Dr Karolina Farrell

The research group “Sensory Dynamics and Behaviour” of Prof. Dr. Tobias Ackels at the Institute of Experimental Epilepsy and Cognition Research at the University Hospital Bonn invites applications for a position as: Postdoctoral Researcher (m/f/d) The position is initially limited to three years (TV-L E13/100%), starting from April 2026 or as soon as possible.

Postdoc position in systems neuroscience!
Excited to recruit a postdoc for my lab at the University of Bonn.
🔬 In vivo physiology (Neuropixels, 2P/miniscope)
🐭 Head-fixed & freely moving behaviour
💡 Optogenetics/chemogenetics
⏳ Start: ASAP | Application deadline: 28.02.2026
More info below ⬇️

AI is not a peer, so it can’t do peer review If we still believe that science is a vocation grounded in argument, curiosity and care, we can’t delegate judgement to machines, says Akhil Bhardwaj

'to treat peer review as a throughput problem is to misunderstand what is at stake. Review is not simply a production stage in the research pipeline; it is one of the few remaining spaces where the scientific community talks to itself.' 1/3

RA job alert. We are looking for a fearless experimentalist to join our experiments on cortical neuromodulators during visually guided learning, lead by @michael-lynn.bsky.social . Opportunity to learn 2p imaging, design and conduct experiments. RT plz. Apply here: my.corehr.com/pls/uoxrecru...

Electrophysiological Correlates of Reinforcement Learning in the Human Ventral Tegmental Area https://www.biorxiv.org/content/10.64898/2026.01.27.701696v1

Predictive coding of reward in the hippocampus - Nature Calcium imaging of mouse hippocampal neurons while mice learn a reward-based task over several weeks provides insight into the evolution of the hippocampal reward representation during extended periods of experience.

Nature research paper: Predictive coding of reward in the hippocampus

go.nature.com/49mB13V

Dorsal striatal dopamine integrates sensory and reward prediction errors to guide perceptual decisions Perceptual decisions are shaped by expectations about sensory stimuli and rewards, learned through sensory and reward prediction errors. Dopamine is known to convey reward prediction errors that shape...

New preprint. We show that in addition to reward prediction errors (RPEs), dorsal striatal dopamine signals encode sensory prediction errors (SPEs), the difference between sensory prior & observed stimulus. www.biorxiv.org/content/10.6...

Positive reward prediction errors during decision-making strengthen memory encoding - Nature Human Behaviour Jang and colleagues show that positive reward prediction errors elicited during incidental encoding enhance the formation of episodic memories.

1/3 How reward prediction errors shape memory: when people gamble and cues signal unexpectedly high reward probability, those incidental images are remembered better than ones on safe trials, linking RL computations to episodic encoding. #RewardSignals #neuroskyence www.nature.com/articles/s41...

Meet the Group Breaking People Out of AI Delusions In this Discord server, people impacted by AI delusions and psychosis share their experiences — and even help users out of delusional spells.

NEW: A Discord community with nearly 200 members serves as a support group for people whose minds and lives have been upended by episodes of AI delusion and psychosis.

In some cases, members say, the group has helped people climb out of their destructive AI "spirals."

futurism.com/artificial-i...

Estrogen modulates reward prediction errors and reinforcement learning - Nature Neuroscience Dopamine encoding of reward prediction errors naturally fluctuates over females’ reproductive cycles with estrogenic signaling due to reduced expression of dopamine reuptake proteins.

Thrilled to share our new paper, out now in @natneuro.nature.com, uncovering how estradiol, the most potent estrogen, modulates reinforcement learning and reward prediction errors across biological levels. www.nature.com/articles/s41...

#blueprint 1/7

Subsecond dopamine fluctuations do not specify the vigor of ongoing actions Nature Neuroscience - Liu and colleagues show that the vigor (that is, speed and amplitude) of dexterous movements is not controlled by ongoing fluctuations in extracellular dopamine within the...

Delighted to see this finally out: rdcu.be/eO9oW
We tested whether brief striatal dopamine release events influence the vigor of skilled movements. Despite popular belief, we did not find any evidence linking rapid dopamine dynamics to motor vigor on a moment-by-moment basis.

