Presynaptic dysfunction in neurodevelopmental disorders

We have recently identified the first human mutation in synaptotagmin-1 (Syt1), in a child with a severe neurodevelopmental disorder. The child harbouring this mutation displayed profound intellectual disability, delayed motor development, and severe neurophysiological disturbance, but MRI revealed no structural brain abnormality. This mutation (I368T) occurs in a highly conserved residue in Syt1. We examined the effect of I368T Syt1 on presynaptic activity, and found that the presence of this mutant variant of Syt1 in neurons resulted in altered synaptic vesicle recycling dynamics.

We have now identified a further 5 mutations in Syt1, in individuals who have symptoms that largely overlap with our index case, but with differing degrees of severity. Intriguingly, mutations in the related protein, synaptotagmin-2, cause a neuromuscular disorder which is treatable.

Aims

  • Investigate how mutations in Syt1 affect the synaptic vesicle cycle, and whether these effects are treatable.
  • Examine whether all Syt1 mutations cause the same alterations to neurotransmitter release dynamics, thereby determining the molecular mechanisms underlying neurodevelopmental disorders in individuals harbouring these mutations.
  • Investigate whether pharmacological intervention with this same drug can at least partially overcome some of the deficits caused by mutations in Syt1.

Neurodevelopmental disorders are a devastating group of conditions characterised by developmental impairments, which usually manifest in infants and children. These disorders can result in a broad range of deficits, including learning delay and intellectual disability, problems with muscle control and movement, and behavioural and emotional issues. In severe cases the affected individuals may require lifetime care and/or have a reduced life expectancy.

Gene technology is now enabling the identification of many novel causes of neurodevelopmental disorder. This provides a new starting point for understanding the relationships between specific genetic mutations, brain function and development, cognition and mental health. There is growing evidence that the machinery that controls the release of neurotransmitters is compromised in a range of neurodevelopmental disorders, including intellectual disability, epilepsy, and autism spectrum disorders.

This project will implement a variety of techniques including

  • Molecular biology
  • Biochemistry
  • Primary neuronal cell culture
  • Fixed immunofluorescence imaging and live-cell fluorescent imaging

This will give students the opportunity to master a range of key transferable skills.

Take part in this project

Student applications

Students who are applying to study at The Florey can register their interest in this project. Refer to our step-by-step guide to help you with your application.

How to apply

Accepting students

Contact us

If you’re interested in learning more about this project please contact our team.

Please enter your first name
Please enter your last name
Please enter a valid phone number
Please enter a correct email address
Please provide information regarding your enquiry