Juan Ferreira

Graduate Student

Holy Lab | Santi Lab | Google Scholar

Research interests

I am an electrophysiologist and yes, I really enjoy looking at figures with currents. I started working on measuring voltage-sensing modules (VSMs) of CaV1.1 calcium channels and the associated gating of RyR1 channels in the sarcoplasmic reticulum, in skeletal muscle (Excitation Contraction Coupling). After a few years, I explored other Ion channels, including potassium, sodium, and chloride channels, in different systems and tissues, from cardiac, skeletal, and smooth muscle cells to neurons and spermatozoa. Today I have focused on the study of potassium and calcium channels which are key regulators of excitable cells activity.

In general, I am interested in understanding how the modulation of ion channels by different factors can affect organ physiology and human or animal behavior. Particularly, I am exploring how the regulation of potassium and sodium channels can modulate uterine excitability (frequency and intensity of uterus contractions during pregnancy). I am also interested in exploring the involvement of potassium channels in the regulation of milk excretion and parenthood behavior/bonding after pregnancy.  


BS, Human Biology, School of Sciences, Universidad de la República (UdelaR), Montevideo, Uruguay.  Thesis: “Effects of inorganic phosphate on calcium release in skeletal muscle.”

Honors and awards

2011-2013, Junior Investigator Grant: “Charge movement in mammalian skeletal muscle and its dependence with the voltage and extracellular cations” 

  • $20,000-$30,000 for two years 
  • Advisor: Gustavo Brum
  • Funded by: Comisión Sectorial de Investigación Científica, CSIC. Initiation Grants. Department of Biophysics, School of Medicine. Montevideo-Uruguay. 
  • Peer-reviewed publication published with these funds: 
    Ferreira Gregorio J, Pequera G, Manno C, Ríos E, Brum G. “The voltage sensor of excitation-contraction coupling in mammals: Inactivation and interaction with Ca2“. Journal of General Physiology. Nov 6, 2017; 149(11):1041-1058. doi: 10.1085/jgp.201611725. Epub Oct 11, 2017.

2008-2009, Advanced Student Grant: “Electrophysiological properties of skeletal muscle of mice and rat carrying the asymptomatic SOD1 mutation (A93D)” 

  • Advisor: Gustavo Brum
  • Funded by: Comisión Sectorial de Investigación Científica, CSIC. Grants for Advanced Students. Department of Biophysics, School of Medicine. Montevideo-Uruguay


  • Ferreira JJ, Cassina A, Irigoyen P, Ford M, Pietroroia S, Peramsetty N, Radi R, Santi CM, Sapiro R. Increased mitochondrial activity upon CatSper channel activation is required for sperm capacitation. Redox Biology. Online November 1, 2021; 102176. doi: 10.1016/j.redox.2021.102176.  
  • Ferreira JJ1, Amazu C1, Puga-Molina LC, Ma X, England SK,* Santi CM*. SLO2.1/NALCN a sodium signaling complex that regulates uterine activity. iScience. 2021; 24(11):103210. doi: 10.1016/j.isci.2021.103210. 
    *Co-corresponding authors, and 1 Equal contribution.
  • Ferreira JJ, Lybaert P, Puga-Molina LC, Santi CM. Conserved mechanism of bicarbonate-induced sensitization of CatSper channels in human and mouse sperm. Frontiers in Cell and Developmental Biology-Cell Growth and Division. September 28, 2021; 9:733653. doi: 10.3389/fcell.2021.733653.
  • Ferreira JJ, Pequera G, Launikonis BS, Ríos E, Brum G. A chloride channel blocker prevents the suppression by inorganic phosphate of the cytosolic calcium signals that control muscle contraction. J Physiol. Jan 2021; 599(1):157-170. doi: 10.1113/JP279917. Epub Oct 19, 2020.
  • Amazu C, Ma X, Henkes C, Ferreira JJ, Santi CM, England SK. Progesterone and estrogen regulate NALCN expression in human myometrial smooth muscle cells. Am J Physiol Endocrinol Metab. Apr 1, 2020; 318(4):E441-E452. doi: 10.1152/ajpendo.00320.2019. Epub Jan 14, 2020. 
  • Amazua C,1 Ferreira JJ,1 Santi CM, England SK. Sodium channels and transporters in the myometrium. Current Opinion in Physiology. 2020; Volume 13.
    1Both authors contributed equally to this work. 
  • Li P, Halabi CM, Stewart R, Butler A, Brown B, Xia X, Santi C, England S, Ferreira J, Mecham RP, Salkoff L. Sodium-activated potassium channels moderate excitability in vascular smooth muscle. J Physiol. Oct, 2019; 597(20):5093-5108. doi: 10.1113/JP278279. Epub Oct 1, 2019.
  • Ferreira JJ, Butler A, Stewart R, Gonzalez-Cota AL, Lybaert P, Amazu C, Reinl EL, Wakle-Prabagaran M, Salkoff L, England SK, Santi CM. Oxytocin can regulate myometrial smooth muscle excitability by inhibiting the Na+-activated K+ channel, Slo2.1. J Physiol. Jan 2019; 597(1):137-149. doi: 10.1113/JP276806. Epub 2018 Nov 22.
  • Ferreira Gregorio J, Pequera G, Manno C, Ríos E, Brum G. The voltage sensor of excitation-contraction coupling in mammals: Inactivation and interaction with Ca2+. Journal of General Physiology. Nov 6, 2017; 149(11):1041-1058. doi: 10.1085/jgp.201611725. Epub Oct 11, 2017.
  • Ferreira JJ*, Geng Y*, Dzikunu V, Butler A, Lybaert P, Yuan P, Magleby KL, Salkoff L, Santi CM. A genetic variant of the sperm-specific SLO3 K+ channel has altered pH and Ca2+ sensitivities. The Journal of Biological Chemistry. May 26, 2017; 292(21):8978-8987. doi: 10.1074/jbc.M117.776013. Epub Apr 4, 2017. 
    *Both authors contributed equally to this work. 
  • Budelli G, Sun Q, Ferreira J, Butler A, Santi CM, Salkoff L. SLO2 Channels are inhibited by divalent cations that activate SLO1 K+ channels. The Journal of Biological Chemistry. Apr 1, 2016; 291(14):7347-56. doi: 10.1074/jbc.M115.709436. Epub Jan 28, 2016.
  • Cintia Stival C, Florenza A. La Spina FA, Baró Graf C, Arcelay E, Arranz SE, Ferreira JJ, Le Grand S, Dzikunu VA, Santi CM, Visconti PE, Buffone MG, Krapf D. Src is the connecting player between PKA activation and hyperpolarization through SLO3, regulation in mouse sperm. The Journal of Biological Chemistry. Jul 24, 2015; 290(30):18855-64. doi: 10.1074/jbc.M115.640326. Epub Jun 9, 2015.
  • Chávez JC, Ferreira JJ, Butler A, De La Vega Beltrán JL, Treviño CL, Darszon A, Salkoff L, Santi CM. The Journal of Biological Chemistry. November 14, 2014; 289(46):32266-32275. doi: 10.1074/jbc.M114.607556. Epub Sep 30, 2014.