Microelectrode recording characterization of the nucleus accumbens and the anterior limb of internal capsule in patients with addiction.

The nucleus accumbens (NAc) and the anterior limb of internal capsule (ALIC) are effective targets for treating addiction using deep brain stimulation (DBS). However, there have been no reports on the electrophysiological characteristics of addiction nuclei at the single-cell level in humans. This study aimed to investigate the electrical activity characteristics of neurons in the NAc and ALIC using microelectrode recording (MER) during DBS surgery in patients with addiction, and six patients with addiction were included (five with heroin addiction and one with alcohol addiction). The microelectrode recording trajectories were reconstructed and recording sites at different depths were determined by merging the pre- and post-operative images in the FrameLink system. The results showed that among the 256 neurons, 204 (80 %) were burst neurons. NAc neurons accounted for the majority (57 %), and the mean firing rate (MFR) was the highest (1.94 Hz). ALIC neurons accounted for the least (14 %), and MFR was the lowest (0.44 Hz). MFR increased after entering the NAc and decreased after entering the ALIC. In the patients with addiction treated using DBS, the single-cell level electrophysiological characteristics of the different nuclei were found to be distinct along the surgical trajectory.

Brain Motor Region Diffusion Tensor Imaging in Patients with Catatonic Schizophrenia: A Case-Control Study.

BACKGROUND: Only a small proportion of schizophrenia patients present with catatonic symptoms. Imaging studies suggest that brain motor circuits are involved in the underlying pathology of catatonia. However, data about diffusivity dysregulation of these circuits in catatonic schizophrenia are scarce. OBJECTIVES: To assess the involvement of brain motor circuits in schizophrenia patients with catatonia. METHODS: Diffusion tensor imaging (DTI) was used to measure white matter signals in selected brain regions linked to motor circuits. Relevant DTI data of seven catatonic schizophrenia patients were compared to those of seven non-catatonic schizophrenia patients, matched for sex, age, and education level. RESULTS: Significantly elevated fractional anisotropy values were found in the splenium of the corpus callosum, the right peduncle of the cerebellum, and the right internal capsule of the schizophrenia patients with catatonia compared to those without catatonia. This finding showed altered diffusivity in selected motor-related brain areas. CONCLUSIONS: Catatonic schizophrenia is associated with dysregulation of the connectivity in specific motoric brain regions and corresponding circuits. Future DTI studies are needed to address the neural correlates of motor abnormalities in schizophrenia-related catatonia during the acute and remitted state of the illness to identify the specific pathophysiology of this disorder.

Deep Brain Stimulation of the Nucleus Accumbens, Ventral Striatum, or Internal Capsule Targets for Medication-Resistant Obsessive-Compulsive Disorder: A Multicenter Study.

BACKGROUND: Deep brain stimulation of the nucleus accumbens, ventral striatum, or internal capsule region has shown a 45%-60% response rate in adults with severe treatment-refractory obsessive-compulsive disorder, regardless of which target is used. We sought to improve the effectiveness of deep brain stimulation by placing the electrode along a trajectory including these 3 targets, enabling a change of stimulation site depending on the patient's response. METHODS: This study used the medical records of 14 patients from 4 different Spanish institutions: 7 from the Hospital Universitario La Princesa, 3 from the Hospital Universitario Central de Asturias, 2 from Hospital Universitario Fundación Jiménez Díaz, and 2 from Hospital Universitari Son Espases. All patients were operated on under the same protocol. Qualitative and quantitative data were collected. RESULTS: Of 14 patients, 11 showed significant improvement in obsessive-compulsive disorder symptoms, as evident in a reduction ≥35% in Yale-Brown Obsessive Compulsive Scale scores following stimulation relative to preoperative scores. Seven patients responded to stimulation at the nucleus accumbens (the first area we set for stimulation), whereas 4 patients needed to have the active contact switched to the internal capsule to benefit from stimulation. CONCLUSIONS: Deep brain stimulation of the nucleus accumbens, internal capsule, and ventral striatum significantly benefited our cohort of patients with medication-resistant obsessive-compulsive disorder. Electrode insertion through the 3 main targets might confer additional therapeutic efficacy.

