Methods in the lab:
- Large scale extracellular recordings of populations of neurons.
- Two photon laser scanning microscopy of neuronal structure and function.
- Behavioural training.
- Immunohistochemistry.
- Genetic tools for cell type specific targeting.
The project:
The visual cortex has been the canonical model for studying cortical processing and plasticity. The visual cortex is placed on top of the rodent brain and is thus easy accesible for imaging techniques. The anatomic organization of this brain area is well understood and easy control of the sensory inputs to the neural processing in this area make visual cortex a suitable candidate for mechanistic studies of cortical processing and plasticity.
In order to study brain plasticity it is necessary to measure the changes in neuron responses to e.g. a sensory stimulus. A number of functional brain mapping techniques have been developed in recent years. One of these techniques is optical imaging of intrinsic signals (OIS). Optical imaging of intrinsic signals maps the brain by measuring intrinsic activity-related changes in tissue reflectance. Functional physiological changes, such as increases in blood volume, hemoglobin oxymetry changes, and light scattering changes, result in intrinsic tissue reflectance changes that are exploited to map functional brain activity. Although activity-related intrinsic changes in tissue reflectance associated with electrical activity or metabolism were first observed over 50 years, it was not until the 1980s that these intrinsic optical changes were used to map cortical activity in vivo. The increasing popularity of optical imaging is largely because this technique offers both high spatial and high temporal resolution simultaneously.
In the proposed master project we ask how removing a potential break to plasticity influence the topographic map organization and plasticity in visual cortex in the adult brain.
To address this, the candidate will establish the technique of optical intrinsic signal imaging in the lab and use this to record cortical responses to visual stimulation after manipulations. We will remove one potential break to plasticity in the adult brain; namely perineuronal nets, which are specialized extracellular matrix structures surrounding the neurons. Thereafter, brain plasticity will be induced and the effects on the visual cortical response maps will be measured using the OIS. From there we may move on to investigate transgenic mouse lines to reveal molecular mechanisms to brain plasticity.
The student must have interest in technology development. The candidate will work with rodents and in close collaboration with other members of the research group. The methods are technically demanding and the master student need to be highly motivated and have a strong interest in neuroscience.
The Hafting-Fyhn lab is a research group under the Program for Physiology and Neurobiology. The group currently consists of Marianne Fyhn (PI), Torkel Hafting (PI), two post docs, one PhD student and one master student. We can accept one student in this project.
Relevant reading: Kalatsky and Stryker, 2003; Hofer et at., 2009.