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Born in 1873, Otto Loewi was a German-American physiologist who made significant contributions to our understanding of the chemical transmission of nerve impulses. Loewi's groundbreaking experiment, known as the "frog heart experiment," demonstrated the release of a chemical substance, later identified as acetylcholine, at the nerve endings. This discovery paved the way for the field of neuropharmacology and the understanding of how neurotransmitters mediate communication between nerve cells.