The heat-production and recovery of crustacean nerve

Abstract

The heat-production of crab''s nerve has been measured in a short tetanus. These nerves are very fatigable. The total heat per sec. of maximal stimulation is at least 2.5 X10-3 calorie per gm. of moist nerve. This is about 33 times as great as for frog''s nerve. An analysis of the heat-production shows a clear division into two phases, initial and recovery. The initial process, completed during stimulation, yields only about 2 1/4% of the total heat. The recovery process, lasting for about 25 min. at 16[degree], supplies the remainder. The maximum rate of recovery heat production occurs almost immediately after the stimulus and at 15[degree] C. is about 65% of the initial heat per sec This agrees closely with Gerard''s determination in frog''s nerve. The results are discussed in relation to Levin''s "retention of action current" and to Furu-sawa''s hypothesis that in the presence of O a crab''s nerve "depolarised"'''' by activity is recharged by an active combustion process. The behavior of the crab''s nerve during life is discussed, and it is pointed out that in certain respects a crab''s nerve probably presents a closer analogy to certain phenomena occurring in the central nervous system than does the medullated nerve of the frog.