Biology subjects

Bateman, L. M.

Publications and source records attributed to Bateman, L. M..

5 recordsLinked to original sources

bioRxiv2026

Criterion-selective neurons in the human medial frontal cortex track decision thresholds during memory-based decision making

The decision criterion is foundational to theories of decision-making, yet little is known about its neural underpinnings. In memory-based decision making, the criterion sets the minimal memory strength for something to be familiar, but whether or how it is distinctly represented from memory strength is unknown. We recorded single neurons in the medial frontal cortex (MFC) and medial temporal lobe (MTL), both implicated in memory-based decisions, while participants made decisions under different decision criteria. We identified criterion-selective (CS) neurons in the MFC that tracked the criterion regardless of memory strength, and memory-selective (MS) neurons in both regions that tracked memory strength regardless of the criterion. CS neurons signaled the criterion before MS neurons signaled memory strength, and a race model incorporating both neuron types outperformed one using MS neurons alone. These findings reveal two independent cellular substrates, one for the decision criterion and one for memory strength, whose joint activity underlies memory-based decisions.

neuroscience↗

bioRxiv2026

Human serum triglycerides promote Staphylococcus aureus biofilm formation and antibiotic tolerance

Biofilm formation and antibiotic tolerance are major contributors to the persistence of Staphylococcus aureus infections, yet how the host environment affects these phenotypes remains poorly understood. Here, we show that incubation in human serum primes S. aureus to form robust biofilms and tolerate vancomycin and daptomycin, last resort antibiotics for the treatment of antibiotic-resistant staphylococcal infections. Mechanistically, we demonstrate that the staphylococcal Geh lipase is essential for serum-induced biofilm formation by liberating glycerol from host lipids, which is then used to promote increased synthesis of D-alanylated wall teichoic acids, driving biofilm development. Inhibition of the Geh lipase or wall teichoic acid synthesis markedly reduces biofilm formation and restores antibiotic susceptibility, highlighting clinically achievable strategies to inhibit host-induced biofilm formation and prevent the associated antibiotic tolerance. Together, our findings reveal a host-driven mechanism of biofilm-associated antibiotic tolerance in S. aureus and provide rational targets for therapeutic intervention.

microbiology↗

bioRxiv2024

A shared code for perceiving and imagining objects in human ventral temporal cortex

Mental imagery is a remarkable phenomenon that allows us to remember previous experiences and imagine new ones. Animal studies have yielded rich insight into mechanisms for visual perception, but the neural mechanisms for visual imagery remain poorly understood. Here, we first determined that [~]80% of visually responsive single neurons in human ventral temporal cortex (VTC) use a distributed axis code to represent objects. We then used that code to reconstruct objects and generate maximally effective synthetic stimuli. Finally, we recorded responses from the same neural population while subjects imagined specific objects and found that [~]40% of axis-tuned VTC neurons recapitulated the visual code. Our findings reveal that visual imagery is supported by reactivation of the same neurons involved in perception, providing single neuron evidence for the existence of a generative model in human VTC. One Sentence SummarySingle neurons in human temporal cortex use feature axes to encode objects, and imagery reactivates this code.

neuroscience↗

bioRxiv2020

Neuronal firing and waveform alterations through ictal recruitment in humans

AO_SCPLOWBSTRACTC_SCPLOWClinical analyses of neuronal activity during seizures, invariably using extracellular recordings, is greatly hindered by various phenomena that are well established in animal studies: changes in local ionic concentration, changes in ionic conductance, and intense, hypersynchronous firing. The first two alter the action potential waveform, whereas the third increases the "noise"; all three factors confound attempts to detect and classify single neurons (units). To address these analytical difficulties, we developed a novel template-matching based spike sorting method, which enabled identification of 1,239 single units in 27 patients with intractable focal epilepsy, that were tracked throughout multiple seizures. These new analyses showed continued neuronal firing through the ictal transition, which was defined as a transient period of intense tonic firing consistent with previous descriptions of the ictal wavefront. After the ictal transition, neurons displayed increased spike duration (p < 0.001) and reduced spike amplitude (p < 0.001), in keeping with prior animal studies; units in non-recruited territories, by contrast, showed more stable waveforms. All units returned to their pre-ictal waveforms after seizure termination. Waveshape changes were stereotyped across seizures within patients. Our analyses of single neuron firing patterns, at the ictal wavefront, showed widespread intense activation, and commonly involving marked waveshape alteration. We conclude that the distinction between tissue that has been recruited to the seizure versus non-recruited territories is evident at the level of single neurons, and that increased waveform duration and decreased waveform amplitude are hallmarks of seizure invasion that could be used as defining characteristics of local recruitment. SO_SCPLOWIGNIFICANCEC_SCPLOW SO_SCPLOWTATEMENTC_SCPLOWAnimal studies consistently show marked changes in action potential waveform during epileptic discharges, but acquiring similar evidence in humans has proved difficult. Assessing neuronal involvement in ictal events is pivotal to understanding seizure dynamics and in defining clinical localization of epileptic pathology. Using a novel method to track neuronal firing, we analyzed microelectrode array recordings of spontaneously occurring human seizures, and here report two dichotomous activity patterns. In cortex that is recruited to the seizure, neuronal firing rates increase and waveforms become longer in duration and shorter in amplitude, while penumbral tissue shows stable action potentials, in keeping with the "dual territory" model of seizure dynamics.

neuroscience↗

bioRxiv2019

A theoretical model for focal seizure initiation, propagation, termination, and progression

We developed a neural network model that can account for the major elements common to human focal seizures. These include the tonic-clonic transition, slow advance of clinical semiology and corresponding seizure territory expansion, widespread EEG synchronization, and slowing of the ictal rhythm as the seizure approaches termination. These were reproduced by incorporating usage-dependent exhaustion of inhibition in an adaptive neural network that receives global feedback inhibition in addition to local recurrent projections. Our model proposes mechanisms that may underline common EEG seizure onset patterns and status epilepticus and postulates a role for synaptic plasticity in emergence of epileptic foci. Complex patterns of seizure activity and bi-stable seizure evolution end-points arise when stochastic noise is included. With the rapid advancement of clinical and experimental tools, we believe that this can provide a roadmap and potentially a testbed for future explorations of seizure mechanisms and clinical therapies.

neuroscience↗