Humboldt-Universität zu Berlin - LARKUM LAB

Dr. Mazahir T. Hasan



Cortical circuits in learning and memory

‘Where’ and ‘how’ memories are encoded in a nervous system is one of the most challenging and also the most fascinating endeavor in biological research. My research interest is to investigate the hippocampal-cortical and corticocortical circuits and the underlying cellular and molecular mechanisms of learning and memory formation, storage, and retrieval. As a first step towards this direction, I aim to identify and validate a ‘minimal’ memory circuit (MMC) using the ‘trace’ eyeblink conditioning as a simple model of declarative memory.

To achieve my goals, I have developed virus-delivered genetic approaches to (1) Reveal the neural substrates of learning and memory in the cortex by chronic in vivo two-photon Ca2+ imaging, (2) Identify and permanently tag experience-activated neurons, which possibly represent a ‘minimal’ memory circuit (MMC), and express in the tagged neurons any gene-of-interest including the photoactivatable microbial proteins for activity manipulation to control memory and behavior, (3) Block synaptic plasticity in any


cell type and brain region(s) before and after memory formation, by inducibly deleting the Grin1 gene and removing the NMDA receptor, a glutamate receptor that acts as a coincident detector for membrane depolarization and synaptic transmission, (4) Inducibly and reversibly silence synaptic transmission in any cell type and brain region(s), and (5) Anatomically and functionally map the input/output connectivity of an MMC at cellular and possibly synaptic level. Clearly, a better understanding of learning and memory processes is bound to facilitate the development of novel therapeutic approaches to treat (or even cure) various memory-related brain dysfunctions, such as mental dementia, amnesia and the Alzheimer’s disease.


For more information about my work, please visit my research website:




‘The Science Bridge’ initiative

In addition, I have also launched ‘The Science Bridge’ (TSB) initiative, which employs ‘science in diplomacy’ to improve relations between Western and Middle-Eastern countries. For more information please visit our website:


I am a full member of the European Dana Alliance for the Brain (EDAB). Download interview published in EDAB Newsletter-Winter-2013.


Click this link for my recent interview on "Brain uses cortex for making sensory associations, not the hippocampus" in Deutschlandfunk.