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Pregnenolone sulfate enhances spontaneous glutamate release by inducing presynaptic Ca2+-induced Ca2+ release.
Neuroscience 2010; 171(1):106-16N

Abstract

Pregnenolone sulfate (PS) acts as an excitatory neuromodulator and has a variety of neuropharmacological actions, such as memory enhancement and convulsant effects. In the present study, we investigated the effect of PS on glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) in acutely isolated dentate gyrus (DG) hilar neurons by use of a conventional whole-cell patch-clamp technique. PS significantly increased sEPSC frequency in a concentration-dependent manner without affecting the current amplitude, suggesting that PS acts presynaptically to increase the probability of spontaneous glutamate release. However, known molecular targets of PS, such as α7 nicotinic ACh, NMDA, σ1 receptors and voltage-dependent Ca(2+) channels, were not responsible for the PS-induced increase in sEPSC frequency. In contrast, the PS-induced increase in sEPSC frequency was completely occluded in a Ca(2+)-free external solution, and was significantly reduced by either the depletion of presynaptic Ca(2+) stores or the blockade of ryanodine receptors, suggesting that PS elicits Ca(2+)-induced Ca(2+) release (CICR) within glutamatergic nerve terminals. In addition, the PS-induced increase in sEPSC frequency was completely occluded by transient receptor potential (TRP) channel blockers. These data suggest that PS increases spontaneous glutamate release onto acutely isolated hilar neurons via presynaptic CICR, which was triggered by the influx of Ca(2+) through presynaptic TRP channels. The PS-induced modulation of excitatory transmission onto hilar neurons could have a broad impact on the excitability of hilar neurons and affect the pathophysiological functions mediated by the hippocampus.

Authors+Show Affiliations

Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 700-412, Republic of Korea.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

20816925

Citation

Lee, K H., et al. "Pregnenolone Sulfate Enhances Spontaneous Glutamate Release By Inducing Presynaptic Ca2+-induced Ca2+ Release." Neuroscience, vol. 171, no. 1, 2010, pp. 106-16.
Lee KH, Cho JH, Choi IS, et al. Pregnenolone sulfate enhances spontaneous glutamate release by inducing presynaptic Ca2+-induced Ca2+ release. Neuroscience. 2010;171(1):106-16.
Lee, K. H., Cho, J. H., Choi, I. S., Park, H. M., Lee, M. G., Choi, B. J., & Jang, I. S. (2010). Pregnenolone sulfate enhances spontaneous glutamate release by inducing presynaptic Ca2+-induced Ca2+ release. Neuroscience, 171(1), pp. 106-16. doi:10.1016/j.neuroscience.2010.07.057.
Lee KH, et al. Pregnenolone Sulfate Enhances Spontaneous Glutamate Release By Inducing Presynaptic Ca2+-induced Ca2+ Release. Neuroscience. 2010 Nov 24;171(1):106-16. PubMed PMID: 20816925.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Pregnenolone sulfate enhances spontaneous glutamate release by inducing presynaptic Ca2+-induced Ca2+ release. AU - Lee,K H, AU - Cho,J H, AU - Choi,I S, AU - Park,H M, AU - Lee,M G, AU - Choi,B J, AU - Jang,I S, Y1 - 2010/09/17/ PY - 2010/05/01/received PY - 2010/07/27/revised PY - 2010/07/27/accepted PY - 2010/9/7/entrez PY - 2010/9/8/pubmed PY - 2011/2/3/medline SP - 106 EP - 16 JF - Neuroscience JO - Neuroscience VL - 171 IS - 1 N2 - Pregnenolone sulfate (PS) acts as an excitatory neuromodulator and has a variety of neuropharmacological actions, such as memory enhancement and convulsant effects. In the present study, we investigated the effect of PS on glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) in acutely isolated dentate gyrus (DG) hilar neurons by use of a conventional whole-cell patch-clamp technique. PS significantly increased sEPSC frequency in a concentration-dependent manner without affecting the current amplitude, suggesting that PS acts presynaptically to increase the probability of spontaneous glutamate release. However, known molecular targets of PS, such as α7 nicotinic ACh, NMDA, σ1 receptors and voltage-dependent Ca(2+) channels, were not responsible for the PS-induced increase in sEPSC frequency. In contrast, the PS-induced increase in sEPSC frequency was completely occluded in a Ca(2+)-free external solution, and was significantly reduced by either the depletion of presynaptic Ca(2+) stores or the blockade of ryanodine receptors, suggesting that PS elicits Ca(2+)-induced Ca(2+) release (CICR) within glutamatergic nerve terminals. In addition, the PS-induced increase in sEPSC frequency was completely occluded by transient receptor potential (TRP) channel blockers. These data suggest that PS increases spontaneous glutamate release onto acutely isolated hilar neurons via presynaptic CICR, which was triggered by the influx of Ca(2+) through presynaptic TRP channels. The PS-induced modulation of excitatory transmission onto hilar neurons could have a broad impact on the excitability of hilar neurons and affect the pathophysiological functions mediated by the hippocampus. SN - 1873-7544 UR - https://www.unboundmedicine.com/medline/citation/20816925/Pregnenolone_sulfate_enhances_spontaneous_glutamate_release_by_inducing_presynaptic_Ca2+_induced_Ca2+_release_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0306-4522(10)01060-2 DB - PRIME DP - Unbound Medicine ER -