This study showcases the Smart Neurostimulation System (SNS), a 60-channel, wireless, implantable brain-computer interface designed for closed-loop treatment of memory disorders. In a chronic study of three sheep, the SNS demonstrated stable performance across three core functions. First, the SNS reliably decoded neural states, classifying movement from stillness with high accuracy (AUC 0.92 - 0.98). Second, the stimulation with the SNS produced dose-depended changes in alpha- and gamma-band neural activity, confirming that stimulation reliably modulates physiological signals. Finally, this study confirms the SNS's positive biocompatibility profile, with no adverse tissue response reported and findings comparable to a commercially available control lead..