One of the first chambers Riker passes inside the Daystrom facility holds a Genesis device, as seen in Star Trek II: The Wrath of Khan (1982).
Irumodic Syndrome is a type of neurodegenerative condition, similar to dementia. Picard suffered from this syndrome in the future of an alternate timeline that he experienced because of Q in the series finale All Good Things... (1994). Picard learns that this alternate future he experienced is just one possible future, and that he is the only one with memories of this alternate timeline. When he returns to the present, he asks Crusher to test him for Irumodic Syndrome. She does and tells him that he does not have it, but that he does carry the gene defect that causes the syndrome and that it's possible he could develop the syndrome at some point, but that it is also possible he could live the rest of his life without developing it.
When Seven and Jack are looking at the museum ships, the themes from Star Trek: Deep Space Nine (1993), Star Trek (1966), Star Trek: Voyager (1995), and Star Trek IV: The Voyage Home (1986) play as they view the Defiant, Enterprise-A, Voyager, and Bounty, respectively.
One of the doors seen inside the Daystrom facility is labeled "James T. Kirk", implying that Kirk's remains, following the events of Star Trek: Generations (1994), are stored inside.
The Fleet Museum at Athan Prime (curated by Commodore Geordi LaForge) includes the starships USS Enterprise (NCC-1701-A), USS New Jersey (NCC-1975), USS Defiant (NCC-75633), USS Voyager (NCC-74656), a Klingon D-7 battle cruiser, and the Klingon bird-of-prey "HMS Bounty" from Star Trek IV: The Voyage Home (1986). Additional ships listed in the registry (seen in the closing credits) include the USS Excelsior (NCC-2000) and USS Pioneer (NCC-1500).