Acute motor deficit and subsequent remyelination-associated recovery following internal capsule demyelination in mice.

Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system (CNS), characterized by accumulated motor disability. However, whether remyelination promotes motor recovery following demyelinating injury remains unclear. Damage to the internal capsule (IC) is known to result in motor impairment in multiple sclerosis and stroke. Here, we induced focal IC demyelination in mice by lysophosphatidylcholine (LPC) injection, and examined its effect on motor behavior. We also compared the effect of LPC-induced IC damage to that produced by endothelin-1 (ET1), a potent vasoconstrictor used in experimental stroke lesions. We found that LPC or ET1 injections induced asymmetric motor deficit at 7 days post-lesion (dpl), and that both lesion types displayed increased microglia/macrophage density, myelin loss, and axonal dystrophy. The motor deficit and lesion pathology remained in ET1-injected mice at 28 dpl. In contrast, LPC-injected mice regained motor function by 28 dpl, with corresponding reduction in activated microglia/macrophage density, and recovery of myelin staining and axonal integrity in lesions. These results suggest that LPC-induced IC demyelination results in acute motor deficit and subsequent recovery through remyelination, and may be used to complement future drug screens to identify drugs for promoting remyelination.

A unified connectomic target for deep brain stimulation in obsessive-compulsive disorder.

Multiple surgical targets for treating obsessive-compulsive disorder with deep brain stimulation (DBS) have been proposed. However, different targets may modulate the same neural network responsible for clinical improvement. We analyzed data from four cohorts of patients (N = 50) that underwent DBS to the anterior limb of the internal capsule (ALIC), the nucleus accumbens or the subthalamic nucleus (STN). The same fiber bundle was associated with optimal clinical response in cohorts targeting either structure. This bundle connected frontal regions to the STN. When informing the tract target based on the first cohort, clinical improvements in the second could be significantly predicted, and vice versa. To further confirm results, clinical improvements in eight patients from a third center and six patients from a fourth center were significantly predicted based on their stimulation overlap with this tract. Our results show that connectivity-derived models may inform clinical improvements across DBS targets, surgeons and centers. The identified tract target is openly available in atlas form.

Stereotactic radiofrequency thermocoagulation application in the anterior limbs of patients' internal capsules in treating intractable tic disorders.

Purpose: To investigate the effect of applying stereotactic radiofrequency thermocoagulation in the anterior limbs of patients' internal capsules in treating intractable tic disorders.Materials and methods: Patients diagnosed with intractable tic disorders were prospectively enrolled and treated using stereotactic radiofrequency thermocoagulation in the anterior limbs of the internal capsules. Periprocedural complications, effects, and follow-up outcomes were then analyzed.Results: Fifty patients were enrolled, including 38 with Tourette syndrome and 12 with persistent refractory vocal or motor tic disorders. The radiofrequency thermocoagulation procedure was performed successfully in all patients. Five participants (10%) experienced periprocedural complications, including one having a slight hemiplegia, two developing fevers (4%), and two developing urination disorders (4%). The participants underwent a follow-up for 12 months, with excellent effects being achieved in 23 patients (46%), prominent results in 13 (26%), good results in 10 (20%), and invalid results in 4 (8%), reaching an efficacy rate of 92% (46/50). Thirty-six patients experienced excellent and prominent effects, with no additional management after the radiofrequency ablation being needed, achieving a success rate of 72%. After radiofrequency thermocoagulation, the Yale Global Tic Severity Scale (YGTSS) scores were significantly reduced (p < .01) when compared with those before the procedure. Following this procedure, participants' serum dopamine levels (SDA) significantly decreased (p < .05), while their serotonin levels were significantly elevated (p < .05) when compared to the measurements taken before the procedure.Conclusion: Stereotactic radiofrequency thermocoagulation applied to the anterior limbs of patients' internal capsules may be effective for treating intractable tic disorders, without risk of serious complications.

