Sensory Thalamus Research Articles

Foundations of Magnetic Resonance-Guided Focused Ultrasonography

The ability of ultrasonography to safely penetrate deeply into the brain has made it an attractive technology for neurological applications for almost 1 century. Having recognized that converging ultrasound waves could deliver high levels of energy to a target and spare the overlying and surrounding brain, early applications used craniotomies to allow transducers to contact the brain or dural surface. The development of transducer arrays that could permit the transit of sufficient numbers of ultrasound waves to deliver high energies to a target, even with the loss of energy from the skull, has now resulted in clinical systems that can permit noninvasive focused ultrasound procedures that leave the skull intact. Another major milestone in the field was the marriage of focused ultrasonography with magnetic resonance thermometry. This provides real-time feedback regarding the level and location of brain tissue heating, allowing for precise elevation of temperatures within a desired target to lead to focal therapeutic lesions. The major clinical use of this technology, at present, has been limited to treatment of refractory essential tremor and parkinsonian tremor, although the first study of this approach had targeted sensory thalamus for refractory pain, and new targets and disease indications are under study. Finally, focused ultrasonography can also be used at a lower frequency and energy level when combined with intravenous microbubbles to create cavitations, which will open the blood-brain barrier rather than ablate tissue. In the present review, we have discussed the historical and scientific foundations and current clinical applications of magnetic resonance-guided focused ultrasonography and the genesis and background that led to the use of this technique for focal blood-brain barrier disruption.

Developmental divergence of sensory stimulus representation in cortical interneurons

Vasocative-intestinal-peptide (VIP+) and somatostatin (SST+) interneurons are involved in modulating barrel cortex activity and perception during active whisking. Here we identify a developmental transition point of structural and functional rearrangements onto these interneurons around the start of active sensation at P14. Using in vivo two-photon Ca2+ imaging, we find that before P14, both interneuron types respond stronger to a multi-whisker stimulus, whereas after P14 their responses diverge, with VIP+ cells losing their multi-whisker preference and SST+ neurons enhancing theirs. Additionally, we find that Ca2+ signaling dynamics increase in precision as the cells and network mature. Rabies virus tracings followed by tissue clearing, as well as photostimulation-coupled electrophysiology reveal that SST+ cells receive higher cross-barrel inputs compared to VIP+ neurons at both time points. In addition, whereas prior to P14 both cell types receive direct input from the sensory thalamus, after P14 VIP+ cells show reduced inputs and SST+ cells largely shift to motor-related thalamic nuclei.

Focused Ultrasound Thalamotomy Sensory Side Effects Follow the Thalamic Structural Homunculus.

Focused ultrasound thalamotomy is an effective treatment for tremor; however, side effects may occur. The purpose of the present study was to investigate the spatial relationship between thalamotomies and specific sensory side effects and their functional connectivity with somatosensory cortex and relationship to the medial lemniscus (ML). Sensory adverse effects were categorized into 4 groups based on the location of the disturbance: face/mouth/tongue numbness/paresthesia, hand-only paresthesia, hemibody/limb paresthesia, and dysgeusia. Then, areas of significant risk (ASRs) for each category were defined using voxel-wise mass univariate analysis and overlaid on corresponding odds ratio maps. The ASR associated with the maximum risk was used as a region of interest in a normative functional connectome to determine side effect-specific functional connectivity. Finally, each ASR was overlaid on the ML derived from normative template. Of 103 patients, 17 developed sensory side effects after thalamotomy persisting 3 months after the procedures. Lesions producing sensory side effects extended posteriorly into the principle sensory nucleus of the thalamus or below the thalamus in the ML. The topography of sensory adverse effects followed the known somatotopy of the ML and the sensory nucleus. Functional connectivity patterns between each sensory-specific thalamic seed and the primary somatosensory areas supported the role of the middle insula in processing of gustatory information and in multisensory integration. Distinct regions in the sensory thalamus and its afferent connections rise to specific sensory disturbances. These findings demonstrate the relationship between the sensory thalamus, ML, and bilateral sensory cortical areas.

Pallidal Connectivity Profiling of Stimulation-Induced Dyskinesia in Parkinson's Disease.

