Foetal motor neuron imbalance can hard-wire later problems, researchers say

Motor neuron connections are refined in the weeks before and just after birth, and they are crucial for normal development later, University of Queensland research suggests. The discovery could lead to a better understanding of developmental disorders such as autism and epilepsy, say two School of Biomedical Sciences neuroscientists, Associate Professors Peter Noakes and Mark Bellingham. "Motor neurons form a direct connection between the nervous system and the muscles," Dr Bellingham said. "It has been well established previously that it is vital that motor neurons do not become over-excited during critical foetal and neonatal periods." The neuroscientists made the discovery about the importance of the weeks before and after birth during research into the motor neurons that control breathing. "This intricate balance during respiratory motor system development is particularly important because it's vital that breathing begins at the moment of birth," Dr Bellingham said. "When the neural circuits are put together in foetal development, all neurotransmitters in the brain and spinal cord act as excitatory influences on motor neurons. "Our research using a mouse model found that glycine prevented respiratory motor neurons from becoming 'over-excited' in the crucial final trimester of pregnancy when they are connecting with their target muscles.