EXOGENOUS NGF AFFECTS CHOLINERGIC TRANSMITTER FUNCTION AND Y-MAZE BEHAVIOR IN AGED FISCHER 344 MALE-RATS

Chronic ICV administration of NGF stimulates the activity of the cholinergic neuronal markers, HACU and ChAT, as well as the evoked release of both endogenous and newly synthesized acetylcholine in the brain of aging Fischer 344 male rats. However, the pattern of cholinergic phenotype stimulation indicates an age-related differential regulation of ChAT, HACU, and ACh release between specific brain areas, with the largest effects found in the striatum. NGF treatment also increases the effectiveness of neurotransmission between basal forebrain cholinergic neurons and postsynaptic amygdaloid target neurons. The stimulation of central cholinergic transmitter function after NGF treatment affects behavior in a Y-maze brightness discrimination paradigm. NGF treatment does not affect the cognitive measure of brightness discrimination, but reduces the number of avoidance attempts, a measure of motor function.