Rajeevan Narayanan Therpurakal
Marie Skłodowska-Curie Fellow
Rajeevan Narayanan, Therpurakal joined the Department of Physiology, Anatomy and Genetics (DPAG) as a Marie-Curie Fellow in 2020 November. He is excited about the challenges to dissect neuronal circuits that underly fear behaviour and expression since these topics have impact on how we think about neurological and psychiatric conditions such as post-traumatic stress disorder (PTSD).
Rajeevan Narayanan, Therpurakal has completed his PhD in neuroscience at the University of Muenster with Prof Hans-Christian Pape in a project investigating the basic network mechanisms of fear learning and extinction. Combining fear conditioning paradigm in conjunction with chronic implantation of multiple electrodes and acquiring data on freely behaving mice, he demonstrated amygdala-hippocampal interaction reflects a dynamic interaction of ensemble activities related to various stages of fear memory consolidation and/or retention, and support the notion that recent and remote memories are organized through different network principles (Narayanan et al., Eur J Neurosci 25 (2007) 1823-31; Narayanan RT et al., Neuroreport 18 (2007) 1107-11; Lesting J*, Narayanan RT*, PLoSOne. (2011) 6(6):e21714). After the PhD, Rajeevan joined in a project called ‘Cortical column in silico’ led by Prof. Bert Sakmann and Christiaan De Kock in collaboration with Marcel Oberlaender at Vrije University Amsterdam, The Netherlands to obtain single neuron morphologies of vibrissal somatosensory cortex neurons (vS1) (Egger R, Narayanan RT et al., PLoS Comput Biol. (2012) Dec;8(12); Narayanan RT et al., J Vis Exp. (2014) Feb 25;(84). After three years of post-doctoral work at the CNCR, Vrije University, he continued to investigate cell-type-specific structural and functional principles of rat vibrissal somatosensory and vibrissal motor cortex at in Max Planck Tuebingen, Germany and at Research Center Caesar, Bonn, Germany with Marcel Oberlaender (Narayanan RT et al., Cereb Cortex. (2015) Apr 1; Narayanan RT et al., Frontiers in Neuroanatomy (2017); Egger R*, Narayanan RT*, Neuron, (2020) Jan 8;105(1):122-137.
As a Marie-Curie Fellow, he will work with Zoltán Molnár's and Ed Mann’s groups to investigate the presynaptic and post-synaptic connections of L6B neurons of the infralimbic medial prefrontal cortex upon fear memories and traumatic events. In particular, he will investigate the electrophysiological properties and anatomical connectivity of L6 neurons (L6b) of the medial prefrontal cortex (mPFC) using state-of-the-art techniques and tools such as modified rabies virus labelling, DREADD technology and optogenetics in a transgenic mouse line that selectively expresses Cre-recombinase in a subpopulation of layer 6b neurons. Exploring mPFC neural circuits may not only provide more in-depth insight into its involvement in cognitive behaviours but also in a variety of psychiatric conditions such as post-traumatic stress disorders (PTSD). The outcome of this study will establish the functional role of L6b of the mouse medial prefrontal cortex to its specific involvement in eliciting specific behavioural outcomes.
Cortical Output Is Gated by Horizontally Projecting Neurons in the Deep Layers
Egger R. et al, (2020), Neuron, 105, 122 - 137.e8
Morphological characterization of HVC projection neurons in the zebra finch (Taeniopygia guttata
Benezra SE. et al, (2018), Journal of Comparative Neurology, 526, 1673 - 1689
Cell Type-Specific Structural Organization of the Six Layers in Rat Barrel Cortex
Narayanan RT. et al, (2017), Frontiers in Neuroanatomy, 11
EM connectomics reveals axonal target variation in a sequence-generating network
Kornfeld J. et al, (2017), eLife, 6
Dendritic and Axonal Architecture of Individual Pyramidal Neurons across Layers of Adult Human Neocortex
Mohan H. et al, (2015), Cerebral Cortex, 25, 4839 - 4853