The aim of this study is to identify anatomical regions related to stimulation-induced dyskinesia (SID) after pallidal deep brain stimulation (DBS) in Parkinson's disease (PD) patients and to analyze connectivity associated with SID. This retrospective study analyzed the clinical and imaging data of PD patients who experienced SID during the monopolar review after pallidal DBS. We analyzed structural and functional connectivity using normative connectivity data with the volume of tissue activated (VTA) modeling. Each contact was assigned to either that producing SID (SID VTA) or that without SID (non-SID VTA). Structural and functional connectivity was compared between SID and non-SID VTAs. "Optimized VTAs" were also estimated using the DBS settings at 6 months after implantation. Of the 68 consecutive PD patients who underwent pallidal implantation, 20 patients (29%) experienced SID. SID VTAs were located more dorsally and anteriorly compared with non-SID and optimized VTAs and were primarily in the dorsal globus pallidus internus (GPi) and dorsal globus pallidus externus (GPe). SID VTAs showed significantly higher structural connectivity than non-SID VTAs to the associative cortex and supplementary motor area/premotor cortex (P < 0.0001). Simultaneously, non-SID VTAs showed greater connectivity to the primary sensory cortex, cerebellum, subthalamic nucleus, and motor thalamus (all P < 0.0004). Functional connectivity analysis showed significant differences between SID and non-SID VTAs in multiple regions, including the primary motor, premotor, and prefrontal cortices and cerebellum. SID VTAs were primarily in the dorsal GPi/GPe. The connectivity difference between the motor-related cortices and subcortical regions may explain the presence and absence of SID. © 2020 International Parkinson and Movement Disorder Society.

Publisher Correction: Two dynamically distinct circuits drive inhibition in the sensory thalamus

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Two dynamically distinct circuits drive inhibition in the sensory thalamus.

Most sensory information destined for the neocortex is relayed through the thalamus, where considerable transformation occurs1,2. One powerful means of transformation involves interactions between excitatory thalamocortical neurons that carry data to cortex and inhibitory neurons of the thalamic reticular nucleus (TRN) that regulate flow of those data3–6. Despite enduring recognition of its importance7–9, understanding of TRN cell types, their organization, and their functional properties has lagged that of the thalamocortical systems they control.Here we address this, investigating somatosensory and visual circuits of the TRN. In the somatosensory TRN we observed two groups of genetically defined neurons that are topographically segregated, physiologically distinct, and connect reciprocally with independent thalamocortical nuclei via dynamically divergent synapses. Calbindin-expressing cells, located in the central core, connect with the ventral posterior nucleus (VP), the primary somatosensory thalamocortical relay. In contrast, somatostatin-expressing cells, residing along the surrounding edges of TRN, synapse with the posterior medial thalamic nucleus (POM), a higher-order structure that carries both top-down and bottom-up information10–12. The two TRN cell groups process their inputs in pathway-specific ways. Synapses from VP to central TRN cells transmit rapid excitatory currents that depress deeply during repetitive activity, driving phasic spike output. Synapses from POM to edge TRN cells evoke slower, less depressing excitatory currents that drive more persistent spiking. Differences in intrinsic physiology of TRN cell types, including state-dependent bursting, contribute to these output dynamics. Thus, processing specializations of two somatosensory TRN subcircuits appear to be tuned to the signals they carry—a primary central subcircuit to discrete sensory events, and a higher-order edge subcircuit to temporally distributed signals integrated from multiple sources. The structure and function of visual TRN subcircuits closely resemble those of the somatosensory TRN. These results provide fundamental insights about how subnetworks of TRN neurons may differentially process distinct classes of thalamic information.

Chemogenetic silencing of neurons in the mouse anterior cingulate area modulates neuronal activity and functional connectivity

