Publications by authors named "Sarah Heilbronner"

Research on the neural basis of major depressive disorder suggests that it is fundamentally a disease of cortical disinhibition, where breakdowns of inhibitory neuronal systems lead to diminished emotion regulation and intrusive rumination. Subregions of the prefrontal cortex are thought to be sources of this disinhibition. However, due to limited opportunities for intracranial recordings from humans with major depression, this hypothesis has not been directly tested.

View Article and Find Full Text PDF

Free-ranging female African lions maintain symmetrical social relationships by respecting each other's "ownership" of valuable food items rather than by supplanting subordinates according to well-defined dominance hierarchies. However, captivity often skews relationships in captive carnivores, hence we investigated whether captive female lions demonstrate obvious dominance relationships. Oxytocin has been shown to elicit context-specific impacts that equalize dominant subordinate relationships, thus we hypothesized that oxytocin would reduce any asymmetries found between dominants and subordinates in captive lions.

View Article and Find Full Text PDF

The ability to override prepotent actions is critical to control impulses and adjust behavior depending on goals and contextual needs. In this study, we investigate the inhibitory control abilities of a patient diagnosed with Klüver-Bucy Syndrome following a left temporal resection. The patient presented with disruptive hypersexuality symptoms akin to compulsions, leading to the inability to control and suppress inappropriate actions.

View Article and Find Full Text PDF

Importance: Although brain iron is necessary for neurogenesis, myelination, and neurotransmitter synthesis, iron deficiency (ID) is defined solely based on hematological outcomes.

Objective: To examine the association of ID without anemia with basal ganglia (BG) iron content and its structural and functional sequelae in adolescents.

Design, Setting, And Participants: This cross-sectional study enrolled participants using the electronic medical record system from a large network of pediatrics clinics between December 2020 and April 2024.

View Article and Find Full Text PDF

The cingulum bundle (CB) is a group of axons supporting connectivity among several functional brain networks relevant in healthy and diseased states. The paracingulate sulcus (PCS) is present in at least one cerebral hemisphere across 70% of the population. PCS presence versus absence is linked to differences in structure and function of the anterior cingulate cortex, though the influence of PCS on the white matter of the CB remains unknown.

View Article and Find Full Text PDF

Despite their importance for brain function, cortico-subcortical white matter tracts are underrepresented in diffusion MRI tractography studies. Their non-invasive mapping is more challenging and less explored compared to other major cortico-cortical bundles. We introduce a set of standardised tractography protocols for delineating tracts between the cortex and various deep subcortical structures, including the caudate, putamen, amygdala, thalamus and hippocampus.

View Article and Find Full Text PDF

Recent evidence indicates that the intraparietal sulcus (IPS) may play a causal role in action stopping, potentially representing a novel neuromodulation target for inhibitory control dysfunctions. Here, we leverage intracranial recordings in human subjects to establish the timing and directionality of information flow between IPS and prefrontal and cingulate regions during action stopping. Prior to successful inhibition, information flows primarily from the inferior frontal gyrus (IFG), a critical inhibitory control node, to IPS.

View Article and Find Full Text PDF

Psychosis spectrum illnesses are characterized by impaired goal-directed behavior and significant neurophysiological heterogeneity. To investigate the neurocomputational underpinnings of this heterogeneity, 75 participants with Early Psychosis (EP) and 68 controls completed a dynamic decision-making task. Consistent with prior studies, EP exhibited more choice switching, not explained by reward learning deficits, but instead by increased transition to exploration from exploitation.

View Article and Find Full Text PDF

Consciousness is a fundamental component of cognition, but the degree to which higher-order perception relies on it remains disputed. Here we demonstrate the persistence of learning, semantic processing, and online prediction in individuals under general anesthesia-induced loss of consciousness. Using high-density Neuropixels microelectrodes to record neural activity in the human hippocampus while playing a series of tones to anesthetized patients, we found that hippocampal neurons could reliably detect oddball tones.

View Article and Find Full Text PDF

Significance: We introduce a visible-light polarization-sensitive optical coherence tomography (PS-OCT) system that operates in the spectral domain with balanced detection (BD) capability. While the BD improves the signal-to-noise ratio (SNR), the use of shorter wavelengths improves spatial resolution and birefringence sensitivity.

Aim: We aim to implement a new optical design, characterize its performance, and investigate the imaging potential for biological tissues.

View Article and Find Full Text PDF

Recent evidence indicates that the intraparietal sulcus (IPS) may play a causal role in action stopping, potentially representing a novel neuromodulation target for inhibitory control dysfunctions. Here, we leverage intracranial recordings in human subjects to establish the timing and directionality of information flow between IPS and prefrontal and cingulate regions during action stopping. Prior to successful inhibition, information flows primarily from the inferior frontal gyrus (IFG), a critical inhibitory control node, to IPS.

View Article and Find Full Text PDF

Deep brain stimulation (DBS) of the ventral capsule and ventral striatum (VC/VS) is an effective therapy for treatment resistant obsessive-compulsive disorder (trOCD). DBS initiation often produces acute improvements in mood and energy. These acute behavioral changes, which we refer to as "approach behaviors", include increased social engagement and talkativeness.

