The prefrontal cortex (PFC) is known to be involved in working memory, executive control, attention, and decision making. It integrates internal information and states with external information from the environment which results in timely and appropriate behavioral responses. It remains unknown how distinct excitatory cell types within PFC contribute to population activity and behavior. We investigate two major excitatory cell types within the PFC - extratelencephalic (ET) and intratelencephalic (IT) neurons. Anatomical analysis in transgenic mouse lines shows that ET neurons project to subcortical structures while IT neurons project within the neocortex, to striatum and basolateral amygdala. We hypothesise that the two populations also differentially contribute to dynamic brain states (e.g.quiescence, arousal, and sleep) and behavior.To characterise the intrinsic properties and behavioral correlates of ET and IT populations within the PFC we conducted dense electrophysiological recordings in headfixed mice performing an auditory decision-making task. During the recordings we identified IT and ET neurons using optotagging, which renders neurons expressing opsins sensitive to light stimulation. IT and ET neurons demonstrate different responses to sound stimulation and during reward consumption. To directly investigate how prefrontal ET and IT neurons contribute to decision-making, we will next use inhibitory opsins and optogenetics to suppress the activity of the respective populations. Decision making has been found to be impaired in neuropsychiatric disorders such as autism spectrum disorder, and our investigations can potentially identify cell populations or neuronal projections that can be affected in such disorders.