It’s brain awareness week!

Hello all!  I wanted to take a few minutes to write something for the brain awareness week. This is important to me because my research focusses on understanding the role of the immune system in the brain. For a very long time, the brain was thought to be an “immune privileged” organ i.e., it was thought that the brain is protected from all the peripheral insults and that it is “divorced” from the rest of the body. In 2015, it was shown that there exists certain lymphatic vessels that connect the CNS to the rest of the body (1). The lymphatic system carries immune cells through a network of vessels and tissues; it connects the bloodstream and tissues in order to remove dead cells and other debris. The discovery of the new “glymphatic system” has opened new avenues to study the connection between the brain and the rest of the body. This is especially helpful in understanding the role of the peripheral immune system on the CNS during infections, injury, and other disease insults.

glymphatic system
Old lymphatic system (left) and newly discovered lymphatic system in the CNS (right). Source: University of Virginia Health System

My work focusses on a specific cell type in the brain known as microglia which are are the resident macrophages of the CNS (they eat up and clear out the bad stuff in the brain like dead cells and mis-folded proteins). Microglia are the only known immune cells of the brain. Compared to all that’s known about the cells of our body’s immune system (B cells, T cells, NK cells, neutrophils, basophils, Treg cells, MDSCs, TH1, TH2, and many many more with several subtypes of each cell), it is safe to say that cells of the CNS are poorly understood. My efforts are focussed towards understanding the role of microglial cells in neurodegenerative diseases such as Alzheimer’s Diseases (AD) , Parkinson’s Disease (PD), Multiple Sclerosis (MS), etcetera. These diseases are characterized by mis-folded proteins that aggregate in the different regions of the brain tissues causing the neurons to degenerate and eventually die. The microglial cells in these disorders play a major role in disease progression by regulating many pathways involved in cell-cell communication, cell survival, and cell death. This is a relatively new and an exciting area of study with many missing links and questions to be answered. I will try my best to keep this space alive with updates and stories! In the meantime, here’s a fun read on Leonardo da Vinci’s contributions to neuroscience:

And here’s a 1504-1506 drawing of the human brain by da Vinci:

Leonardo da Vinci's contributions to neuroscience
In the upper figure, the three ventricles are labeled imprensiva (anterior ventricle, corresponding to the paired lateral ventricles), senso comune (third ventricle), and memoria (posterior or fourth ventricle). Below the ventricles, seven pairs of cranial nerves are shown. The lower figure shows a human head in an exploded view, with the skull raised over the brain and from the head. Source: 


  1. Louveau A, et al. Structural and functional features of central nervous system lymphatic vessels. Nature. 2015;523(7560):337–341. doi: 10.1038/nature14432.