In an earlier study, our group had shown that, in the R6/2 mouse of HD, the beneficial effects exerted by phosphodiesterase inhibitors on phenotype and on projection neurons sparing was associated to a rescue of parvalbumin positive interneurons and to an inhibition of CBP sequestration into NIIs (Giampà et al., 2009). The gene discussed is PVALB; the disease is Huntington disease.