Developig a mouse model of visual heminegelct by means of cortex-wide, spot-wise, optogenetics

Background research project

Visual hemineglect, or unilateral spatial neglect, is characterized by the inability to respond or orient towards stimuli presented in the visual hemispace contralateral to a unilateral lesion, most commonly the posterior parietal area. Instead, patients direct their attention towards the ipsilateral side of space. Despite treatment and behavioural recovery, even though patients perform well on simple paper-and-pencil tasks, they may nevertheless show lateralized impairments (e.g., extinction) on more demanding time-constrained tasks or real-life situations.

Neglect and extinction cannot be explained by primary sensory deficits and are often seen the result of an interhemispheric disbalance in the attentional system. However, more recently, evidence indicates extinction may also be due to deficits in the decision-making circuitry. To investigate the neural mechanisms underlying spatial neglect this project aims to develop a mouse model, allowing for high spatial and temporal resolution causal manipulations.

The first aim of this project is to find a mouse homologue of visual hemineglect, i.e., a lesion or temporal inhibition leads to similar behavioural symptoms as the human and non-human primate condition. Next year, this will be done by means of laser-scanning optogenetics, which allows for rapid cortex-wide inhibition within animals. Once a target region is found, the neural mechanisms of neglect will be described by means of electrophysiological recordings using laminar silicone probes.

Student’s role in the project

In the coming months we plan to start behavioural training on a visual detection task and conduct optogenetic and electrophysiological pilot experiments. We are looking for a highly motivated and ambitious master’s student who will: 1) be in charge of daily behavioural training, 2) assist in optogenetic experiments, 3) assist in surgeries (headbar implantation, clear-skull cap), 4) perform histology to examine opsin expression post-mortem using fluorescent microscopy, 5) analyse behavioural data in MATLAB and/or Python. Additionally, the student may assist in electrophysiological recordings and the analysis, and potentially aid in the development of a stroke surgery later in the project.

Duration: 5-9 months

Start date: February – April 2022

Supervisor: Medina Husić (PhD candidate)

Institute: Swammerdam Institute for Life Sciences, University of Amsterdam

Lab: Cognitive and Systems Neuroscience

If you would like to apply please send your CV and a short motivation to Medina Husić ([staat bij de werkgever]). Feel free to reach out if you have any questions!