Just after obtained his Ph.D. degree working on the structure of the sensory and vegetative ganglia (see next epigraph), and together with the skills acquired in this time on histological techniques, Fernando de Castro started to work on the innervation of the aorto-carotid region. During the first two decades of the XXth century, this region was target of multiple studies following the description of the respiratory reflexes by Heinrich Hering. Two capital studies by De Castro founded the anatomical basis for these reflexes (published in 1926 and 1928). In them, Fernando de Castro described the separated distribution of baroreceptors in the carotid sinus, as well as chemoreceptors in the carotid body (or glomus caroticum), a small structure closet o the carotid bifurcation. He also demonstrated the sensory nature of this innervation, separated from nerve fibres coming from the vegetative ganglia. The most potent physiopharmacological group at that time, that of Corneille Heymans (1892-1968) at Ghent University (Belgium) envisioned the relevance of De Castro´s work and, after inviting Fernando de Castro to Ghent to perform different experiments together, the so called Ghent School decided to focus on the carotid body (moving away from the carotid sinus) for their studies on the arterial chemoreceptors. This decisión was crucial for Corneille Heymans work, and he was awarded with the 1938 Nobel Prize in Physiology or Medicine while Fernando de Castro was under severe life danger in Madrid, defending the Cajal Institute from looting during the Spanish Civil War (1936-1939). The Swedish Nobel Academy forgot De Castro´s description, although it has been repeatedly and world-wide recognised the fundamental contribution of the young Spaniard neuroscientist and his merits to share the Nobel Prize with Corneille Heymans.

Fernando de Castro pursued this research line with important contributions published in 1940, 1944, 1950, 1951, 1962 and the postumous at 1968.


In this section, we show original drawings from Fernando de Castro on:

            -figure I.1 the carotid body (originally published in: de Castro, 1926)

            -figure I.2 the innervation of the carotid region (originally published in: de Castro, 1926)

           -figure I.3 a baroreceptor from the carotid sinus (originally published in: de Castro, 1928)

-figure I.4 a sympathetic microganglion within one of the nerve branches innervating the carotid body (originally published in: de Castro, 1926).

-figure I.5 innervation of the carotid sinus by baroreceptors to detect changes in blood presure (originally published in: de Castro, 1928)

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