The anterior cingulate area (ACC) is an integral part of the prefrontal cortex in mice and supports cognitive functions, including attentional processes, motion planning and execution as well as remote memory, fear and pain. Previous anatomical and functional imaging studies demonstrated that the ACC is interconnected with numerous brain regions, such as motor and sensory cortices, amygdala and limbic areas, suggesting it serves as a hub in functional networks. However, the exact role of the ACC in regulating functional network activity and connectivity remains to be elucidated. Recently developed neuromodulatory techniques, such as Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) allow for precise control of neuronal activity. In this study, we used an inhibitory kappa-opioid receptor DREADD (KORD) to temporally inhibit neuronal firing in the right ACC of mice and assessed functional network activity and connectivity using non-invasive functional magnetic resonance imaging (MRI). We demonstrated that KORD-induced inhibition of the right ACC induced blood oxygenation-level dependent (BOLD) signal decreases and increases in connected brain regions of both hemispheres. More specifically, altered neuronal activity could be observed in functional brain networks including connections with sensory cortex, thalamus, basolateral amygdala and ventral pallidum, areas involved in attention processes, working memory, fear behavior and reward respectively. Furthermore, these modulations in neuronal activity were associated with decreased intra- and interhemispheric functional connectivity. Our results consolidate the hub role of the mouse ACC in functional networks and further demonstrate that the combination of the DREADD technology and non-invasive functional imaging methods is a valuable tool for unraveling mechanisms of network function and dysfunction by reversible inactivation of selected targets.

Traumatic Re-Experiencing and Anxious Arousal Symptoms in Relation to Volumes of Sensory Thalamic Nuclei

Trauma re-experiencing is often dominated by recollection of sensory-perceptual elements of the trauma, pointing to involvement of the sensory thalamus. This study examined re-experiencing symptoms in relation to volumes of thalamic nuclei implicated in sensory information processing. We hypothesized that re-experiencing, controlling for other posttraumatic symptom dimensions, would be significantly associated with volumes of the pulvinar nuclei (visual salience), ventroposterolateral nuclei (VPL: somatosensory), and lateral and medial geniculate nuclei (LGN, MGN: primary visual and auditory relays).

Role of the Thalamus in Basal Forebrain Regulation of Neural Activity in the Primary Auditory Cortex.

Many studies have implicated the basal forebrain (BF) as a potent regulator of sensory encoding even at the earliest stages of or cortical processing. The source of this regulation involves the well-documented corticopetal cholinergic projections from BF to primary cortical areas. However, the BF also projects to subcortical structures, including the thalamic reticular nucleus (TRN), which has abundant reciprocal connections with sensory thalamus. Here we present naturalistic auditory stimuli to the anesthetized rat while making simultaneous single-unit recordings from the ventral medial geniculate nucleus (MGN) and primary auditory cortex (A1) during electrical stimulation of the BF. Like primary visual cortex, we find that BF stimulation increases the trial-to-trial reliability of A1 neurons, and we relate these results to change in the response properties of MGN neurons. We discuss several lines of evidence that implicate the BF to thalamus pathway in the manifestation of BF-induced changes to cortical sensory processing and support our conclusions with supplementary TRN recordings, as well as studies in awake animals showing a strong relationship between endogenous BF activity and A1 reliability. Our findings suggest that the BF subcortical projections that modulate MGN play an important role in auditory processing.

Comprehensive mapping of cytochrome c oxidase activity in the rat brain after sub-chronic ketamine administration

Ketamine is a noncompetitive antagonist of glutamatergic N-methyl-d-aspartate receptors. Its acute effects on healthy volunteers and schizophrenia patients mimic some acute psychotic, but also cognitive and negative symptoms of schizophrenia, and subchronic treatment with ketamine has been used as an animal model of psychotic disorders. Glutamatergic neurotransmission is tightly coupled to oxidative metabolism in the brain. Quantitative histochemical mapping of cytochrome c oxidase (COX) activity, which reflect long-term energy metabolism, was carried out in rats that received a daily subanaesthetic dose (30 mg/kg) of ketamine for 10 days. In total, COX activity was measured in 190 brain regions to map out metabolic adaptations to the subchronic administration of ketamine. Ketamine treatment was associated with elevated COX activity in nine brain sub-regions in sensory thalamus, basal ganglia, cortical areas, hippocampus and superior colliculi. Changes in pairwise correlations between brain regions were studied with differential correlation analysis. Ketamine treatment was associated with the reduction of positive association between brain regions in 66 % of the significant comparisons. Different layers of the superior colliculi showed the strongest effects. Changes in other visual and auditory brain centres were also of note. The locus coeruleus showed opposite pattern of increased coupling to mainly limbic brain regions in ketamine-treated rats. Our study replicated commonly observed activating effects of ketamine in the hippocampus, cingulate cortex, and basal ganglia. The current study is the first to extensively map the oxidative metabolism in the CNS in the ketamine model of schizophrenia. It shows that ketamine treatment leads to the re-organization of activity in sensory and memory-related brain circuits.

