Epileptiform activity in mouse hippocampal slices induced by moderate changes in extracellular Mg ²⁺ , Ca ²⁺ , and K ^.

Publisher: BioMed Central Country of Publication: England NLM ID: 100966986 Publication Model: Electronic Cited Medium: Internet ISSN: 1471-2202 (Electronic) Linking ISSN: 14712202 NLM ISO Abbreviation: BMC Neurosci Subsets: MEDLINE

Original Publication: London: BioMed Central, [2000-

Calcium/*metabolism ; Extracellular Fluid/*metabolism ; Hippocampus/*metabolism ; Magnesium/*metabolism ; Potassium/*metabolism ; Seizures/*metabolism; Age Factors ; Animals ; Calcium/toxicity ; Extracellular Fluid/drug effects ; Hippocampus/drug effects ; Hippocampus/physiopathology ; Magnesium/toxicity ; Male ; Mice ; Mice, Inbred C57BL ; Organ Culture Techniques ; Potassium/toxicity ; Seizures/chemically induced ; Seizures/physiopathology

Background: Rodent brain slices-particularly hippocampal slices-are widely used in experimental investigations of epileptiform activity. Oxygenated artificial cerebrospinal fluid (ACSF) is used to maintain slices in vitro. Physiological or standard ACSF containing 3-3.5 mM K ⁺ , 1-2 mM Mg ²⁺ , and 1-3 mM Ca ²⁺ generally does not induce population epileptiform activity, which can be induced by ACSF with high K ⁺ (8-10 mM), low Mg ²⁺ , or low Ca ²⁺ alone or in combination. While low-Mg ²⁺ ACSF without intentionally added Mg salt but with contaminating Mg ²⁺ (≤ 50-80 µM) from other salts can induce robust epileptiform activity in slices, it is unclear whether such epileptiform activity can be achieved using ACSF with moderately decreased Mg ²⁺ . To explore this issue, we examined the effects of moderately modified (m)ACSF with 0.8 mM Mg ²⁺ , 1.3 mM Ca ²⁺ , and 5.7 mM K ⁺ on induction of epileptiform discharges in mouse hippocampal slices.
Results: Hippocampal slices were prepared from young (21-28 days old), middle-aged (13-14 months old), and aged (24-26 months old) C57/BL6 mice. Conventional thin (0.4 mm) and thick (0.6 mm) slices were obtained using a vibratome and pretreated with mACSF at 35-36 °C for 1 h prior to recordings. During perfusion with mACSF at 35-36 °C, spontaneous or self-sustained epileptiform field potentials following high-frequency stimulation were frequently recorded in slices pretreated with mACSF but not in those without the pretreatment. Seizure-like ictal discharges were more common in thick slices than in thin slices.
Conclusions: Prolonged exposure to mACSF by pretreatment and subsequent perfusion can induce epileptiform field potentials in mouse hippocampal slices.
(© 2021. The Author(s).)

J Neurophysiol. 2005 Apr;93(4):2302-17. (PMID: 15537814)
Exp Brain Res. 1991;87(3):581-96. (PMID: 1783028)
Front Cell Neurosci. 2014 Jan 08;7:262. (PMID: 24409118)
Epilepsia. 2010 Mar;51(3):423-31. (PMID: 19694791)
Nature. 1984 May 17-23;309(5965):261-3. (PMID: 6325946)
Biol Trace Elem Res. 2009 Jul;130(1):7-12. (PMID: 19165425)
Front Pharmacol. 2018 May 18;9:451. (PMID: 29867462)
Neurobiol Dis. 2012 Dec;48(3):495-506. (PMID: 22782081)
BMC Neurosci. 2021 May 17;22(1):37. (PMID: 34001031)
J Neurosci Methods. 2016 Oct 15;272:50-55. (PMID: 27044802)
Prog Brain Res. 2007;163:627-37. (PMID: 17765742)
J Neurophysiol. 2012 Jan;107(1):417-23. (PMID: 22031777)
J Neurophysiol. 2005 Jul;94(1):741-53. (PMID: 15772241)
Exp Brain Res. 1993;96(2):230-40. (PMID: 7903641)
J Neurosci Methods. 2016 Feb 15;260:26-32. (PMID: 26484784)
Nature. 1984 Feb 2-8;307(5950):462-5. (PMID: 6320006)
Cell Syst. 2017 Dec 27;5(6):591-603.e4. (PMID: 29248375)
J Neurosci Methods. 2009 Oct 15;183(2):107-13. (PMID: 19524611)
Exp Neurol. 2015 Sep;271:1-12. (PMID: 25943585)
J Neurosurg. 1990 Dec;73(6):889-900. (PMID: 1977896)
Epilepsia. 2017 Nov;58 Suppl 4:40-52. (PMID: 29105075)
Epilepsy Res. 2015 Feb;110:166-70. (PMID: 25616469)
Lancet Neurol. 2016 Feb;15(2):185-197. (PMID: 26597090)
Front Neural Circuits. 2015 May 29;9:27. (PMID: 26074779)
Front Cell Neurosci. 2018 Aug 29;12:278. (PMID: 30210302)
Neuroscience. 2002;109(3):517-30. (PMID: 11823063)
J Neurophysiol. 1987 Mar;57(3):869-88. (PMID: 3031235)
J Neurosci Res. 2017 Nov;95(11):2217-2235. (PMID: 28463438)
Hippocampus. 2009 Feb;19(2):205-20. (PMID: 18785213)
Epilepsia. 2009 Jan;50(1):99-115. (PMID: 18727680)
Epilepsia Open. 2018 Nov 02;3(4):460-473. (PMID: 30525115)
Brain Res Dev Brain Res. 1995 Jul 14;87(2):145-52. (PMID: 7586496)
Hippocampus. 2004;14(8):935-47. (PMID: 15390177)
Genes Brain Behav. 2009 Jul;8(5):481-92. (PMID: 19493016)
J Neurosci. 2011 Apr 20;31(16):6221-34. (PMID: 21508245)
J Neurochem. 1996 Jun;66(6):2477-83. (PMID: 8632172)
Neurobiol Dis. 2006 Aug;23(2):312-28. (PMID: 16815026)
Brain Res. 1986 Nov 19;398(1):215-9. (PMID: 3801897)
Prog Neurobiol. 2020 Oct;193:101802. (PMID: 32413398)
Neuroscience. 2014 Sep 26;277:474-85. (PMID: 25088916)
J Physiol. 2008 Jan 15;586(2):477-94. (PMID: 17991696)
Handb Clin Neurol. 2009;93:613-21. (PMID: 18804671)
Brain Res. 1990 Mar 19;511(2):280-90. (PMID: 1970748)
J Neurosci. 2012 Feb 15;32(7):2499-512. (PMID: 22396423)

Keywords: Artificial cerebrospinal fluid; Epilepsy; Extracellular ion; Ictal-like discharge; Interictal-like spike; Seizure

I38ZP9992A (Magnesium)
RWP5GA015D (Potassium)
SY7Q814VUP (Calcium)

Date Created: 20210724 Date Completed: 20220201 Latest Revision: 20220201

20250114

PMC8305515

10.1186/s12868-021-00650-3

34301200