The anterior limb of the internal capsule: Anatomy, function, and dysfunction.

The last two decades have seen a re-emergence of neurosurgery for severe, refractory psychiatric diseases, largely due to the advent of more precise and safe operative techniques. Nevertheless, the optimal targets for these surgeries remain a matter of debate, and are often grandfathered from experiences in the late 20th century. To better explore the rationale for one target in particular - the anterior limb of the internal capsule (ALIC) - we comprehensively reviewed all available literature on its role in the pathophysiology and treatment of mental illness. We first provide an overview of its functional anatomy, followed by a discussion on its role in several prevalent psychiatric diseases. Given its structural integration into the limbic system and involvement in a number of cognitive and emotional processes, the ALIC is a robust target for surgical treatment of refractory psychiatric diseases. The advent of novel neuroimaging techniques, coupled with image-guided therapeutics and neuromodulatory treatments, will continue to enable study on the ALIC in mental illness.

Enhanced positive functional connectivity strength in left-sided chronic subcortical stroke.

Patients with stroke often exhibit evidence of abnormal functional connectivity (FC). However, whether and how anatomical distance affects FC at rest remains unclear in patients with chronic subcortical stroke. Eighty-six patients with chronic (more than six months post-onset) subcortical stroke (44 left-sided patients and 42 right-sided patients) with different degrees of functional recovery, and 75 matched healthy controls underwent resting-state functional magnetic resonance imaging scanning. Positive functional connectivity strength (FCS) was computed for each voxel in the brain using a data-driven whole-brain resting state FCS method, which was further divided into short- and long-range FCS. Compared with healthy controls, patients with left-sided infarctions exhibited stronger global- and long-range FCS in the left sensorimotor cortex (SMC), and no significant intergroup difference was found for short-range FCS. No significant differences were found between the patients with right-sided infarctions and healthy controls for global, long- and short-range FCS. These findings suggested that the positive FCS alteration was connection-distance dependent within patients with left-sided chronic subcortical stroke. Also, a positive correlation was found between the FCS in the left SMC and the accuracy of the Flanker test, reflecting a compensatory FCS alteration for altered attention and executive function abilities exhibited by those with left-sided stroke.

Efficacy of Deep Brain Stimulation of the Ventral Anterior Limb of the Internal Capsule for Refractory Obsessive-Compulsive Disorder: A Clinical Cohort of 70 Patients.

OBJECTIVE: Deep brain stimulation (DBS) is an effective treatment option for patients with refractory obsessive-compulsive disorder (OCD). However, clinical experience with DBS for OCD remains limited. The authors examined the tolerability and effectiveness of DBS in an open study of patients with refractory OCD. METHODS: Seventy consecutive patients, including 16 patients from a previous trial, received bilateral DBS of the ventral anterior limb of the internal capsule (vALIC) between April 2005 and October 2017 and were followed for 12 months. Primary effectiveness was assessed by the change in scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) from baseline until the 12-month follow-up. Response was defined by a ≥35% decrease in Y-BOCS score, partial response was defined by a 25%-34% decrease, and nonresponse was defined by a <25% decrease. Secondary effectiveness measures were the Hamilton Anxiety Rating Scale (HAM-A) and the Hamilton Depression Rating Scale (HAM-D). RESULTS: Y-BOCS, HAM-A, and HAM-D scores all decreased significantly during the first 12 months of DBS. Twelve months of DBS resulted in a mean Y-BOCS score decrease of 13.5 points (SD=9.4) (40% reduction; effect size=1.5). HAM-A scores decreased by 13.4 points (SD=9.7) (55%; effect size=1.4), and HAM-D scores decreased by 11.2 points (SD=8.8) (54%; effect size=1.3). At the 12-month follow-up, 36 of the 70 patients were categorized as responders (52%), 12 patients as partial responders (17%), and 22 patients as nonresponders (31%). Adverse events included transient symptoms of hypomania, agitation, impulsivity, and sleeping disorders. CONCLUSIONS: These results confirm the effectiveness and safety of DBS of the vALIC for patients with treatment-refractory OCD in a regular clinical setting.

