SLC20A2 and Anxiety: To investigate the functional relevance of PiT-1 and PiT-2, we have subjected adult mice downregulated for either Slc20a1 or Slc20a2 in the HpC to a series of behavioral tasks to assess cognitive functions, namely spatial learning and memory (Morris Water Maze test, MWM), episodic memory (novel object recognition test, NOR), associative memory (contextual fear conditioning, CFC), and exploratory/anxiety-like behavior (open field test (OFT) and light/dark transition test (L/DT)) (Fig. 1E-G and S1G-I).