Neurological Questions

A specific subgroup of neurons (termed AC→BLA cells) in auditory cortex (AC) projects to basolateral amygdala (BLA), Dr. Joy wants to know whether the AC→BLA neurons are glutamatergic or GABAergic neurons. According to what we learned today, what strategy should Joy use to reveal that?

Dr. Ray works with Dr. Joy, Ray wants to investigate the functions of these AC→BLA cells in fear conditioning. So she injected retrograde AAV-hM3Dq in basolateral amygdala to label the AC→BLA cells in auditory cortex, a month later, she was trying to perform the fear conditioning task by injecting mice with CNO (clozapine N-oxide, which will work on hM3Dq and activate the neurons). However, after she injected CNO intraperitoneally, she noticed that the mice were very anxious even without any fear conditioning, which is abnormal, what might be wrong? What is the right way to investigate AC→BLA neuron’s functions?