View Article and Find Full Text PDF
Article Synopsis
  • Obsessive-compulsive disorder (OCD) can be challenging to treat, especially in severe cases that don't respond to standard medications or therapy, leading to surgical options like deep brain stimulation (DBS) and lesioning.
  • Two patients with severe OCD who had previously failed to benefit from anterior capsulotomy underwent DBS and showed significant improvements in their symptoms, with reductions in YBOCS scores of 37% and 47%.
  • This study suggests that DBS can be an effective surgical option for OCD even after other procedures have not worked, highlighting the flexibility of treatment approaches.
View Article and Find Full Text PDF

Understanding the neural basis of major depressive disorder (MDD) is vital to guiding neuromodulatory treatments. The available evidence supports the hypothesis that MDD is fundamentally a disease of cortical disinhibition, where breakdowns of inhibitory neural systems lead to diminished emotion regulation and intrusive ruminations. Recent research also points towards network changes in the brain, especially within the prefrontal cortex (PFC), as primary sources of MDD etiology.

View Article and Find Full Text PDF

A systematic review of functional neuroimaging studies on drug (self-) administration in rodents is lacking. Here, we summarized effects of acute or chronic drug administration of various classes of drugs on brain function and determined consistency with human literature. We performed a systematic literature search and identified 125 studies on in vivo rodent resting-state functional magnetic resonance imaging (n = 84) or positron emission tomography (n = 41) spanning depressants (n = 27), opioids (n = 23), stimulants (n = 72), and cannabis (n = 3).

View Article and Find Full Text PDF

Background: The anterior limb of the internal capsule (ALIC) is a white matter structure that connects the prefrontal cortex (PFC) to the brainstem, thalamus, and subthalamic nucleus. It is a target for deep brain stimulation for obsessive-compulsive disorder. There is strong interest in improving deep brain stimulation targeting by using diffusion tractography to reconstruct and target specific ALIC fiber pathways, but this methodology is susceptible to errors and lacks validation.

View Article and Find Full Text PDF

Background: Single-pulse electrical stimulation (SPES) is an established technique used to map functional effective connectivity networks in treatment-refractory epilepsy patients undergoing intracranial-electroencephalography monitoring. While the connectivity path between stimulation and recording sites has been explored through the integration of structural connectivity, there are substantial gaps, such that new modeling approaches may advance our understanding of connectivity derived from SPES studies.

New Method: Using intracranial electrophysiology data recorded from a single patient undergoing stereo-electroencephalography (sEEG) evaluation, we employ an automated detection method to identify early response components, C1, from pulse-evoked potentials (PEPs) induced by SPES.

View Article and Find Full Text PDF

Background: Single-pulse electrical stimulation (SPES) is an established technique used to map functional effective connectivity networks in treatment-refractory epilepsy patients undergoing intracranial-electroencephalography monitoring. While the connectivity path between stimulation and recording sites has been explored through the integration of structural connectivity, there are substantial gaps, such that new modeling approaches may advance our understanding of connectivity derived from SPES studies.

New Method: Using intracranial electrophysiology data recorded from a single patient undergoing sEEG evaluation, we employ an automated detection method to identify early response components, C1, from pulse-evoked potentials (PEPs) induced by SPES.

View Article and Find Full Text PDF

Non-human primates (NHPs) have become key for translational research in noninvasive brain stimulation (NIBS). However, in order to create comparable stimulation conditions for humans it is vital to study the accuracy of current modeling practices across species. Numerical models to simulate electric fields are an important tool for experimental planning in NHPs and translation to human studies.

View Article and Find Full Text PDF

Human neuroimaging has demonstrated the existence of large-scale functional networks in the cerebral cortex consisting of topographically distant brain regions with functionally correlated activity. The salience network (SN), which is involved in detecting salient stimuli and mediating inter-network communication, is a crucial functional network that is disrupted in addiction. Individuals with addiction display dysfunctional structural and functional connectivity of the SN.

View Article and Find Full Text PDF

Introduction: Huntington's disease (HD) is a neurodegenerative disease that primarily affects the striatum, a brain region that controls movement and some forms of cognition. Neuronal dysfunction and loss in HD is accompanied by increased astrocyte density and astrocyte pathology. Astrocytes are a heterogeneous population classified into multiple subtypes depending on the expression of different gene markers.

View Article and Find Full Text PDF

Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) are engineered receptors that allow for genetically targeted, reversible manipulation of cellular activity via systemic drug administration. DREADD induced manipulations are initiated via the binding of an actuator ligand. Therefore, the use of DREADDs is contingent on the availability of actuator ligands.

View Article and Find Full Text PDF

The posterior cingulate cortex (PCC) is one of the least understood regions of the cerebral cortex. By contrast, the anterior cingulate cortex has been the subject of intensive investigation in humans and model animal systems, leading to detailed behavioural and computational theoretical accounts of its function. The time is right for similar progress to be made in the PCC given its unique anatomical and physiological properties and demonstrably important contributions to higher cognitive functions and brain diseases.

View Article and Find Full Text PDF