Structure-function relationships in the hippocampus and parahippocampal region
Andrea Burgalossi, Christian Ebbesen, Robert Naumann, Saikat Ray, Nacho Sanguinetti, Helena Schmidt, Qiusong Tang and Michael Brecht
The hippocampus and the parahippocampal regions play an integral aspect in how we store and retrieve memories. We investigate the microcircuits underlying these mysterious processes, by investigating how spatial memories are represented in the hippocampus, medial entorhinal cortex, subiculum, parasubiculum and presubiculum. By employing tetrode, juxtacellular and patch clamp recordings in freely moving animals we identify functionally distinct cells like place cells, grid cells, border cells and head direction cells. We further determine the anatomical phenotypes of these cells by a combination of the genetic markers they express and their morphology to determine structure function relationships in these spatial memory circuits. Though a majority of our experiments are performed in adult rats, we also explore how these circuits are formed about and how they are generalized across evolution by investigating them anatomically across ontogeny and phylogeny.
- Grid-layout of medial entorhinal pyramidal neurons across species. (Ray et al., Science, 2014; Naumann et al., Journal of Comparative Neurology, 2015)
- Identified calbindin-negative stellate border cell in the medial entorhinal cortex demonstrating the structural, spatial and temporal properties of the neuron. (Tang et al., 2014)
A Grid in the Brain
https://www.youtube.com/watch?v=6gBi9DwXL9M
Relevant publications
Schmidt H, Gour A, Straehle J, Boergens KM, Brecht M, Helmstaedter M (2017) Axonal synapse sorting in medial entorhinal cortex. Nature, 549(7673), 469.
Ray S, Burgalossi A, Brecht M, Naumann RK (2017) Complementary Modular Microcircuits of the Rat Medial Entorhinal Cortex. Frontiers in Systems Neuroscience, 11.
Ebbesen CL, Reifenstein ET, Tang Q, Burgalossi A, Ray S, Schreiber S, Kempter R, Brecht M (2016) Cell Type-Specific Differences in Spike Timing and Spike Shape in the Rat Parasubiculum and Superficial Medial Entorhinal Cortex. Cell Rep. 16(4):1005-15.
Ray S, Brecht M (2016) Structural development and dorsoventral maturation of the medial entorhinal cortex. Elife. 5. pii: e13343.
Tang Q, Burgalossi A, Ebbesen CL, Sanguinetti-Scheck JI, Schmidt H, Tukker JJ, Naumann R, Ray S, Preston-Ferrer P, Schmitz D, Brecht M (2016) Functional Architecture of the Rat Parasubiculum. J. Neurosci. 36(7):2289–2301.
Reifenstein ET, Ebbesen CL, Tang Q, Brecht M, Schreiber S, Kempter R (2016) Cell-Type Specific Phase Precession in Layer II of the Medial Entorhinal Cortex. J. Neurosci. 36(7):2283–2288.
Tukker JJ, Tang Q, Burgalossi A, Brecht M (2015) Head-Directional Tuning and Theta Modulation of Anatomically Identified Neurons in the Presubiculum. J. Neurosci. 35(46):15391–15395.
Tang Q, Ebbesen CL, Sanguinetti-Scheck JI, Preston-Ferrer P, Gundlfinger A, Winterer J, Beed P, Ray S, Naumann R, Schmitz D, Brecht M, Burgalossi A (2015) Anatomical Organization and Spatiotemporal Firing Patterns of Layer 3 Neurons in the Rat Medial Entorhinal Cortex. J Neurosci. 35(36):12346-54.
Naumann RK, Ray S, Prokop S, Las L, Heppner FL, Brecht M (2015) Conserved size & periodicity of pyramidal patches in layer 2 of medial/caudal entorhinal cortex. J Comp Neurol. 524(4):783-806.
Tang Q, Brecht M, Burgalossi A (2014) Juxtacellular recording and morphological identification of single neurons in freely moving rats. Nat Protoc 9:2369–2381.
Tang Q, Burgalossi A, Ebbesen CL, Ray S, Naumann R, Schmidt H, Spicher D, Brecht M (2014) Pyramidal and Stellate Cell-specificity of Grid and Border Representations in Layer 2 of Medial Entorhinal Cortex. Neuron 84(6):1191-7.
Burgalossi A, von Heimendahl M, Brecht M (2014) Deep layer neurons in the rat medial entorhinal cortex fire sparsely irrespective of spatial novelty. Front. Neural Circuits 8:74.
Ray S, Naumann R, Burgalossi A, Tang Q, Schmidt H, Brecht M (2014): Grid-layout and Theta-modulation of Layer 2 Pyramidal Neurons in Medial Entorhinal Cortex. Science 343(6173):891-6.
Burgalossi A, Brecht M (2014) Cellular, columnar and modular organization of spatial representations in medial entorhinal cortex. Curr Opin Neurobil 24:47–54.
Brecht M, Ray S, Burgalossi A, Tang Q, Schmidt H, Naumann R (2013) An isomorphic mapping hypothesis of the grid representation. SoPhil. Trans. R.c. 369(1635):20120521.
Herfst L, Burgalossi A, Haskic K, Tukker JJ, Schmidt M, Brecht M (2012) Friction-based stabilization of juxtacellular recordings in freely moving rats. J Neurophysiol 108(1): 697–707.
Burgalossi A, Herfst L, von Heimendahl M, Förste H, Haskic K, Schmidt M, Brecht M (2011) Microcircuits of Functionally Identified Neurons in the Rat Medial Entorhinal Cortex. Neuron 70: 773-786.