Environmental enrichment enhances directional selectivity of primary auditory cortical neurons in rats.

Environment enrichment (EE) has an important role in brain plasticity. Previous research has shown that EE increases the response strength of auditory cortical neurons, but it remains unknown whether EE can affect the directional selectivity of auditory neurons. In this study, rats were exposed to EE conditions during the developmental critical period (EE1) or after the critical period (EE2). By in vivo extracellular recording, we found that EE enhanced the directional selectivity of primary auditory cortical neurons in EE1 rats, which showed a sharper azimuth selectivity curve of auditory cortical neurons compared with normal rats. However, there was no significant difference in directional selectivity between the EE2 rats and age-matched control rats. Our findings indicate that early exposure to EE enhances the directional sensitivity of primary auditory cortical neurons. These results provide an insight into developmental plasticity in the auditory system.