Not only that, but there is evidence that in a lot of brain regions neurons simply connect to whatever cells they touch with the average topology of any region defined by the growth properties of the cell types that exist there. From there, the individual connection strengths are reinforced or worn away or otherwise altered by actual neural activity via changes in membrane, cytoskeleton, kinase, etc activity/​composition at the individual synapse (on both sides).
Not only that, but there is evidence that in a lot of brain regions neurons simply connect to whatever cells they touch with the average topology of any region defined by the growth properties of the cell types that exist there. From there, the individual connection strengths are reinforced or worn away or otherwise altered by actual neural activity via changes in membrane, cytoskeleton, kinase, etc activity/​composition at the individual synapse (on both sides).