Also this week MedZine brings you the latest medical news on various medical specialisms. In this editorial two striking studies are highlighted. The first study identifies the neuronal circuits in the spinal cord of mice that control the ability to produce the alternating movements of the legs during walking. The second shows that a liver protein has a critical role during pregnancy.
How the alternating movements of the legs during walking is generated
Most land animals can walk or run by alternating their left and right legs in different coordinated patterns. In a publication in Nature, Talpalar and colleagues identify two groups of nerve cells that control this movement. By using advanced genetic methods that allow the elimination of discrete groups of neurons from the spinal cord, they were able to remove a type of neurons characterized by the expression of the gene Dbx1. The Dbx1 gene was expressed in two distinct groups of neurons, one inhibitory and one excitatory. The mouse's alternating gait at low speeds is controlled by one group, while the other is activated when the animal moves faster. Removal of both populations of neurons prevents the mice from walking alternating and instead they move both hind limbs at the same time causing them to hop like rabbits.
The liver protein Lrh-1 is essential for sustaining pregnancy
Murphy and his group investigated mice that are deficient for liver receptor homolog-1 (Lrh-1). In a publication in Nature Medicine, the researchers show that this protein that is known to function in the liver also plays an important role during pregnancy. The mice lacking Lrh-1 are unable to create the uterine conditions needed for establishing and sustaining successful pregnancy. Previously, the researchers found a role for Lrh-1 in ovulation and these new data suggest that it play an important role in the uterus. In addition, Lrh-1 was found in the human uterus and plays a role in processes important for the success of early gestation. Hormone replacement therapy with progesterone did not restore normal uterine functions in the mice. There are new Lrh-1 agonists and antagonists, currently in clinical trials to treat hepatic consequences of type II diabetes, which might have an effect and are worth while investigating.
Sources: Eurekalert, Nature and Nature Medicine