This is a laboratory rat with a brain implant, that was used to record in vivo neuronal activity during a particular task (discrimination of different vibrations). On this picture scientist feeds the rat apple juice through a pipette.
<a href="//commons.wikimedia.org/w/index.php?title=User:Anna_Marchenkova&amp;action=edit&amp;redlink=1" class="new" title="User:Anna Marchenkova (page does not exist)">Anna Marchenkova</a>
CC BY 4.0
<span class="int-own-work" lang="en">Own work</span>