Welcome to the Asahina lab
The male Drosophila brain (grey) and neurons that control aggressive behavior (green). Only 3-4 pairs of these neurons exert significant behavioral change to the fly.

The nervous system is constantly performing amazing tasks, such as sensing the surrounding environment, recognizing other individual’s actions, and choosing a proper behavior, often in the order of subseconds. Ethologists have long noticed that animal behavior is variable – that is, the same sensory stimuli do not necessarily trigger the same behavioral reactions. Something inside the animal must have changed, and this something, or an internal state, is generated by the nervous system. Growing evidence suggests that an animal’s internal state often shows neuronal and genetic parallels to human emotional and motivational states. Failure in the appropriate control of such states can cause various types of mental and psychiatric disorders, including depression, stress and anxiety disorders, and eating disorders.

Our laboratory is interested in understanding the genetic and neuronal basis of internal states. We take advantage of the powerful genetic resources of the vinegar fly, Drosophila melanogaster, to identify molecular events that influence the operation of neural circuits that ultimately control behavior. Integrating molecular genetic tools with neurophysiology, we can cut across the layered complexity of the neural mechanisms controlling animal behavior. Our long-term goal is to illuminate the fundamental principles underlying the generation and maintenance of internal states that is common to all animal species. Such understanding will help us identify what goes wrong with pathological brains, and develop more effective and specific medical treatments for mental illnesses associated with problems in emotional and motivational control. To this end, we are employing a combination of the latest technologies in genetics and neuroscience, including CRISPR/Cas9 genome editing, manipulation of specific neural populations, 2-photon functional imaging, and machine vision-assisted behavioral analyses. These technologies allow us to manipulate, observe and characterize molecular and cellular dynamics of the nervous system.