of cognitive decline induced by Al.

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Anisomycin inhibits the late maintenance of long-term depression in rat hippocampal slices in vitro

Neuroscience Letters ◽

10.1016/s0304-3940(02)01400-3 ◽

2003 ◽

Vol 338 (2) ◽

pp. 147-150 ◽

Cited By ~ 43

Author(s):

Sreedharan Sajikumar ◽

Julietta U. Frey

Keyword(s):

Hippocampal Slices ◽

Long Term Depression

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Activation of metabotropic glutamate receptors induces long-term depression of GABAergic inhibition in hippocampus

Journal of Neurophysiology ◽

10.1152/jn.1993.69.3.1000 ◽

1993 ◽

Vol 69 (3) ◽

pp. 1000-1004 ◽

Cited By ~ 67

Author(s):

Y. B. Liu ◽

J. F. Disterhoft ◽

N. T. Slater

Keyword(s):

Glutamate Receptors ◽

Metabotropic Glutamate Receptors ◽

Hippocampal Slices ◽

Input Resistance ◽

Nmda Receptor Antagonist ◽

Metabotropic Glutamate ◽

Epileptiform Discharges ◽

Bath Application

1. The long-term enhancement of synaptic excitability in CA1 hippocampal pyramidal neurons produced by activation of metabotropic glutamate receptors (mGluRs) was studied in rabbit hippocampal slices in vitro. 2. Bath application of the mGluR agonist (1S,3R)-1-aminocyclopentane-1,3- dicarboxylic acid (1S,3R-ACPD) (5-20 microM) for 20 min produced a reversible depolarization of membrane potentiatil, blockade of spike accommodation, and increase in input resistance of CA1 neurons. However, a long-lasting increase in synaptic excitability was observed: single stimuli applied to the Schaffer collateral commisural fiber pathway evoked epileptiform discharges in the presence of 1S,3R-ACPD and after the washout of 1S,3R-ACPD, persistent paroxysmal depolarization shifts (PDSs) were evoked by afferent stimulation. A long-lasting enhancement of synaptic excitability was also observed in the presence of the NMDA receptor antagonist D-(-)-2-amino-5-phosphonopentanoic acid (D-AP5), which blocked the stimulation-evoked PDS and associated afterdischarges. 3. When biphasic, monosynaptically evoked inhibitory post-synaptic potentials (IPSPs) were recorded in the presence of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) (10–15 microM) and D-AP5 (20 microM), the bath application of 1S,3R-ACPD produced a significant reduction (approximately 50%) of both components of the IPSP, which persisted after the washout of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

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Neuroprotective properties of mitochondria-targeted antioxidants of the SkQ-type

Reviews in the Neurosciences ◽

10.1515/revneuro-2016-0036 ◽

2016 ◽

Vol 27 (8) ◽

pp. 849-855 ◽

Cited By ~ 17

Author(s):

Nickolay K. Isaev ◽

Elena V. Stelmashook ◽

Elisaveta E. Genrikhs ◽

Galina A. Korshunova ◽

Natalya V. Sumbatyan ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Brain Area ◽

Hippocampal Slices ◽

Amyloid Β ◽

Long Term Potentiation ◽

Term Potentiation ◽

Neuroprotective Action

AbstractIn 2008, using a model of compression brain ischemia, we presented the first evidence that mitochondria-targeted antioxidants of the SkQ family, i.e. SkQR1 [10-(6′-plastoquinonyl)decylrhodamine], have a neuroprotective action. It was shown that intraperitoneal injections of SkQR1 (0.5–1 μmol/kg) 1 day before ischemia significantly decreased the damaged brain area. Later, we studied in more detail the anti-ischemic action of this antioxidant in a model of experimental focal ischemia provoked by unilateral intravascular occlusion of the middle cerebral artery. The neuroprotective action of SkQ family compounds (SkQR1, SkQ1, SkQTR1, SkQT1) was manifested through the decrease in trauma-induced neurological deficit in animals and prevention of amyloid-β-induced impairment of long-term potentiation in rat hippocampal slices. At present, most neurophysiologists suppose that long-term potentiation underlies cellular mechanisms of memory and learning. They consider inhibition of this process by amyloid-β1-42as anin vitromodel of memory disturbance in Alzheimer’s disease. Further development of the above studies revealed that mitochondria-targeted antioxidants could retard accumulation of hyperphosphorylated τ-protein, as well as amyloid-β1-42, and its precursor APP in the brain, which are involved in developing neurodegenerative processes in Alzheimer’s disease.

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Size Does Matter: Generation of Intrinsic Network Rhythms in Thick Mouse Hippocampal Slices

Journal of Neurophysiology ◽

10.1152/jn.00806.2004 ◽

2005 ◽

Vol 93 (4) ◽

pp. 2302-2317 ◽

Cited By ~ 54

Author(s):

Chiping Wu ◽

Wah Ping Luk ◽

Jesse Gillis ◽

Frances Skinner ◽

Liang Zhang

Keyword(s):

In Vitro Model ◽

Adult Mouse ◽

Hippocampal Slices ◽

Network Connectivity ◽

Slice Preparation ◽

Fundamental Properties ◽

Mouse Hippocampus ◽

Hippocampal Network ◽

Vitro Model

Rodent hippocampal slices of ≤0.5 mm thickness have been widely used as a convenient in vitro model since the 1970s. However, spontaneous population rhythmic activities do not consistently occur in this preparation due to limited network connectivity. To overcome this limitation, we develop a novel slice preparation of 1 mm thickness from adult mouse hippocampus by separating dentate gyrus from CA3/CA1 areas but preserving dentate–CA3-CA1 connectivity. While superfused in vitro at 32 or 37°C, the thick slice exhibits robust spontaneous network rhythms of 1–4 Hz that originate from the CA3 area. Via assessing tissue O2, K+, pH, synaptic, and single-cell activities of superfused thick slices, we verify that these spontaneous rhythms are not a consequence of hypoxia and nonspecific experimental artifacts. We suggest that the thick slice contains a unitary circuitry sufficient to generate intrinsic hippocampal network rhythms and this preparation is suitable for exploring the fundamental properties and plasticity of a functionally defined hippocampal “lamella” in vitro.

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