Hebbian Plasticity in the Hippocampus: Involvement of Protein Phosphorylation and Protein Kinase C
G. M. J. Ramakers I. J. A. Urban P. N. E. de Graan W. H. Gispen Rudolph Magnus Institute University of Utrecht
During the last two decades a strong scientific interaction developed between the laboratory of Bob Isaacson and the Department of Medical Pharmacology of the Rudolf Magnus Institute. Although for years the neural mechanisms of grooming behavior of rats were a focal point in that collaboration, the neurobiology of learning and memory processes with special reference to the role of the hippocampus was and is a subject that is actively researched by both teams of investigators. In this chapter, we review some aspects of hippocampal synaptic plasticity presumed to be of significance to learning and memory processes.
During the course of this century, tremendous insight has been gained into how the nervous system and the brain are organized and how neuronal circuits respond to external and internal stimuli. A major question was and still is how experience is acquired and stored. There is little doubt that learning and memory are aspects of brain function. However, there is still much debate as to where and how these processes take place. Most of our current thinking is influenced by the hypothesis put forward by D. Hebb in the 1940s that the basis for memory consolidation lies in functional modifications of the junctions between neurons, the synapses. It was suggested that the efficacy of communication between two neurons is related to the degree of activation and previous experience. It took approximately 30 years to obtain experimental support for this important notion.
The first reports of an activity-dependent increase in synaptic transmission were from Lomo ( 1966), and the first systematic reports were from