Leucine incorporation in the ganglia of praying mantids during a learning process

Abstract

Leucine incorporation into four ganglia (‘brain’. B; prothoracic ganglion, P; mesothoracic ganglion, M; and metathoracic ganglion, T) was studied in mantids ( Stagmatoptera biocellata) trained not to attack a black star figure in movement. There were two experimental groups, i.e. LM and WH experimental groups, and one control group. The LM and WH groups differed in the experimental conditions of training in such a way that both had similar motor activity and sensorial stimulation but only one of them evinced learning ( Maldonado and Tablante, 1975). After training, incorporation of | 14C| leucine into P and B was greater in experimental than in control animals. This result is not necessarily related to learning because no difference was found between LM and WH experimental groups. The metabolic gradient of the four ganglia of the experimental animals was P→B→M→T, whereas that found for the control group was M→T→P→B. The authors interpret these findings as supporting a hypothesis previously set forth that correlates the metabolic gradient in the four ganglia with differences regarding control of motor activity and/or sensorial input. Experiments involving double labelling and electrophoresis indicated that the P and B changes after training involved all the proteins, and were not restricted to one or a few protein species.