We assessed firing and voltage-gated Ca2+ influx in medial prefrontal cortex (mPFC) pyramidal neurons from older (12 months old) HIV-1 transgenic (Tg) rats. We found that neurons from older Tg rats showed increased firing compared to non-Tg rats, but Ca2+ spikes were unchanged. However, stronger excitatory stimulation was needed to evoke Ca2+ spikes, which was associated with reduced mPFC Cav1.2 L-type Ca2+ channel (L-channel) protein. In contrast, L-channel protein was unaltered in younger (6-7 weeks old) Tg rats, which we previously found had enhanced neuronal Ca2+ influx. These studies demonstrate that aging alters HIV-induced Ca2+ channel dysfunction that affects mPFC activity.
Keywords: Calcium; HAND; HIV; HIV-1 Tg rat; L-channel; Medial prefrontal cortex.