Diffusional plasticity induced by electroacupuncture intervention in rat model of peripheral nerve injury.

Electroacupuncture (EA) is an adjuvant therapy for peripheral nerve injury (PNI). Both peripheral and central alterations contribute to the rehabilitation process. We employed diffusion tensor imaging (DTI) to investigate the diffusion plasticity of afferent and efferent pathways caused by EA in model of peripheral nerve injury and reparation. Twenty-four rats were divided into three groups: normal group, model group and intervention group. Rats of the model group and the intervention group underwent sciatic nerve transection and anastomosis. EA intervention was performed on the intervention group at ST-36 and GB-30 for three months. Gait assessment and DTI were conducted at days post-operative (DPO) 30, 60 and 90. We selected corticospinal tract, spinothalamic tract and internal capsule as regions of interest and analyzed diffusion metrics including fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD). FA values and RD values displayed significant differences or obvious tendency while AD values maintained a stable level. RD values displayed better indicative performance than FA in internal capsule. The intervention group presented significant correlation between RD values and Regularity Index (RI) during the intervention period. The effect of EA on peripheral nerve injury repairing rats appeared to be accelerated recovery process of sensory and motor neural pathway. We proposed that RD was a potential in vivo indicator for structural plasticity caused by EA and PNI.

Targeted Infarction of the Internal Capsule in the Rat Using Microstimulation Guidance.

Background and Purpose- Lacunar strokes are subcortical infarcts with small size and high disability rates, largely due to injury of the corticospinal tract in the internal capsule (IC). Current rodent models of lacunar infarcts are created based on stereotactic coordinates. We tested the hypothesis that better understanding of the somatotopy of the IC and guiding the lesion with electrical stimulation would allow a more accurate lesion to the forelimb axons of the IC. Methods- We performed electrophysiological motor mapping and viral tracing to define the somatotopy of the IC of Sprague Dawley rats. For the lesion, we used an optrode, which contains an electrode to localize forelimb responses and an optical fiber to deliver light. The infarct was induced when light activated the photothrombotic agent Rose Bengal, which was administered systemically. Results- We found largely a separate distribution of the forelimb and hindlimb axons in the IC, both by microstimulation mapping and tract tracing. Microstimulation-guided IC lesions ablated the forelimb axons of the IC in rats and caused lasting forelimb impairments while largely preserving the hindlimb axons of the IC and surrounding gray matter. Conclusions- Stimulation guidance enabled selective and reproducible infarcts of the forelimb axons of the IC in rats. Visual Overview- An online visual overview is available for this article.

Which brain lesions produce spasticity? An observational study on 45 stroke patients.

Spasticity is an important barrier that can hinder the restoration of function in stroke patients. Although several studies have attempted to elucidate the relationship between brain lesions and spasticity, the effects of specific brain lesions on the development of spasticity remain unclear. Thus, the present study investigated the effects of stroke lesions on spasticity in stroke patients. The present retrospective longitudinal observational study assessed 45 stroke patients using the modified Ashworth Scale to measure muscle spasticity. Each patient was assessed four times: initially (within 2 weeks of stroke) and at 1, 3, and 6 months after the onset of stroke. Brain lesions were analyzed using voxel-based lesion symptom mapping (VLSM) with magnetic resonance imaging images. Spasticity developed to a certain degree within 3 months in most stroke patients with spasticity. The VLSM method with non-parametric mapping revealed that lesions in the superior corona radiata, posterior limb of the internal capsule, posterior corona radiata, thalamus, putamen, premotor cortex, and insula were associated with the development of upper-limb spasticity. Additionally, lesions of the superior corona radiata, posterior limb of the internal capsule, caudate nucleus, posterior corona radiata, thalamus, putamen, and external capsule were associated with the development of lower-limb spasticity. The present study identified several brain lesions that contributed to post-stroke spasticity. Specifically, the involvement of white matter tracts and the striatum influenced the development of spasticity in the upper and lower limbs of stroke patients. These results may be useful for planning rehabilitation strategies and for understanding the pathophysiology of spasticity in stroke patients.