Functional specialisation of multisensory temporal integration in the mouse superior colliculus - Nature Communications Whether and how anatomically distinct regions of the superior colliculus (SC) exhibit specialisation in multisensory temporal integration to facilitate different behavioural responses are not fully un...

Proud to have contributed to @gaiabianchini.bsky.social and @flor-iacaruso.bsky.social new paper on how the superior colliculus temporally integrates multisensory information

Hippocampus supports multi-task reinforcement learning under partial observability - Nature Communications Neural mechanisms underlying reinforcement learning in naturalistic environments are not fully understood. Here authors show that reinforcement learning (RL) agents with hippocampal-like recurrence, u...

How does the brain find its way in realistic environments? 🧠 Using deep RL and neural data, we show that hippocampal-like networks support navigation, learning, and generalisation in partially observable environments—mirroring real animal behaviour. Now out:
www.nature.com/articles/s41...
#neuroAI

Serial Ketamine Infusions for Depression This randomized clinical trial evaluates outcomes following adjunctive ketamine infusions vs midazolam for depression.

Serial Ketamine Infusions as Adjunctive Therapy to Inpatient Care for Depression
jamanetwork.com/journals/jam...

The effects of antidepressants on cardiometabolic and other physiological parameters: a systematic review and network meta-analysis We found strong evidence that antidepressants differ markedly in their physiological effects, particularly for cardiometabolic parameters. Treatment guidelines should be updated to reflect differences...

Open access link to new study in The Lancet:

The effects of antidepressants on cardiometabolic & other physiological parameters: a systematic review & network meta-analysis.

🧪🧠💊 #medsky
www.thelancet.com/journals/lan...

Out today at Neuron, our experiments show that frontal cortical representation of economic variables is jointly determined by spatial organization and downstream
connectivity of neurons, revealing a structured, multi-scale code for economic variables. www.cell.com/neuron/fullt...

A framework for advancing mechanistic neuro-behavioral biomarkers in psychiatry Neuropsychiatry has yet to surmount the fundamental challenge of mapping behavioral pathology to its underlying neural pathology. This gap limits the development of treatments for specific circuit pat...

In this review, @kangjoolee.bsky.social and colleagues propose a provisional formalism, considering mechanism type, severity, and time, to map neuropsychiatric behavioral pathology to its underlying dynamic neural mechanisms to advance the development of precision treatments.

Desensitization of opsin responses during all-optical interrogation depends on imaging parameters Significance The combination of two-photon calcium imaging and two-photon optogenetic stimulation, termed all-optical interrogation, provides spatial and temporal precision when recording and manipula...

All-optical experiments are great but @neurorussell.bsky.social found that opsin desensitization due to cross-talk between the imaging laser and the opsin causes major issues. These can be ameleorated with long inter-stimulus intervals & short imaging doses. All here: www.biorxiv.org/content/10.1...

Genetic therapies for neurological diseases Often, gene therapy reviews concentrate upon specific therapeutic modalities – particularly either viral vector-mediated or a non-viral approach. Here, we draw together a comprehensive array of knowle...

Sorry all, been a bit away from social media - but very happy to show our latest, slightly massive review on neuro gene therapy. Some quite amazing co-authors who dwarf me in their amazingness. Here, as a pre-proof. Still some (quite a bit) of finessing pharmrev.aspetjournals.org/article/S003... 🧪

UCL – University College London UCL is consistently ranked as one of the top ten universities in the world (QS World University Rankings 2010-2022) and is No.2 in the UK for research power (Research Excellence Framework 2021).

Post doc job alert 📢! Announcing a v exciting job on a Wellcome-funded project in my group at UCL, looking at auditory hallucinations... Advert here 👀: rb.gy/230w8l - deadline is end of Oct. Please apply! 1/5

UCL – University College London UCL is consistently ranked as one of the top ten universities in the world (QS World University Rankings 2010-2022) and is No.2 in the UK for research power (Research Excellence Framework 2021).

New #job alert! Clinical research fellow / postdoc in #computationalpsychiatry at the @mpc-comppsych.bsky.social / @uclqsion.bsky.social and UCL psychiatry. We will aim to understand the computations engaged by serotonin in the treatment of depression. Please re-sky. www.ucl.ac.uk/work-at-ucl/...

