Hi Samir,
They certainly can.
Neo4j is ACID-compliant and can participate in XA transactions with supported
JDBC connections and/or any other XA resource (JMS connections...)
If you use Spring Framework, Neo4j can participate in transactions using @Transactional annotation as well.
For more details you can take a look at Chris Gioran's blog (a bit old, but still valid in Neo4j XA space):
http://digitalstain.blogspot.co.uk/2010/10/neo4j-internals-transactions-part-2.html
Aleksa