MECHANISM OF ALTERED SYNAPTIC STRENGTH DUE TO EXPERIENCE - RELATION TO LONG-TERM POTENTIATION

An increase in medial perforant synaptic strength can be observed for hippocampal slices from rats exposed to environmental enrichment. The expression of enhanced synaptic strength exhibits properties similar t o long-term potentiation (LTP), a physiological model of memory storag e. Similarities include an increase in strength of the synaptic respon se in the absence of an altered paired-pulse ratio and an increase in the binding of the glutamate agonist ha-amino-3-hydroxy-5-methyl-4-iso xazolepropionate. Furthermore, environmental enrichment interacts with the mechanisms responsible for the induction of LTP by inhibiting fur ther increases in synaptic strength following LTP-inducing stimulation . The results provide evidence for experience-mediated influences on p ostsynaptic mechanisms regulating medial perforant path synaptic stren gth.