We have a PhD project here, along with many other cool projects:

"Characterising and predicting seizure onsets from longitudinal sEEG data",
www.crick.ac.uk/careers-and-...

with @flor-iacaruso.bsky.social (Crick), Torsten Baldeweg (UCL) and Martin Tisdall (UCL).

Apply by: 14 November 2025.

Corticonigral projections recruit substantia nigra pars lateralis dopaminergic neurons for auditory threat memories - Nature Communications The roles of distinct dopaminergic neuron subpopulations and the circuit projections driving their activity during threat behaviors remain incompletely understood. Here, the authors demonstrate that substantia nigra pars lateralis dopamine neurons receive selective, robust excitation from auditory and temporal association cortices, which, combined with rapid action potential firing, contributes to auditory threat conditioning.

Corticonigral projections recruit substantia nigra pars lateralis dopaminergic neurons for auditory threat memories
www.nature.com/articles/s41...

Phenomenal. In my 10 year update of A Brief History, I make the point that in the first edition, not one disease had been successfully treated using gene therapy. Today that number is at least 7.

Individual differences in decision-making shape how mesolimbic dopamine regulates choice confidence and change-of-mind - Nature Neuroscience Differences in neuroeconomic decision-making influence nucleus accumbens dopamine dynamics and reflect choice confidence during evaluation, as well as past and future value during re-evaluation, which...

Nature Neuroscience

Individual differences in decision-making shape how mesolimbic dopamine regulates choice confidence and change-of-mind

www.nature.com/articles/s41...

Prefrontal contribution to passive coping behaviour in chronic stress and treatment by fast-acting antidepressant - Neuropsychopharmacology Neuropsychopharmacology - Prefrontal contribution to passive coping behaviour in chronic stress and treatment by fast-acting antidepressant

Prefrontal contribution to passive coping behaviour in chronic stress and treatment by fast-acting antidepressant
www.nature.com/articles/s41...

Disruption of hippocampal-prefrontal neural dynamics and risky decision-making in a mouse model of Alzheimer’s disease Kim et al. show that 5XFAD mice exhibit persistent risk-taking and reduced behavioral flexibility in naturalistic “approach food-avoid predator” foraging paradigms. Simultaneous neural recordings reve...

This paper has everything:
- a predator avoidance task with an eagle puppet 🦅
- rigid place coding and behavior in an #Alzheimer's model
- another predator avoidance task, with a taxidermied weasel 👀

Run, don't walk, to read one of my favorite papers this year: www.cell.com/cell-reports...

Flexible updating of reward and punishment contingencies by VTA GABA neurons In dynamic environments where stimuli predicting reward or punishment unexpectedly change, it is critical to flexibly update behavior while preserving…

New lab paper by @merridee.bsky.social identifying a novel role for VTA GABA neurons in behavioral flexibility

GABA, but not dopamine, neuron activation correlates with behavior when cues unexpectedly shift from predicting punishment to predicting reward www.sciencedirect.com/science/arti...

Cell-type-directed network-correcting combination therapy for Alzheimer’s disease A multi-cell-type drug discovery strategy targeting dysregulated gene networks in neurons and glia identified letrozole and irinotecan as a combination therapy that significantly improved memory and r...

The potential for 2 cancer drugs in combination to impact Alzheimer's disease as an outgrowth or single-cell RNA -seq, review of electronic health records from 1.4 million patients, and whittling down 1,300 potential repurposed drugs to 2.
www.cell.com/cell/fulltex...

Burnout is clinically understood as a combo of 6 factors—work overload, lack of control, insufficient rewards, breakdown in community, absence of fairness, & value conflicts—and only a fraction of it is under your control. Burnout is a systemic problem, so be kind to yourself and hard on the system.

Our work, out at Cell, shows that the brain’s dopamine signals teach each individual a unique learning trajectory. Collaborative experiment-theory effort, led by Sam Liebana in the lab. The first experiment my lab started just shy of 6y ago & v excited to see it out: www.cell.com/cell/fulltex...