Ant Brain Research Articles

Cerebral larvae in the second intermediate host ofDicrocoelium dendriticum (Rudolphi, 1819) andDicrocoelium hospes looss, 1907 (Trematodes, Dicrocoeliidae)

Cerebral larvae of Dicorcoelium dendriticum and D. hospes and the brains of infected ants were studied. Morphologic differences of the freed larvae could not be found, but there were evident differences in number and localization of the cerebral stages. Ants infected with D. dendriticum usually showed one "Hirnwurm" while in the majority of the ants infected with D. hospes two larvae were found. The typical localization of the "Hirnwurm" of D. dendriticum was in the ventral part of the subesophageal ganglion; almost every larva of D. hospes was found in the dorsal part of an antennal lobe. The cyst walls of the larvae were visible only in some specimens. Their thickness seemed to depend on the localization of the larva. Differences in number and localization of the larvae, and hypotheticalmechanisms how they could influence the behavior of their hosts are discussed.

Comparative Microelectrophoretic Studies of Invertebrate and Vertebrate Neurones

The comparative study between the central neurons of arthropods (ants) and of vertebrates (rats and cats) shows similarities and dissimilarities. Acetylcholine (ACh) activates and, in a few instances, inhibits central neurons in the ant and in vertebrates similarly, but ACh-sensitive neurons are less frequently encountered in insects. γ -Aminobutyric acid inhibits neuronal activity in the central nervous tissue in the ant and in vertebrates similarly. In contrast, l -glutamic acid, which activates neurons in vertebrates, may not only exhibit the same effect to a less extent in the ant brain but also inhibit central neurons in vertebrates. Dopamine inhibits some neurons of both arthropods and vertebrates. The strong inhibitory effect of dopamine in parts of the central nervous tissue of the ant correlates well with the presence of catecholamine-containing nerve cells in the brain of the cockroach.