BEHAVIORAL FUNCTION OF THE HIPPOCAMPUS IN ASSOCIATIVE LEARNING.

Research Project

Project/Area Number	60450013
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	Psychology
Research Institution	Kyoto University
Principal Investigator	HIRANO TOSHITSUGU FACULTY OF LETTERS, KYOTO UNIVERSITY, 文学部, 教授 (50046869)
Co-Investigator(Kenkyū-buntansha)	AKASE EISUKE FACULTY OF LETTERS, KYOTO UNIVERSITY HIRANO TOSHITSUGU FACULTY OF LETTERS, KYOTO UNIVERSITY YAMAGUCHI MASAHIRO FACULTY OF LETTERS, KYOTO UNIVERSITY (30191240)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥5,900,000 (Direct Cost: ¥5,900,000) Fiscal Year 1986: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 1985: ¥5,200,000 (Direct Cost: ¥5,200,000)
Keywords	Reinforcement-nonreinforcement / Alternation learning / hippocampus / Operant response / オペラント反応 / シロネズミ
Research Abstract	TO EVALUATE THE EFFECTS OF A SINGLE ALTERNATION PARADIGM ON HIPPOCAMPAL UNIT ACTIVITY, ALTERNATION PARADIGM ON HIPPOCAMPAL UNIT ACTIVITY, ALTERNATING GO/NO-GO TRAINING WAS GIVEN TO THE RAT. AS A PRELIMINARY TRAINING, SHAPING OF ANIMALS TO A LEVER PRESS FOR PELLETS WAS CONDUCTED ON CRF SCHEDULE. THE SINGLE ALTERNATION WAS STARTED ON THE DAY FOLLOWING COMPLETION OF THE PRELIMINARY TRAINING. EACH ANIMAL RECEIVED 240 REINFORCED AND 240 NONREINFORCED TRIALS PER DAY FOR 3 TO 7 DAYS. EACH TRIAL CONSISTED OF A PRESENTATION OF TONE OF 1 SEC, FOLLOWED BY A 10SEC PRESENTATION OF A RETRACTABLE LEVER AFTER 0.5 SEC FROM THE ONSET OF THE SIGNAL. EACH TRIAL WAS FOLLOWED BY A VARIABLE INTERTRIAL INTERVAL DURING WHICH THE LEVER WAS RETRACTED. ON THE ODD NUMBERED TRIALS THE RATS WERE REINFORCED AND ON THE EVEN NUMBERED TRIALS THEY WERE NOT REINFORCED. THE LATENCY FROM THE ONSET OF THE AND ON THE EVEN NUMBERED TRIALS THEY WERE NOT REINFORCED. THE LATENCY FROM THE ONSET OF THE TONE TO THE LEVER PRESS WAS R … More ECORDED. PRIOR TO AND DURING THE TONE PRESENTATION, HIPPOCAMPAL UNITS AND ANIMAL'S MOVEMENT WERE RECORDED. THE RESULTS OF THE EXPERIMENT SHOWED THAT ANIMALS DEVELOPED DIFFERENTIAL LATENCY TO THE LEVER PRESS, WITH LONGER LATENCY TO THE NON-REINFORCED TRIALS. CORRELATED WITH THIS ACQUISITION, ANIMALS COULD DIFFERENTIATE THE MOVEMENT PATTERN TO THE SIGNAL WHICH NOTICED THE LEVER PRESENTATION. HIPPOCAMPAL UNITS ALSO REVEALED DIFFERENTIAL RESPONSE TO THE SIGNAL WITH GREATER ENHANCEMENT TO THE REINFORCED TRIALS THAN THE NONREINFORCED TRIALS AT THE EARLY STAGE OF THE LEARNING. THE LEVEL OF THE HIPPOCAMPAL ACTIVITY BEFORE THE SIGNAL PRESENTATION EXHIBITED DIFFERENCES BETWEEN THE REINFORCED AND NONREINFORCED TRIALS AT AN EARLY STAGE OF THE ALTERNATION TRAINING, AND DISAPPEARED IN THE FOLLOWING PERIODS. THE RESULTS SUGGEST HIPPOCAMPAL FUNCTION AS PROCESSING OF WORKING MEMORY OF THE PRECEDING TRIALS AT AN EARLY STAGE OF THE ALTERNATION LEARNING IN PARTICULAR, FOLLOWED BY SHORTEND INTERVALS FOR THE PROCESSING BASED ON THE DEVELOPMENT OF AUTOMATIC PATTERNING BEHAVIOR. Less