Blood supply to brain and placenta in the capybara

Capybara (Hydrochoeris hydrochaeris)
Wikimedia Commons

The current issue of Science (here) draws attention to recent work on the blood supply to the brain in capybaras. As in other mammals young capybaras have a dual supply from the internal carotid arteries and the basilar artery. At one year of age, however, remodelling of the internal carotid shuts down that source and the basilar artery becomes the sole source of blood to the brain. Research on the underlying mechanisms is being conducted at the Department of Surgery at the Veterinary School in Sao Paulo (here).

The Department is also home to a vibrant research group led by Angelica Miglino with whom it has been my privilege to collaborate on the blood supply to the capybara placenta (here and here).

Placentation in the capybara from Kanashiro et al.
Reprod Biol Endocrinol 2009 (here)

Like other hystricognath rodents, capybaras have a discoid, labyrinthine, haemochorial placenta with an inverted yolk sac that persists to term. An additional feature shared with other hystricognaths is the subplacenta (sub in panel D above). With Claudia Kanashiro we published a detailed study of this structure in the capybara (here). 

It is encouraging to see Science advocate the capybara as a model for stroke. In view of its size - at around 65 kg it is the largest living rodent - it might be useful as a model for fetal physiology. As shown in a previous post on the guinea pig, hystricognaths have precocial young and are in this respect more satisfactory models for gestation than mice and their kin.