NERVE GROWTH-FACTOR IMPROVES EVOKED-POTENTIALS AND LONG-TERM POTENTIATION IN THE DENTATE GYRUS OF PRESENILE RATS

Chronic infusion of nerve growth factor (NGF, 1.2 mu g/day) for 14 day s to presenile rats (17 months at the beginning of treatment) that sho wed an initial cognitive impairment led to an improved long-term poten tiation in the dentate gyrus. Both the relative increase of the slope of the population excitatory postsynaptic potential and that of the po pulation spike were enhanced by NGF pretreatment after long-term poten tiation induction at 400 Hz. The treatment was also able to increase t he diminished baseline amplitude of the population spike, an effect no t seen when the treatment was applied to older animals [Bergado, J., F emandez, C.I., Gomez-Soria, A., Gonzalez, O., 1997a. Chronic intravent ricular infusion with NGF improves LTP in old cognitively-impaired rat s. Brain Res. 770, 1-9] stressing the importance of an early start of trophic therapy to achieve better results. (C) 1998 Elsevier Science B .V.