This study investigates the effect of nerve growth factor (NGF) on the survival of cholinergic neurons in the septo-hippocampal pathway after fimbrial transection in adult rats. The fimbria, which connects the septum to the hippocampus, was unilaterally transected, and animals were treated with NGF or a control protein intraventricularly over 4 weeks. The results showed that fimbrial transection led to a significant reduction in the number of large cell bodies and AChE-positive cholinergic neurons in the medial septal nucleus and the vertical limb of the diagonal band of Broca. However, chronic NGF treatment significantly attenuated this degeneration, reducing the reduction in AChE-positive cells to only 12% compared to control levels. These findings suggest that NGF can promote the survival of cholinergic neurons after axonal injury, potentially offering a therapeutic approach for conditions like Alzheimer's disease, where selective loss of cholinergic neurons is a key factor.This study investigates the effect of nerve growth factor (NGF) on the survival of cholinergic neurons in the septo-hippocampal pathway after fimbrial transection in adult rats. The fimbria, which connects the septum to the hippocampus, was unilaterally transected, and animals were treated with NGF or a control protein intraventricularly over 4 weeks. The results showed that fimbrial transection led to a significant reduction in the number of large cell bodies and AChE-positive cholinergic neurons in the medial septal nucleus and the vertical limb of the diagonal band of Broca. However, chronic NGF treatment significantly attenuated this degeneration, reducing the reduction in AChE-positive cells to only 12% compared to control levels. These findings suggest that NGF can promote the survival of cholinergic neurons after axonal injury, potentially offering a therapeutic approach for conditions like Alzheimer's disease, where selective loss of cholinergic neurons is a key factor.