Two genetically, anatomically and functionally distinct cell types segregate across anteroposterior axis of paraventricular thalamus.

Unlike sensory thalamus, studies on the functional organization of midline and intralaminar nuclei are scarce, and this has hampered the establishment of conceptual models on the function of this brain region. We have investigated the functional organization of the paraventricular nucleus of the thalamus (PVT), a midline thalamic structure increasingly being recognized as a critical node in the control of diverse processes such as arousal, stress, emotional memory and motivation, in mice. We identify two major classes of PVT neurons – termed Type I and Type II – that differ in terms of gene expression, anatomy and function. In addition, we demonstrate that Type II neurons belong to a previously neglected class of PVT neurons that conveys arousal-related information to corticothalamic neurons of the infralimbic cortex. Our results uncover the existence of an arousal-modulated thalamo-corticothalamic loop that links the PVT and the ventromedial prefrontal cortex.

Deep Brain Stimulation and Motor Cortex Stimulation for Chronic Pain.

Deep brain stimulation (DBS) and Motor Cortex stimulation (MCS) have been used for control of chronic pain. Chronic pain of any origin is complex and difficult to treat. Stimulation of various areas in brain-like sensory thalamus, medial nuclei of thalamus including centro-lateral nucleus of thalamus (CL), periaqueductal gray, periventricular gray, nucleus accumbence and motor cortex provides partial relief in properly selected patients. This article reviews the pain pathways, theories of pain, targets for DBS and rationale of DBS and MCS. It also discusses the patient selection, technical details of each target.

The metabotropic glutamate receptor subtype 1 regulates development and maintenance of lemniscal synaptic connectivity in the somatosensory thalamus.

The metabotropic glutamate receptor subtype 1 (mGluR1) is a major subtype of group I mGluRs, which contributes to the development and plasticity of synapses in the brain. In the sensory thalamus, the thalamocortical neuron receives sensory afferents and massive feedback input from corticothalamic (CT) fibers. Notably, mGluR1 is more concentrated in CT synapses in the sensory thalamus. In the visual thalamus, mGluR1 maintains mature afferent synaptic connectivity. However, it is unknown whether mGluR1 contributes to strengthening of immature synapses or weakening of excess synapses during development and whether mGluR1 at CT synapses heterosynaptically regulates the development or refinement of afferent synapses. Here we investigated the effects of knocking out the gene encoding mGluR1 or pharmacologically blocking cortical activity on the development and maintenance of lemniscal synapses, i.e., the somatosensory afferent synapses, in the ventral posteromedial somatosensory thalamus. mGluR1-knockout (KO) mice exhibited delayed developmental strengthening as well as incomplete elimination and remodeling after maturation of lemniscal synapses. Similar to the phenotypes exhibited by mGluR1-KO mice, pharmacological blockade of somatosensory cortical activity from P12 or P21 for 1 week in wild-type mice perturbed elimination or maintenance of lemniscal synapses, respectively. The same manipulation in mGluR1-KO mice failed to induce additional abnormalities in lemniscal synaptic connectivity. These results suggest that activation of mGluR1, driven by CT input, regulates multiple stages of the development of lemniscal synapses, including strengthening, refinement, and maintenance in the somatosensory thalamus.

Functional dynamics of thalamic local field potentials correlate with modulation of neuropathic pain.

Understanding the functional dynamics of neural oscillations in the sensory thalamus is essential for elucidating the perception and modulation of neuropathic pain. Local field potentials were recorded from the sensory thalamus of twelve neuropathic pain patients. Single and combinational neural states were defined by the activity state of a single or paired oscillations. Relationships between the duration or occurrence rate of neural state and pre-operative pain level or pain relief induced by deep brain stimulation were evaluated. Results showed that the occurrence rate of the single neural state of low-beta oscillation was significantly correlated with pain relief. The duration and occurrence rate of combinational neural states of the paired low-beta with delta, theta, alpha, high-beta or low-gamma oscillations were more significantly correlated with pain relief than the single neural states. Moreover, these significant combinational neural states formed a local oscillatory network with low-beta oscillation as a key node. The results also showed correlations between measures of combinational neural states and subjective pain level as well. The duration of combinational neural states of paired alpha with delta or theta oscillations and the occurrence rate of neural states of the paired delta with low-beta or low-gamma oscillations were significantly correlated with pre-operative pain level. In conclusion, this study revealed that the integration of oscillations and the functional dynamics of neural states were differentially involved in modulation and perception of neuropathic pain. The functional dynamics could be biomarkers for developing neural state-dependent deep brain stimulation for neuropathic pain.

