Felix Taschbach profile
Felix
Taschbach

Biography

I am currently a PhD candidate in the Biological Sciences Program at UCSD, where I am fortunate to work with Prof. Marcus Benna. I received my MSc in Systems Biology at Maastricht University. I completed my master thesis on computational neuroscience working in the lab of Stefano Fusi at Columbia University.

My research is on how populations of neurons encode information within ethological contexts. Specifically, I am interested in how changes within an animal's internal state lead to changes within its neural representations and how these representations evolve over time. For instance, how chronic mild stress can induce depression.

News

  • [May. 2025] Mario Aguilera was kind to write a short write-up about the recent paper for UCSD Today
  • [May. 2025] Paper in collaboration with the phenomenal Assaf Ramot has published in Nature.
  • [Jul. 2024] Published review on mixed selectivity in Neuron with Stefano Fusi.
  • [Mar. 2024] Paper with Reesha Patel uploaded to bioRxiv.
  • [Jul. 2023] I advanced to PhD candidacy.
  • [Oct. 2022] Paper with Fergil Mills uploaded to bioRxiv.

Teaching

  • Graduate Instruction Assistant, Python for Biologists at University of California San Diego, Winter 2023
  • Teaching Assistant, Computational Neuroscience at Neuromatch Academy, Summer 2022
  • Graduate Instruction Assistant, Bioinformatics Laboratory at University of California San Diego, Spring 2022
  • Graduate Instruction Assistant, Computational Models of the Brain at University of California San Diego, Spring 2021
  • Teaching Assistant, Imperative Programming at Maastricht University, Spring 2017
  • Teaching Assistant, Introduction to Programming at Maastricht University, Fall 2016

Conferences

  • [CoSyNe 2025] Workshop on Individual Differences
  • [SfN 2024] Shared Representation Discovery
  • [FENS 2024] Shared Representation Discovery
  • [SfN 2022] Functional characterization of input-defined neurons within the primary motor cortex during motor learning.
  • [CCN 2019] Abstract representations of space in the mouse dentate gyrus.
Neural mixed selectivity diagram
Neuron
2024

Mixed selectivity: Cellular computations for complexity

The property of mixed selectivity has been discussed at a computational level and offers a strategy to maximize computational power by adding versatility to the functional role of each neuron. Here, we offer a biologically grounded implementational-level mechanistic explanation for mixed selectivity in neural circuits.

Motor learning refines thalamic influence on motor cortex

Assaf Ramot & Felix Taschbach et al.

The primary motor cortex (M1) is central for the learning and execution of dexterous motor skills1-3, and its superficial layer (layers 2 and 3; hereafter, L2/3) is a key locus of learning-related plasticity1,4-6. It remains unknown how motor learning shapes the way in which upstream regions activate M1 circuits to execute learned movements. Here, using longitudinal axonal imaging of the main inputs to M1 L2/3 in mice, we show that the motor thalamus is the key input source that encodes learned movements in experts (animals trained for two weeks). We then use optogenetics to identify the subset of M1 L2/3 neurons that are strongly driven by thalamic inputs before and after learning. We find that the thalamic influence on M1 changes with learning, such that the motor thalamus preferentially activates the M1 neurons that encode learned movements in experts. Inactivation of the thalamic inputs to M1 in experts impairs learned movements. Our study shows that motor learning reshapes the thalamic influence on M1 to enable the reliable execution of learned movements.

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Nature

Amygdalostriatal transition zone neurons encode sustained valence to direct conditioned behaviors

Fergil Mills et al.

Here, we present the amygdalostriatal transition zone (ASt) as a missing piece of a highly conserved process of paramount importance for survival, which represents an internal state (e.g. fear) that can be expressed in multiple motor outputs (e.g. freezing or escape). From in vivo cellular resolution recordings that include both electrophysiology and calcium imaging, we find that ASt neurons are sparse coding, extremely high signal-to-noise, and maintain a sustained response for negative valence stimuli for the duration of the defensive behavior.

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Preprint

Social isolation recruits amygdala-cortical circuitry to escalate alcohol drinking

Reesha Patel et al.

How do social factors impact the brain and contribute to increased alcohol drinking? We found that social rank predicts alcohol drinking, where subordinates drink more than dominants. Furthermore, social isolation escalates alcohol drinking, particularly impacting subordinates who display a greater increase in alcohol drinking compared to dominants.

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Preprint

Cortical ensembles orchestrate social competition through hypothalamic outputs

Padilla-Coreano & Batra et al.

Most social species self-organize into dominance hierarchies, which decreases aggression and conserves energy, but it is not clear how individuals know their social rank. We have only begun to learn how the brain represents social rank, and guides behavior on the basis of this representation. The medial prefrontal cortex (mPFC) is involved in social dominance in rodents, and humans. Yet, precisely how the mPFC encodes relative social rank and which circuits mediate this computation is not known.

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Nature