Tracking memory's trace
AUTOR(ES)
Horn, Gabriel
FONTE
The National Academy of Sciences
RESUMO
There is strong converging evidence that the intermediate and medial part of the hyperstriatum ventrale of the chick brain is a memory store for information acquired through the learning process of imprinting. Neurons in this memory system come, through imprinting, to respond selectively to the imprinting stimulus (IS) neurons and so possess the properties of a memory trace. Therefore, the responses of the intermediate and medial part of the hyperstriatum ventrale neurons to a visual imprinting stimulus were determined before, during, and after training. Of the total recorded population, the proportions of IS neurons shortly after each of two 1-h training sessions were significantly higher (approximately 2 times) than the pretraining proportion. However, ≈4.5 h later this proportion had fallen significantly and did not differ significantly from the pretraining proportion. Nevertheless, ≈21.5 h after the end of training, the proportion of IS neurons was at its highest (approximately 3 times the pretraining level). No significant fluctuations occurred in the proportions of neurons responding to the alternative stimulus. In addition, nonmonotonic changes were found commonly in the activity of 230 of the neurons tracked individually from before training to shortly after the end of training. Thus the pattern of change in responsiveness both at the population level and at the level of individual neurons was highly nonmonotonic. Such a pattern of change is not consistent with simple models of memory based on synaptic strengthening to asymptote. A model is proposed that accounts for the changes in the population responses to the imprinting stimulus in terms of changes in the responses of individual neurons.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=33201Documentos Relacionados
- Memory's echo: Vivid remembering reactivates sensory-specific cortex
- STUDIES ON MEMORY: EVIDENCE FOR A WIDESPREAD MEMORY TRACE IN THE NEOCORTEX AFTER THE SUPPRESSION OF RECENT MEMORY OF PUROMYCIN*
- Some Evidence for the Involvement of Adrenergic Sites in the Memory Trace*
- Initial localization of the memory trace for a basic form of learning.
- Short term memory may be the depletion of the readily releasable pool of presynaptic neurotransmitter vesicles of a metastable long term memory trace pattern