Fig. 3:

Synaptic loss and cognitive impairment induced by HIV proteins can be pharmacologically reversed. Infusion of HIV Tat into the lateral ventricle decreased spine density in the retrosplenial cortex and impaired cognitive function. A single infusion of Tat produced a prolonged decrease in spines (horizontal red arrow). Spines lost during Tat exposure are shown in red at baseline. Systemic administration of ifenprodil (blue horizontal bar) rescued spines (new spines are blue) and cognitive function. Note that after clearance of ifenprodil spine density and cognitive function returned to levels observed before drug administration. Figure modified from [32].