TAT and Cognitive impairment: Injection of recombinant Tat protein alone is an attractive and relevant feature of our model, since cognitive impairment can occur despite minimal viral load [14], [15], [21], while many viral factors would not be present; commonly attributed to low-level viral replication that occurs even with the most effective anti-retroviral regimens [16]–[19], [21] giving rise to early pro-inflammatory viral proteins, such as Tat, that persist even in the presence of cART [80].