The Meucci lab recently published a new study suggesting that learning and memory problems in patients with HIV-associated neurocognitive disorders (HAND) may be reversible. Using an animal model of HAND, Dr. Lindsay Festa and colleagues showed that treatment with the chemokine CXCL12 improved cognitive flexibility in a set-shifting task and increased dendritic spine density in the layer II/III prefrontal cortex, a critical brain area for flexible problem solving. CXCL12 treatment achieved these effects by activating a molecular signaling cascade via the small GTPase Rac1, which stabilized thin dendritic spines on cortical neurons. The study shows that CXCL12 reverses cognitive impairment in an animal model of HAND, suggesting that new treatments for HAND could exploit the CXCL12/Rac1 pathway in the brain.
This study is open access and freely available at eLIFE.