Download APPLICATION FOR MRC STUDENTSHIPS TO COMMENCE 2009

PhD Project Title: Transcriptional control of the specification and function of ventral
tegmental area dopamine neurons
Supervisors: Dr Lia Panman and Professor Giovanna Mallucci
Aims:
This studentship will investigate how ventral tegmental area dopamine neurons are specified during
development and how its dysfunction is associated with neurodevelopmental disorders including
ADHD and Schizophrenia. The study will focus on the function of the transcription factor Nolz1 in
the specification and function of ventral tegmental area (VTA) dopamine neurons during embryonic
development using mouse and embryonic stem (ES) cell models. We will overexpress Nolz1 to
direct the differentiation of ES cells towards VTA neurons. These homogeneous cultures of VTA
dopamine neurons will be used to model VTA neuron associated diseases in vitro.
Background:
Midbrain dopamine (mDA) neurons constitute a highly diverse neuronal population controlling
important brain functions, such as motor action, cognition, motivation, reward and emotions. mDA
neurons can be broadly subdivided into three groups, which form the substantia nigra (SN), ventral
tegmental area (VTA) and the retrorubral field (RRF). SN dopamine neurons innervate the
dorsal/lateral part of the striatum and control motor action, while VTA neurons regulate
mesolimbic and mesocortical pathways. The different subpopulations of mDA neurons are
associated with distinct diseases. The selective degeneration of SN dopamine neurons causes the
movement impairments in Parkinson’s disease. The dysfunction of VTA neurons has been
associated with several neurological disorders including ADHD, anxiety, schizophrenia and autism
and often these disorders originate during embryonic development. The VTA neurons consist of
several subpopulations, but it is unclear which part of the VTA is deregulated in these diseases.
All mDA neurons are derived from a common pool of neural progenitor cells, but it has remained
unclear how distinct subpopulations of mDA neurons are specified during early developmental
stages. We have recently identified a transcription factor code that subdivides the mDA progenitor
domain in a lateral and medial domain. Expression analysis has shown that the medial neural
progenitor cells gives rise to SN neurons, while VTA neurons are derived from the lateral progenitor
cells. The transcription factor Nolz1 is selectively expressed in these lateral progenitor population
and later during development in a subset of VTA dopamine neurons. However, the function of
Nolz1 in controlling the differentiation of VTA neurons has not been investigated. Also, the function
of Nolz1 expressing VTA neurons is unclear. We recently received ES cell lines with targeted
mutations in Nolz1. We will generate mouse lines that will allow is to study “early” and “late” roles
of Nolz1 in VTA neurons. In addition, we will use embryonic stem (ES) cell derived mDA neurons to
analyse genome wide gene expression changes upon ablation of Nolz1 function. Recently, we have
shown that overexpression of lineage specific transcription factors in ES cell results in the
generation of homogeneous cultures of desired neuronal population, which can be used to model
diseases in vitro. VTA neurons are associated with several neurodevelopmental disorders that can
have both a genetic or environmental cause. To be able to model these diseases in vitro we will use
Nolz1 to direct the differention of ES cells towards VTA dopamine neurons. This will allow us to get
novel mechanistic insights into neurodevelopmental disorders.
Training Objectives:
This is a multidisciplinary project and will make use of different model systems. The student will
gain experience in working with embryonic stem cells and mice and use a number of techniques
including fluorescence imaging, electrophysiology and RNA sequencing to reveal the role of Nolz1
in the specification and maintenance of VTA neurons. Furthermore, the student will use ES
differentiation protocols to model diseases that are associated with VTA neurons in vitro.
The University of Leicester runs a variety of training modules and courses that the student will be
encouraged to attend. In the unit, the student will follow weekly external and internal seminar
programs and will be encouraged to attend the postdoc/student forums which run each month.