Platelet-derived nerve growth factor supports the survival of cholinergic neurons in organotypic rat brain slices

• Platelets contain endogenous nerve growth factor (NGF).
• Platelets can be loaded with recombinant NGF using ultrasound.
• Platelet-derived NGF supports survival of cholinergic neurons in brain slices.

Platelets play a role in repair of vessels and contain different growth factors, including nerve growth factor (NGF). Since NGF is the most potent growth factor to support survival of cholinergic neurons, we aimed to study the effects of platelet-derived NGF on cholinergic neurons in organotypic brain slices. Brain slices of the nucleus basalis of Meynert (nBM) were cultured with or without NGF (10 ng/ml) or platelet extracts (100 μg/ml) or fresh platelets (108 platelets/ml). In order to enhance NGF in platelets recombinant NGF (100 ng) was loaded into platelets using ultrasound (3 h). Our data show that recombinant NGF markedly supports survival of cholinergic neurons. The addition of fresh platelets showed a tendency for enhancing cholinergic neuron numbers, while platelet extracts had no effects. Ultrasound was highly effective to load recombinant NGF into platelets. The addition of NGF-loaded platelets markedly enhanced cholinergic neuron numbers. In conclusion, our data provide evidence that NGF-derived platelets may counteract cell death of cholinergic neurons.