MAPT and Apathy: These results suggest that MAPT, MAPTInt10+3 and MAPTS305N;Int10+3 KI mice show behavioral disinhibition, described as ‘impulsive, rash or careless actions47.’ The taste preference and effort-based choice test, using saccharin dissolved or plain water as rewards of different value, was conducted to assess anhedonia and/or apathy-like behavioral signs.