Individual white matter bundle trajectories are associated with deep brain stimulation response in obsessive-compulsive disorder.

BACKGROUND: The ventral anterior limb of the internal capsule (vALIC) is a target for deep brain stimulation (DBS) in obsessive-compulsive disorder (OCD). Conventional surgical planning is based on anatomical landmarks. OBJECTIVE/HYPOTHESIS: We hypothesized that treatment response depends on the location of the active DBS contacts with respect to individual white matter bundle trajectories. This study thus aimed to elucidate whether vALIC DBS can benefit from bundle-specific targeting. METHODS: We performed tractography analysis of two fiber bundles, the anterior thalamic radiation (ATR) and the supero-lateral branch of the medial forebrain bundle (MFB), using diffusion-weighted magnetic resonance imaging (DWI) data. Twelve patients (10 females) who had received bilateral vALIC DBS for at least 12 months were included. We related the change in OCD symptom severity on the Yale-Brown obsessive-compulsive scale (Y-BOCS) between baseline and one-year follow-up with the distances from the active contacts to the ATR and MFB. We further analyzed the relation between treatment response and stimulation sites in standard anatomical space. RESULTS: We found that active stimulation of the vALIC closer to the MFB than the ATR was associated with better treatment outcome (p = 0.04; r2 = 0.34). In standard space, stimulation sites were largely overlapping between treatment (non)responders, suggesting response is independent of the anatomically defined electrode position. CONCLUSION: These findings suggest that vALIC DBS for OCD may benefit from MFB-specific implantation and highlight the importance of corticolimbic connections in OCD response to DBS. Prospective investigation is necessary to validate the clinical use of MFB targeting.

The dynamics of revascularization after white matter infarction monitored in Flt1-tdsRed and Flk1-GFP mice.

Subcortical white matter infarction causes ischemic demyelination and loss of brain functions, as the result of disturbances of the blood flow. Although angiogenesis is one of the recovery processes after cerebral infarction, the dynamics of revascularization after white matter infarction still remains unclear. We induced white matter infarction in the internal capsule of Flk1-GFP::Flt1-tdsRed double transgenic mice by injection of endothelin-1 (ET-1), a vasoconstrictor peptide, together with N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, and followed the changes in Flk1 and Flt1 expression in the vascular system in the infarct area. Reduction of Flt1-tdsRed-positive blood vessels 1 day after the injection and increase of Flk1-GFP-strongly-positive blood vessels 3 days after the injection were apparent. PDGFRß-strongly-positive (PDGFRß+) cells appeared in the infarct area 3 days after the injection and increased their number thereafter. Three days after the injection, most of these cells were in close contact with Flk1-GFP-positive endothelial cells, indicating these cells are bona fide pericytes. Seven days after the injection, the number of PDGFRß+ cells increased dramatically, and the vast majority of these cells were not in close contact with Flk1-GFP-positive endothelial cells. Taken together, our results suggest revascularization begins early after the ischemic insult, and the emerging pericytes first ensheath blood vessels and then produce fibroblast-like cells not directly associated with blood vessels.

Brain mapping of motor and functional recovery after supratentorial stroke.

