Laboratory of Neural Circuits and Behaviour
Research Interests
Olfactory decisions: One of our scientific goals is to help unravel the behavioural relevance of genetically identified subsets of neurons in the olfactory pathway. We are aiming to identify the circuit motifs that give rise to olfactory specific behaviours by controlling the neural activity in a cell-type specific manner. In the olfactory bulb, granule cells and periglomerular cells control the synaptic inhibition, however their functional relevance is largely unknown. Addressing these questions is fundamentally important as the answers will provide a neuromechanistic insight on the olfactory information processing and will further allow creation of novel animal models for brain disorders associated with excitatory/inhibitory imbalance.
Multisensory decisions: The second, and a complimentary, focus of the lab is the neural mechanisms of multisensory decision-making, with a particular interest in understanding the mechanisms how animals combine sensory information across modalities. As most of our decision-making involves the processing of multimodal sensory signals, combining the information coming from the sensory periphery will help us to understand how synergy and redundancy in sensory information across sensory modalities can help to encode the sensory stimulus and create stimulus percept. In naturalistic environments, rodents heavily rely on olfactory and tactile sensing while synchronizing sniffing and whisking to optimize their sensory navigation. Using recently developed automated behavioural assays (Abraham et al., 2010; 2012; Celikel & Sakmann 2007; Voigts et al, 2015), high-resolution tracking systems and targeted optogenetic control of neural activity we mechanistically study the neural basis of multi-modal sensory decision-making. This work is a collaborative initiative between IISER Pune and Radboud University/Donders Institute in the Netherlands (http://www.ru.nl/donders/).
Neurogenesis and synaptic inhibition: The brain works efficiently on a balance between the excitatory and inhibitory synaptic transmission happening on millisecond time scales. The rodent olfactory bulb (OB), the first relay station in olfactory pathway, offers an excellent model to study the excitatory-inhibitory balance. Synaptic inhibition exhibited by the interneurons of OB is controlling the output from OB. These interneurons are produced from neural stem cells found in the subventricular zone located in the lateral ventricles walls. Before integrating into the existing neural network as functional interneurons, the neuroblasts migrate tangentially along the rostral migratory stream towards the OB and inside the OB they move radially to their final destinations. As the inhibitory interneurons are generated continuously throughout the lifespan, what are the factors controlling the synaptic integration of adult-born inhibitory interneurons? We are aiming to address this question by using a combination of imaging and behavioural approaches.
Funding
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Wellcome Trust DBT India Alliance Senior Fellowship (2023 - 2028)
Wellcome Trust DBT India Alliance Intermediate Fellowship (2015 - 2021)
DST Cognitive Science Research Initiative (2018 - 2022)
BIRAC Academic Innovation Research Grant (2019-2020)
IISER, Pune
Radboud Excellence Initiative
Figure: A. Modification of GCs in the OB by direct stereotaxic delivery of viral vectors into the GC layer. Red square shows the Cre recombinase expressing GCs in the OB in comparison to the whole brain (DAB-stained transverse section). Scale bar 2.5 mm. Right upper corner: confocal image of a single GC (Cre expressing, labeled with mGFP). Scale bar 25 μm; Abraham et al 2010. B. Mouse involved in an olfactory behavioral assay. C. Example traces olfactory responses towards a rewarded odor in a discrimination assay.
