Automated analysis of behavior: a computer-controlled system for drug screening and the investigation of learning.

Efforts to understand cognition will be greatly facilitated by computerized systems that enable the automated analysis of animal behavior. A number of controversies in the invertebrate learning field have resulted from difficulties inherent in manual experiments. Driven by the necessity to overcome these problems during investigation of neural function in planarian flatworms and frog larvae, we designed and developed a prototype for an inexpensive, flexible system that enables automated control and analysis of behavior and learning. Applicable to a variety of small animals such as flatworms and zebrafish, this system allows automated analysis of innate behavior, as well as of learning and memory in a plethora of conditioning paradigms. We present here the schematics of a basic prototype, which overcomes experimenter effects and operator tedium, enabling a large number of animals to be analyzed with transparent on-line access to primary data. A scaled-up version of this technology represents an efficient methodology to screen pharmacological and genetic libraries for novel neuroactive reagents of basic and biomedical relevance.

Eye regeneration assay reveals an invariant functional left-right asymmetry in the early bilaterian, Dugesia japonica.

Consistent visceral asymmetry in vertebrates raises fascinating questions about the developmental mechanisms and evolutionary origin of fixed chirality of the left-right axis. One persistent controversy is whether consistently biased asymmetry is a later innovation imposed on a bilaterally symmetrical primitive body-plan, or whether asymmetry is a fundamental property predating the bilateria. The morphology of planaria suggests proximity to the origin of the bilateral body-plan, and they are commonly thought to be left-right symmetrical, as no consistent anatomical asymmetries have been described despite over a century of study of regeneration. Here, we show that D. japonica possess a consistent functional asymmetry in eye patterning defects caused by inhibition of H+/K+-ATPase activity (an ion flux mechanism recently shown to be an important early step in the asymmetry of several vertebrate embryos). Moreover, an endogenous transcript of the non-gastric H+/K+-ATPase subunit alpha is expressed in the head blastema shortly after amputation. Taken together, these data suggest that (1) left-right asymmetry is at least as old as planaria, (2) subtle functional asymmetries should be sought in other more primitive model systems that are believed to be symmetrical, and (3) symmetrical paired structures may in fact contain information about their position on the L or R side.