Ivan Tarkhanov (physiologist)
However, Tarkhnishvili's most significant contribution was the discovery of the influence of X-rays on the central nervous system, animal behavior, the heart and circulation, and embryonic development (1896-1903).
His father, Ramaz (Roman) Tarkhnishvili (Tarkhan-Mouravi) (1799-1871) achieved the distinguished rank of lieutenant-general for bravery in Russian-Turkey wars.
Tarknishvili was a descendant of an outstanding figure in the history of Georgia, the ruler Giorgi Saakadze (Didi Mouravi) (1570-1629), great commander of the Georgian army and a national hero in the seventeen century.
The eleven-year-old Vano, the precocious child of a Russian general active during the Caucasian Wars, interpreted for Alexandre Dumas while French writer was traveled to the Caucasus in 1858.
Dumas was equally affected the external beauty of the boy in the Georgian national raiment with dagger and excellent French speech that did not yield to the Parisians.
In 1860 father brought Ivan to St. Petersburg and enrolled him in Shakseeva's private boarding school where he remained for one year, before moving to the family of close relatives.
He realized his father's wishes and entered the Division of Natural Sciences of the Department of Physics and Mathematics at St. Petersburg University.
Here he gave five public lectures, which he went on to publish in Russian as “The Role of the Nervous System in Animal Movement” in the special supplement of the Proceedings of the Caucasian Medical Society (1872).
Returning to Russia, Tarkhanov submitted 15 works completed during his trip to the administration of St. Petersburg Medico-Surgical Academy for the title of Private Docent (1875).
From tracing Tarkhanov's life, it appears that his forced resignation from the Military Medical Academy and the lack of a formal position in which to conduct his scientific work were the main reasons for his untimely death at the age of 62.
In 1885 experiments on cutting and artificial emptying of the seminal vesicles, Tarkhanov showed that the latter played the crucial role in the generation of sexual excitement in frogs.
Proceeding from these experimental results, Tarkhanov put forward a hypothesis that filling and evacuation of the seminal vesicles were the main biological cause which led to sexual arousal and its disappearance in mammals and humans.
The skin galvanic reflex is still used in applied psychophysiology as part of the polygraph in lie detection in which changes are recorded in several physiological variables while the subject is asked a series of questions pertaining to a specific issue under investigation.
[5] After irradiating frogs and insects with X-rays in early 1896, several weeks after Röntgen's discovery, Tarkhanov concluded that these newly discovered rays not only photograph, but also "affect the living function".
These experiments confirmed that the impairment of reflexes after X-ray exposure depended on neither analgesia nor sensitive skin but on the moderating effect of the central nervous system (CNS) itself.
Tarkhanov (Tarkhnishvili) was one of those bridges, through which the people of Georgia joined with the best Russian and European science and culture, in searching for more advanced education, social progress, and independence.
