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Séminaire - Prateep BeedCellular-Network interactions in the Entorhinal Cortex in physiology and pathophysiology

Abstract :

The entorhinal cortices (medial and lateral subdivisions) in the temporal lobe of the brain are key structures relaying memory related information between the neocortex and the hippocampus. The medial entorhinal cortex (MEC) routes spatial information whereas the lateral entorhinal cortex (LEC) routes predominantly olfactory information to the hippocampus. Recent studies have shown that unlike previously conceived, both the MEC and LEC performs several independent neuronal computations for spatial learning and memory.
Besides, in many neurodegenerative diseases the entorhinal cortices are severely affected with extensive neuronal loss. However, since little is known about the intrinsic microcircuitry of the neurons it has been challenging thus far to find cellular correlates of the network functions. We have undertaken several strategies to broaden our understanding of the microcircuitry of the EC in function and dysfunction. We investigated the organization of the inhibitory microcircuitry onto principal neurons in the superficial layers.
The inhibitory network predominantly synchronizes the network to oscillate in the gamma frequency range. We found a gradient in such network activity along the dorso-ventral axis which might have important implications for hippocampal information processing as different inputs are routed along this axis from the cortex to the hippocampus.


 We went a step further to dissect the fine-scale connectivity of the entorhinal circuitry using a multiple-patch approach. In the last part, I will discuss the early cortical alterations in microcircuitry in a mouse model for Alzheimer’s disease. Knowing how circuits function in physiology, we can now go a step further to understand cellular-network alterations that occur in the early stages of pathophysiology

Selected publications

• Beed P, Gundlfinger A, Schneiderbauer S, Song J, Böhm C, Burgalossi A, Brecht M, Vida I & Schmitz D. (2013). Inhibitory gradient along the dorso-ventral axis in the medial entorhinal cortex. Neuron 79:1197-1207.

• Canto CB, Koganezawa N, Beed P, Moser EI & Witter MP. (2012). All Layers of Medial Entorhinal Cortex Receive Pre- and Parasubicular Inputs. J. of Neuroscience 32:17620-17631.

• Maier N, Tejero-Cantero A, Dorrn AL, Winterer J, Beed P, Morris G, Kempter R, Poulet JF, Leibold C* & Schmitz D*. (2011). Coherent phasic excitation during hippocampal ripples. Neuron 72:137-152.

• Beed P, Bendels M, Wiegand HF, Leibold C, Johenning FW* & Schmitz D*. (2010). Analysis of excitatory microcircuitry in the medial entorhinal cortex reveals cell-type-specific differences. Neuron 68:1059-1066.

• Johenning FW, Beed P, Trimbuch T, Bendels M, Winterer J & Schmitz D. (2009). Dendritic compartment and neuronal output mode determine pathway-specific long-term potentiation in the piriform cortex. J. of Neuroscience 29:13649-13661.

• Trimbuch T, Beed P, Vogt J, Schuchmann S, Maier N, et al. (2009). Synaptic PRG-1 modulates excitatory transmission via lipid phosphate-mediated signaling. Cell 138:1222-1235.

Scientific focus :

 

bio

After a bachelor’s degree in Industrial Engineering and a master’s degree in Cognitive Psychology & Neurosciences, I went on to complete my PhD in 2010 in Neuroscience thematically focusing on spatial navigation & decision-making. In 2011, I received the Tiburtius-Award for young investigators doing exceptional research.

Given the interdisciplinary academic background, I started seeing the strength in combining the seemingly independent disciplines of study thereby shaping a new kind of thought process – design thinking. In 2012, this gave way to the co-founding of Biomimicry Germany, a non-profit organization fostering sustainable innovations inspired by nature’s smart design strategies.

After spending several years in academia both in India and Germany, I would like to stress on the importance of interdisciplinary research and problem solving. I seek to inspire young scientists and investigators about the same. The best innovative strategies grounded in well-researched science with negligible-to-zero environmental impact should shape the future. With strategic partners in industry, research, design, and architecture we can merge interdisciplinary innovations with cross-sector implementation especially in developed and developing countries from the ‘resource-rich’ to the ‘resource-limited’.