RESUMEN
Analysis of the neural mechanisms of place navigation requires isolation of the landmark dependent allocentric and self-motion related idiothetic orientation modes. To assess their importance, rats were trained on a rotating (360 degrees/min) arena to avoid foot shocks applied in either a room frame defined sector of the arena or an idiothetically defined region of the floor. Independence of the respective allocentric and idiothetic engrams was revealed by simultaneous avoidance of both locations. The possibility that idiothetic orientation was confounded by allocentric intramaze cues was examined in an apparatus consisting of an inner rotating disc surrounded by a stationary belt. As long as the rat was on the moving disc, position of the 60 degrees shock sector was stable on the disk but projected from it to different parts of the belt. When the rat moved to the belt the shock sector was now stable on the belt, but its projection to the disk travelled over its moving surface. The rat always found the shock sector in an idiothetically correct position but the mutual shifts of the disk and belt eliminated the utility of local cues like scent marks for the idiothetic solution of the task. Purely allocentric orientation was required in a place recognition task in which pressing a lever mounted on a rotating arena was rewarded only when the operandum moved through an allocentrically defined 60 degrees segment of its trajectory. Place recognition was manifest by increased bar pressing rates on approach to and inside the reward zone. These methods may reveal how hippocampal place cell activity correlates with both allocentric and idiothetic aspects of spatial orientation.
Asunto(s)
Orientación/fisiología , Conducta Espacial/fisiología , Animales , Conducta Animal/fisiología , Estimulación Eléctrica , Electrodos Implantados , Planificación Ambiental , Privación de Alimentos , Hipocampo/fisiología , Aprendizaje/fisiología , Masculino , Actividad Motora/fisiología , Reconocimiento Visual de Modelos/fisiología , Ratas , Ratas Long-Evans , RotaciónRESUMEN
The PC is and will remain a basic instrument in the laboratory arsenal in the next few years. The key role of the IBM PC and its clones prompted us to develop a universal multifunctional I/O board (UNIMUL) for this computer. The board will make it possible to use the IBM PC for a wide range of tasks from a simple interface for laboratory processing of data to complex IBM PC-based instruments, e.g. a stimulator, signal analyzer, chart recorder. The present article summarizes the experience gathered during the design and application of the described I/O board in more than 10 different IBM PC-based laboratory and clinical systems listed in the Appendix. An example of the application of the I/O board is presented in the conclusion of this report together with the discussion of the future role of new Application-Specific Integration Circuits (ASICs) and single chip processors in this domain.
Asunto(s)
Sistemas de Computación , Informática Médica/instrumentación , Neurociencias/instrumentación , Investigación/instrumentación , MicrocomputadoresRESUMEN
Custom made hard and software enhancement of an IBM PC is described which makes it possible to: i) provide patterned visual stimulation by using the EGA or higher level display, ii) average recorded potentials and iii) monitor the experiment simultaneously. The description is illustrated by examples from a study of retinal evoked potentials in the rat.