Examining the effects of whisker trimming on mouse brain cell growth

Hoxb8 microglia are a particular breed of scavenger cells in the brain which have been related to obsessive compulsive disorder (OCD)-like behavior among other behavioral disorders. These cells have been found to reach full maturity during a period of neurological development known as the critical period. However, it has yet to be determined whether a correlation between the critical period and Hoxb8 microglial cell growth exists or if they are merely occurring at the same time due to unknown external factors. To better understand the extent to which the critical period plays a role in Hoxb8 microglial cell growth in mice brains, whisker trimming was conducted over four different periods of time. Whisker trimming was used as a source of manual sensory deprivation in order to lengthen the critical period in the tested mice brains. Given the direct connection between mice whiskers and the barrel field region of the brain, any resulting effects of manipulating the critical period on the density of Hoxb8 microglial cells would arise independently of outside factors in that particular region . Upon analysis of the barrel field regions of the brain for each mouse, it was found that whisker trimming from the eighth day after birth to the thirty-ninth day (P8-P39) produced a mean Hoxb8 microglial density 456% greater than was found in the control. Though this experiment serves as a preliminary study, the results provide insight into the connection between Hoxb8 microglia and the critical period. Furthermore, they simultaneously suggest the possibility of future applications in the use of manual sensory deprivation to control Hoxb8 microglial cell growth. Paired with further testing, the possibility of induced Hoxb8 microglial cell growth presents a possible treatment method for behavioral orders such as obsessive compulsive disorder through controlled sensory deprivation.