Dr Anton Nikolaev
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Lecturer in Neuroscience Room: D232 Alfred Denny building |
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| General |
Brief career history
Research interestsOur research is focused on investigating the neuronal circuits responsible for information processing in the visual system. The vertebrate visual system is able to recognize a remarkable number of objects of different appearances but the mechanisms and neural circuits underlying this ability are not known. To tackle this problem we use in vivo imaging of neuronal activity in zebrafish and follow the processing of visual information in different brain areas. Professional activities
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| Research |
Neuronal circuits involved in processing of visial information in zebrafish1. To understand the organisation of neuronal circuits performing processing of visual information in zebrafish. Using a combination of behavioural and imaging techniques we study how the zebrafish visual system processes visual information. Our main goal is to understand how information about object identity is encoded in the activity of visual neurons. The range of questions we ask includes: what features are extracted by the early visual system in order to make object recognition efficient? How do these features converge to form receptive fields of object recognising neurons? What is the role of adaptation in this process? To answer these questions we image neuronal activity in zebrafish larvae. We are using zebrafish lines expressing calcium activity indicators in all or subset of visual neurons. These indicators change their brightness when neuron is active. The advantage of this method is that it is non-invasive and allows for the simultaneous study of a large population of neurons - something that is currently unfeasible using other techniques. 2. To understand how memory is encoded in changes in synaptic strength. We are develop GFP based reporters of long-term potentiation and long-term depression. These reporters will be used in vivo to understand how simple forms of associative and non-associative memory are implemented in changes in synaptic strength. To answer these questions we are developing behavioural paradigms that will allow us to combine evaluation of memory formation with in vivo imaging of synaptic strength.
Collaborators: |
| Teaching |
Teaching experience: 2015: Postgraduate Certificate in Learning and Teaching from the University of Sheffield (Fellow of The Higher Education Academy, FHEA) Undergraduate and postgraduate taught modules Level 2:
Level 3:
Masters (MSc):
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| Opportunities |
PhD Opportunities1. The Role of cilia in processing of visual information Supervisors: Neurons of the vertebrate central nervous system, including these in the hippocampus and the cerebral cortex, are ciliated. The function of these neuronal cilia remains, however, a mystery. It is currently believed that central nervous system cilia may contribute to higher brain functions, such as memory and their malfunction may lead to psychiatric disorders, including schizophrenia and autism. The proposed project will investigate the role of cilia in the processing of visual information in the retina using the zebrafish model. A combination of state-of-the-art techniques, including molecular genetics and 2-photon imaging of neuronal activity, will be used to study how the activity of visual neurons is affected by mutation causing abnormal ciliogenesis. Keywords: Molecular Biology, Neuroscience/Neurology For informal enquiries about this project, please contact:
2. Understanding how memory is recorded in the brain Supervisor: Understanding how memory is stored in the brain is one of the ultimate goals of neuroscience. The cellular basis of memory formation is a change in the synaptic strength during two processes: long term potentiation (LTP) and depression (LTD). Molecular details of both LTP and LTD are well understood (reviewed in Citry and Malenka, 2008) but exactly how changes in synaptic strength lead to memory formation is unclear. For example, it is unknown whether memory is stored in a large population of synapses or in changes of individual synapses. It is also unclear how many bits (or perhaps bytes or even kilobytes?) of information is stored in an individual synapse and how synaptic plasticity is affected during multiple neurological disorders. To investigate these kinds of problems requires in vivo imaging using optical reporters of synaptic plasticity in individual synapses. One such reporter, AMPAR-pHluorin, reports trafficking of AMPA receptors during long-term potentiation. It has been used to study molecular details of LTP and LTD in cultured neurons (Ashby et al., 2004), while understanding how LTP and LTD encode memory needs to be performed on behaving animals. The proposed project aims at using of AMPAR-pHluorin in vivo to understand how visual memory is stored in the zebrafish brain. The zebrafish brain is relatively simple, yet able to memorise a large number of different shapes. The project will utilise state-of-the-art imaging and molecular biology methods to answer the questions outlined above. Keywords: Neuroscience/Neurology For informal enquiries about this project, please contact: Further information about these projects, and how to apply, can be found on our PhD Opportunities page: |
Selected publications
Journal articles
- Baden T, Nikolaev A, Esposti F, Dreosti E, Odermatt B & Lagnado L (2014) A Synaptic Mechanism for Temporal Filtering of Visual Signals. PLoS Biology, 12(10). View this article in WRRO
- Nikolaev A, Leung KM, Odermatt B & Lagnado L (2013) Synaptic mechanisms of adaptation and sensitization in the retina. Nature Neuroscience, 16(7), 934-941.
- Zheng L, Nikolaev A, Wardill T, O'Kane C, de Polavieja GG & Juusola M (2009) Network Adaptation Improves Temporal Representation of Naturalistic Stimuli in Drosophila Eye: I Dynamics. PLoS One, 4(1). View this article in WRRO
- Odermatt B, Nikolaev A & Lagnado L () Encoding of Luminance and Contrast by Linear and Nonlinear Synapses in the Retina. Neuron, 73(4), 758-773.