Synchron Inc. raised $200 million to advance its work building brain implants that doctors can insert through blood vessels, avoiding the costly and high-risk surgeries necessary to install devices made by other rival companies like Elon Musk’s Neuralink.With the new funds, the company’s valuation is nearly $1 billion, a Synchron spokesperson said. That makes it the second-most valuable brain implant company after Neuralink, which investors think is worth more than $9 billion....