Research

On-going research topic

Neuromodulators in flexible decision making (w/ K. Svoboda, J.Y. Cohen)
Flexible decision making in dynamically changing environment is a crucial cognitive function for survival. Also, storing and evaluating action/outcome history supports better decisions in the future. Our research aims to reveal roles of neuromodulators, in particular mono-amines, in decision making and working memory. 

Previous research topics

1. Activity-dependent gene expression in learning and memory (w/ A. Lüthi)
Activity-dependent gene expression bridges the gap between animal experiences and neuronal plasticity underlying learning and memory. Our research focuses on the roles of learning-dependent immediate-early gene expression in the basolateral amygdala (Hagihara, Karalis, and Lüthi, in preparation).

2. Dissecting amygdala circuits underlying fear and extinction (w/ A. Lüthi, A. Holmes)
The amygdala and prefrontal cortical areas have been know to be important for fear and its extinction. However, how such distributed brain areas work in concert had not been well understood. By establishing novel optical/histological approaches, we identified a new circuit motif that orchestrates those multiple brain areas controlling behavioral state of the animal (Hagihara#, Bukalo#,et al., 2021). In addition, we identified di-synaptic projection specificity in a BLA-CeA-vlPAG circuit that enables fear learning and expression (Massi#, Hagihara#, et al., 2023).

3. Functional organization and development of the mouse visual system (w/ K. Ohki, Y. Tagawa)
Neuronal activity is indispensable for normal development of neuronal circuit and function. But how?
We established developmental stage-specific neuronal activity manipulation methods and revealed activity-dependent and activity-independent components of visual selectivity maturation (Hagihara et al.,2015), and development of long-range callosal-projections have a specific "critical period" when spontaneous activity contributes to their maturation (Tezuka#, Hagihara#, et al., 2022). In addition, we found that callosal-projection neurons in the visual cortex show distinct response properties and fine-scale local subnetworks (Hagihara#, Ishikawa#, et al., 2021).