Modulation of tonotopic ventral medial geniculate body is behaviorally relevant for speech recognition.

Sensory thalami are central sensory pathway stations for information processing. Their role for human cognition and perception, however, remains unclear. Recent evidence suggests an involvement of the sensory thalami in speech recognition. In particular, the auditory thalamus (medial geniculate body, MGB) response is modulated by speech recognition tasks and the amount of this task-dependent modulation is associated with speech recognition abilities. Here, we tested the specific hypothesis that this behaviorally relevant modulation is present in the MGB subsection that corresponds to the primary auditory pathway (i.e., the ventral MGB [vMGB]). We used ultra-high field 7T fMRI to identify the vMGB, and found a significant positive correlation between the amount of task-dependent modulation and the speech recognition performance across participants within left vMGB, but not within the other MGB subsections. These results imply that modulation of thalamic driving input to the auditory cortex facilitates speech recognition.

Whisker-Mediated Touch System in Rodents: From Neuron to Behavior.

A key question in systems neuroscience is to identify how sensory stimuli are represented in neuronal activity, and how the activity of sensory neurons in turn is “read out” by downstream neurons and give rise to behavior. The choice of a proper model system to address these questions, is therefore a crucial step. Over the past decade, the increasingly powerful array of experimental approaches that has become available in non-primate models (e.g., optogenetics and two-photon imaging) has spurred a renewed interest for the use of rodent models in systems neuroscience research. Here, I introduce the rodent whisker-mediated touch system as a structurally well-established and well-organized model system which, despite its simplicity, gives rise to complex behaviors. This system serves as a behaviorally efficient model system; known as nocturnal animals, along with their olfaction, rodents rely on their whisker-mediated touch system to collect information about their surrounding environment. Moreover, this system represents a well-studied circuitry with a somatotopic organization. At every stage of processing, one can identify anatomical and functional topographic maps of whiskers; “barrelettes” in the brainstem nuclei, “barreloids” in the sensory thalamus, and “barrels” in the cortex. This article provides a brief review on the basic anatomy and function of the whisker system in rodents.

One or two minds? Neural network modeling of decision making by the unified self

Ever since the seminal work of Tversky and Kahneman starting in the late 1960s, it has generally been accepted that many characteristic human decision patterns do not follow the norms of economic theories based on rational utility maximization and consistency across frames. Yet people do often make decisions and numerical judgments that are mathematically consistent. In order to account for the range of rational, intuitive, and emotional influences on decision making, prominent psychologists have developed a number of dual-process or dual-system theories of decision processes. Among these theories are System 1 and System 2, Cognitive-Experiential Self-theory, and Fuzzy Trace Theory. Fuzzy Trace Theory (FTT) is the most amenable of these theories to a unified biologically based neural network approach. This article reviews several years of research on a decision theory that integrates the gist and verbatim representations of FTT into a network model. The model is based on several constructs by Grossberg and his colleagues including Adaptive Resonance Theory and Gated Dipole Theory, combined with selective attention and probabilistic distribution of some parameters representing individual differences in decision style. It incorporates data on the functions of several brain regions including sensory cortex, amygdala, orbitofrontal cortex, ventral striatum, thalamus, and anterior cingulate, and premotor cortex.

A new potential specifically marks the sensory thalamus in anaesthetised patients

ObjectiveDuring deep brain stimulation (DBS) surgery, we analysed somatosensory evoked potentials (SSEPs) using microelectrode recordings (MERs) in patients under general anaesthesia. MethodsWe obtained MERs from 5 patients with refractory epilepsy. Off-line analysis isolated local field potentials (LFPs, 2–200 Hz) and high frequency components (HFCs, 0.5–5 kHz). Trajectories were reconstructed off-line. ResultsThe ventral caudate (V.c.) nucleus was most frequently recorded from (171 mm). Very high frequency oscillations (VHFOs) were recorded up to 8 mm in length from all 4 electrodes but were most frequently recorded from the V.c. The properties of VHFOs were similar among all nuclei (frequency >1500 Hz, amplitude ∼3 µV, starting time ∼14 ms, duration 8–9 ms). Consecutive recordings did not show any synchronization or propagation, but a new kind of potential (high frequency oscillation, HFO) appeared abruptly inside the V.c. (frequency = 848 ± 66 Hz, amplitude = 5.2 ± 1.8 µV starting at 17.7 ± 0.5 ms, spanning 3.4 ± 0.3 ms). ConclusionsVHFOs are widely extending and cannot be ascribed to the V.c. HFOs in patients under general anaesthesia can serve as a landmark to identify the V.c. in thalamic DBS surgery. SignificanceThalamic processing involves nuclei other than the V.c, and HFO can be used to improve DBS surgery.

