SYN1 and depressive symptom measurement: Despite not differentiating cell subtypes, Bessa et al. (2013) showed MSNs hypertrophy in the NAc and increased NAc expression of Bdnf, neural cell adhesion molecule 1 (Ncam1), and synapsin 1 (Syn1) – all known to be related to neuroplasticity - of rats displaying stress-induced anhedonia behavior, a core symptom of depression.