Ariel L. Escobar (1962–2024), dear colleague, mentor, and friend, left us this past December 20, 2024, at the early age of 62. Ariel was an avid scientist with a special talent for solving intricate technical problems when understanding calcium dynamics in muscle. Originally from Argentina, Ariel was born in the southern coastal town of Comodoro-Rivadavia on March 25, 1962. Ariel was the only child of José Escobar and Nélida Roggero. After serving in the army around the time of the Falklands (Malvinas) war, Ariel went to study electronic engineering at Universidad Tecnológica Nacional in Buenos Aires. He then worked with Osvaldo Uchitel on potassium currents in skeletal muscle and started the journey that made him the beloved scientist that many of us had the privilege to know and call a friend.
Ariel crossed the estuary of Rio de la Plata to begin his doctoral studies under the direction of Gustavo Brum and Gonzalo Pizarro, at the School of Medicine of Universidad de la Republica in Montevideo, Uruguay, where he began developing a passion for biophysical problems, including the excitation-contraction problem in muscles, which constituted a hot topic in the field at that time. As a student, Ariel went to work as a research associate in the United States with Enrico Stefani (Baylor, 1991) and Julio Vergara (University of California, Los Angeles [UCLA], 1991–1993). This work earned him a PhD in 1993 with Vergara as advisor.
Ariel moved to UCLA as a postdoc, where he developed in confocal spot technique in the laboratory of Vergara. Using this technique, Ariel was able to pinpoint the functional site of Ca2+ releasing in an intact fiber with diffraction limited resolution. This work was published in Nature in 1994, constituting his first major publication in his career and the central piece of his PhD, awarded by the Program for the Development of the Basic Sciences, in Uruguay.
After his time at UCLA, in 1995 Ariel moved to Venezuela, the birthplace of his beloved wife Tania. Ariel joined the faculty of the Instituto Venezolano de Investigaciones Científicas (IVIC), where he collaborated with highly regarded scientists such as Carlo Caputo and Reinaldo DiPolo. At IVIC, Ariel further developed the idea of local Ca2+ measurements in muscle, focusing now on the heart. His achievements in IVIC include the combination of experimental and computational tools to understand the implication of the subcellular arrangement of the Ca2+ release machinery in the kinetics of Ca2+ signaling. Furthermore, he also developed the pulsed local-field fluorescence microscopy (PLFFM) technique that became one of the workhorses of his lab for the rest of his career.
In 2000, Ariel moved his laboratory to Texas Tech University Health Sciences Center, Lubbock, where he further developed the PLFFM technique to study Ca2+ dynamics in the intact heart, exploring the role of intracellular Ca2+ storage, the role of Ca2+ extrusion systems, and under pathological conditions such as ischemia and ischemia-reperfusion.
In the last leg of his journey, Ariel joined the school of Engineering at the University of California, Merced in 2009, where he continued his work on Ca2+ signaling, then exploring the relationship between electrical excitation and Ca2+ release. During that time, Ariel focused on, among other questions, the complicated problem of alternant T-waves, an arrhythmogenic phenomenon. Utilizing a challenging experimental system that included loose patch clamp of intact hearts in combination with flash photolysis at the pipette tip, Ariel and colleagues provided some of the first concrete evidence linking currents mediated by the sodium-calcium exchanger and alternant T-waves.
Ariel was an outstanding scientist, with privileged—even enviable—prowess for mechanistic understanding of physiological processes and incredible ability for technical development. Yet, beyond that, Ariel was a very caring and generous person who loved cultivating his friendships. He thoroughly enjoyed entertaining his friends by cooking them meals from around the world. It is common to see that anyone who shared more than one day with Ariel has great memories to share.
Ariel was a passionate scientist who saw research not as a job but as a way of life. He loved his country of Argentina and dreamed of advancing science throughout parts of Latin America where resources continue to be limited. He also helped younger researchers establish their own laboratories and collaborated with many scientist friends from around the world. Ariel leaves behind his wife Tania and so many friends that consider themselves part of his family. We, those who had the fortune of interacting with Ariel and called him a friend, already miss him terribly. Chao, Ariel.
—Carlos Villalba-Galea