Applying Dimensional Psychopathology: The Transdiagnostic Link between Somatic Depressive Symptoms, Brain Connectivity, and Leptin

Background: Dimensional psychopathology and its neurobiological underpinnings could provide important insight into the major psychiatric disorders (MPDs), including major depressive disorder (MDD), bipolar disorder (BPD), and schizophrenia (SCZ). In this study, we examined depressive symptoms and their relationship with functional connectivity (FC) and leptin across MPDs. Methods: A total of 728 participants [healthy controls (HC), n = 325; MDD, n = 153; BPD, n = 123; SCZ, n = 127] underwent resting state functional magnetic resonance imaging at a single site. Plasma leptin levels and depressive symptom measures (Hamilton Depression Rating Scale, HAMD) were obtained within 24 hours of scan. Factor analyses were used to identify HAMD factor scores. Regional FC and plasma leptin levels were compared between MPDs and HC. Mediational analyses were performed to determine the relationship between regional FC, plasma leptin levels, and HAMD factor scores. Findings: We found that depressive symptoms were associated with regional FC decreases in primary sensory and association cortices and thalamus, regional FC increases in the prefrontal cortex and angular gyrus, and elevated leptin levels across MPDs, compared to HC. Mediation analyses showed that plasma leptin level mediates the relationship between regional FC alterations in primary somatosensory cortex and somatic depressive symptoms. Interpretation: Our findings support a role of the primary somatosensory cortex in depressive symptoms across MPDs. Further, leptin appears to be an important link between brain connectivity alterations in this region and somatic depressive symptoms, suggesting a potential therapeutic target for depressive symptoms in patients with MPDs. Funding: This study was funded by National Science Fund for Distinguished Young Scholars (81725005 to F.W.), National Natural Science Foundation of China (81571311 to Y.T., 81571331 to F.W.), National Key Research and Development Program (2018YFC1311604 to Y.T., 2016YFC1306900 to Y.T., 2016YFC0904300 to F.W.), National High Tech Development Plan (863) (2015AA020513 to F.W.), Liaoning Science and Technology Project (2015225018 to Y.T.), Liaoning Education Foundation (Pandeng Scholar to F.W.), Innovation Team Support Plan of Higher Education of Liaoning Provience (LT2017007 to F.W.), and Major Special Construction plan of China Medical University (3110117059 to F.W.). Declaration of Interest: The authors report no biomedical financial interests or potential conflicts of interest. Ethical Approval: The study was approved by the Institutional Review Board of the China Medical University and was conducted in accordance with the Declaration of Helsinki. Participants provided written informed consent. All the experiments and methods were carried out in accordance with approved regulations and guidelines.

Sensory thalamus and periaqueductal grey area local field potential signals during bladder filling

The periaqueductal grey area and sensory thalamus are thought to be important nuclei involved in the supraspinal bladder control network. Deep brain stimulation of the periqueductal grey area has been shown to increase bladder capacity in the human. In a single patient, we have recorded local field potential signals from implanted deep brain stimulation electrodes within the sensory thalamus during filling cystometry with periaqueductal grey area deep brain stimulation in the ON and OFF states. In the OFF stimulation state, we demonstrate correlations between bladder volume and oscillations in the high gamma frequency band in the sensory thalamus. Stimulation of the periaqueductal grey area abolishes this correlated activity in the gamma frequency band and also suppresses oscillations within the sensory thalamus in the alpha frequency band. These findings support the involvement of the sensory thalamus in the afferent limb of bladder-related brain networks. They also suggest that periaqueductal grey area deep brain stimulation may disrupt the normal processing of afferent signals within the sensory thalamus which may be related to the effect of stimulation on bladder capacity.