A rare variation of superior rectus muscle.

The extraocular muscles are responsible for all eye movements required to track and fix objects. Superior rectus muscle is located in the superior level of the orbital cavity, below musculus levator palpebrae superioris, tilted slightly to the lateral part of the orbit. In a routine dissection, we found a left, unilateral variation of the superior rectus muscle with no variation in other structures, such as nerves and vessels.

H3 acetylation selectively promotes basal progenitor proliferation and neocortex expansion.

Increase in the size of human neocortex―acquired in evolution―accounts for the unique cognitive capacity of humans. This expansion reflects the evolutionarily enhanced proliferative ability of basal progenitors (BPs), including the basal radial glia and basal intermediate progenitors (bIPs) in mammalian cortex, which may have been acquired through epigenetic alterations in BPs. However, how the epigenome in BPs differs across species is not known.