Neurobiology of Sleep-Wakefulness Cycle 2(1): 6-20, 2002
Printed in Georgia. All rights reserved.
2002 NSWC

THE INFLUENCE OF REVERSIBLE FUNCTIONAL INACTIVATION OF HIPPOCAMPUS ON THE ELABORATION OF SPATIAL SOUND DISCRIMINATION IN CATS

N. Nachkebia, N. Lortkipanidze, T. Oniani, A. Nachkebia, E. Ckhartishvili

Department of Neurobiology of Sleep-Wakefulness Cycle, I.S. Beritashvili Institute of Physiology, Georgian Academy of Sciences, Tbilisi

Accepted in revised form 25 March 2002; recieved 16 November 2001.

Summary

The investigation of the role of hippocampus in the elaboration of instrumental spatial sound discrimination to two feeders, in the many trial test, was carried out in cats. The procedure of experiments was conducted so, that the main attention was devoted to the clearing of significance of this structure in the consolidation of acquired information. To this aim a comparison of control animals was made to experimental ones, in which a reversible functional inactivation (RFI) of hippocampus by means of repetitive local epileptiform discharges were induced: (a) - before the onset of daily series of elaboration - proactive RFI, (b) - after the end of daily series of elaboration - retroactive RFI, (c) - with 1 min interval after each pairing of conditioned and unconditioned signals, (d) - with 25 sec interval after each pairing, (e) - just immediately after the each pairing. The results of these series of experiments were different; in the case of (a) and (b) the dynamic of elaboration of spatial task was approximately the same as in control animals, but in the case of (c), (d), (e) a significant enhancement of spatial discrimination learning was evident. A critical participation of hippocampus in the consolidation of memory traces is questioned and the possible significance of this structure in the short -term process, which precedes the consolidation of acquired information, is discussed.

Key Words: hippocampus, functional inactivation, consolidation, memory formation.


Correspondence: Nachkebia Nargiza, Dr.,
Department of Neurobiology of Sleep-Wakefulness Cycle,
I.S. Beritashvili Institute of Physiology, Georgian Academy of Sciences,
14, L. Gotua str., Tbilisi, 380060, Georgia.
E-mail: nswc@neurobiology.ge