Fainting goat
It is characterised by myotonia congenita, a hereditary condition that may cause it to stiffen or fall over when excited or startled.
[7] The myotonic goat is important in history for researching and clarifying the role of chloride in muscle excitation.
[11] The experiments of Brown and Harvey in 1939 with the myotonic goat made a major contribution to the understanding of the physiological basis of this condition and influenced many other theories of myotonia and its causes.
[5] In 2019, the myotonic goat's conservation status was listed as "at risk" in the DAD-IS database of the Food and Agriculture Organization of the United Nations.
[15][16] In affected goats, the CLCN1 gene contains a missense mutation; the amino acid alanine is replaced with a proline residue.
[14] After stimulation, in myotonia congenita there is an increased tendency of the muscle fibers to respond with repetitive action potentials and after discharges.
[18] The muscle fibers of the myotonic goat were found to be highly (electrically) resistive, corresponding to the blocking of chloride conductance.
[5] In a study, normal goat muscle fibers could be made myotonic by blocking the chloride conductance using myotonia inducing drugs, or by substituting in an anion that is unable to pass through a semi-permeable membrane.
[19] These differences help to explain increases in the severity of myotonia in the whole animal that occurs upon decreasing the temperature of the involved muscles.
[20] Previous studies have also reported that taurine, an amino sulphonic acid, when given to myotonic patients can reduce the symptoms of the condition.
[23] From the study above, it was found that a change in the nucleotide sequence caused a proline substitution for alanine residue in the carboxyl terminus of the goat's chloride channel.
[6] White and Plaskett reported seeing these goats in five counties in Tennessee: Marshall, Giles, Lawrence, Maury, and Coffee.
[6] Dr. White (in a letter to the author) stated that in the summer of 1929 in Egypt, he witnessed several fainting goats between the Suez Canal and the Palestine border.
[6] He also stated that he shipped some of the goats from Tennessee to a professor by the name of Nagel, at the Nervous Disease Institute in Germany for studies.
[24] The tendency of goats to spasm has been attested as early as the Hippocratic Corpus, where analogies are drawn from the phenomenon to human illness.
[25] The experiments of Brown and Harvey in 1939 with the myotonic goat made a major contribution to the understanding of the physiological basis of this condition and influenced many other theories of myotonia and its causes.
[5] Meat production from goats uses maternal breeds that demonstrate high levels of fitness under non-optimal situations.
