Year: 2014
Type: dissertation
Abstract: Two distinct hippocampal oscillatory states have been associated to functions in learning and memory.Theta oscillations (3 -12 Hz) occurring during attentive exploratory behaviors are suggested to reflect the formation of new memory traces to the hippocampus.In a complementary function, sharp-wave ripples (~200 Hz) occurring during slow wave sleep and quiet restfulness, are essential for memory consolidation.There is experimental evidence that presenting learning trials contingent to theta oscillation enhances learning.The effects of ripple contingent training are unknown, but should be expected to result in slower learning.Rabbits were trained with trace eyeblink conditioning and extinction contingent to hippocampal ripple states, while a yoked control group was trained simultaneously independent of their neural state.Contrary to what was expected ripple contingent training accelerated acquisition of the conditioned response, but slowed down extinction.The results are suggested to be explained by hippocampal oscillatory state dependent properties of neuromodulator systems that have different effects on conditioning and extinction.
Author: Pekka Raussi
Language: English
Topic: Memory and Neural Mechanisms
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2336756750