OBJECTIVE: The present study aimed to identify the brain regions involved in upper and lower limb motor and functional recovery after stroke. METHODS: Twenty-five patients (mean age 73.4 years; average duration from stroke onset 50.1 months) were examined. Fractional anisotropy (FA) mapping using diffusion tensor imaging, and clinical measures, including the Fugl-Meyer motor assessment of upper and lower limbs, the Modified Barthel Index (MBI), and Functional Ambulation Category, were used for examinations. Linear regression analyses were carried out with the FA map as a dependent variable, each clinical measure as an independent variable, and patient age as a covariate. RESULTS: FA in the internal capsule of the posterior limb of the lesioned hemisphere was significantly associated with Fugl-Meyer motor assessment scores for the upper limbs, whereas FAs in the internal capsule of the posterior limb of the lesioned hemisphere, the posterior corpus callosum of the lesioned hemisphere, and the middle cerebellar peduncle of the contralateral hemisphere were associated with Fugl-Meyer motor assessment scores for the lower limb. FA in brain regions with bilateral connection fibers was commonly associated with the score on the Korean version of the MBI and participants' functional ambulation. Furthermore, the FA in the corticospinal tract in the contralesional hemisphere was also associated with the score on the Korean version of the MBI (corrected P<0.05). CONCLUSION: Motor and functional recovery of upper and lower limbs involves different brain regions. This finding is of particular relevance for treatment and recovery in stroke.

Comparison of probabilistic tractography and tract-based spatial statistics for assessing optic radiation damage in patients with autoimmune inflammatory disorders of the central nervous system.

Background: Diffusion Tensor Imaging (DTI) can evaluate microstructural tissue damage in the optic radiation (OR) of patients with clinically isolated syndrome (CIS), early relapsing-remitting multiple sclerosis and neuromyelitis optica spectrum disorders (NMOSD). Different post-processing techniques, e.g. tract-based spatial statistics (TBSS) and probabilistic tractography, exist to quantify this damage. Objective: To evaluate the capacity of TBSS-based atlas region-of-interest (ROI) combination with 1) posterior thalamic radiation ROIs from the Johns Hopkins University atlas (JHU-TBSS), 2) Juelich Probabilistic ROIs (JUEL-TBSS) and tractography methods using 3) ConTrack (CON-PROB) and 4) constrained spherical deconvolution tractography (CSD-PROB) to detect OR damage in patients with a) NMOSD with prior ON (NMOSD-ON), b) CIS and early RRMS patients with ON (CIS/RRMS-ON) and c) CIS and early RRMS patients without prior ON (CIS/RRMS-NON) against healthy controls (HCs). Methods: Twenty-three NMOSD-ON, 18 CIS/RRMS-ON, 21 CIS/RRMS-NON, and 26 HCs underwent 3 T MRI. DTI data analysis was carried out using JUEL-TBSS, JHU-TBSS, CON-PROB and CSD-PROB. Optical coherence tomography (OCT) and visual acuity testing was performed in the majority of patients and HCs. Results: Absolute OR fractional anisotropy (FA) values differed between all methods but showed good correlation and agreement in Bland-Altman analysis. OR FA values between NMOSD and HC differed throughout the methodologies (p-values ranging from p < 0.0001 to 0.0043). ROC-analysis and effect size estimation revealed higher AUCs and R2 for CSD-PROB (AUC = 0.812; R2 = 0.282) and JHU-TBSS (AUC = 0.756; R2 = 0.262), compared to CON-PROB (AUC = 0.742; R2 = 0.179) and JUEL-TBSS (AUC = 0.719; R2 = 0.161). Differences between CIS/RRMS-NON and HC were only observable in CSD-PROB (AUC = 0.796; R2 = 0.094). No significant differences between CIS/RRMS-ON and HC were detected by any of the methods. Conclusions: All DTI post-processing techniques facilitated the detection of OR damage in patient groups with severe microstructural OR degradation. The comparison of distinct disease groups by use of different methods may lead to different - either false-positive or false-negative - results. Since different DTI post-processing approaches seem to provide complementary information on OR damage, application of distinct methods may depend on the relevant research question.

Impaired Callosal Motor Fiber Integrity and Upper Extremity Motor Impairment Are Associated With Stroke Lesion Location.

BACKGROUND: Damage to the callosal motor fibers (CMFs) may affect motor recovery in patients with stroke. However, whether the severity of CMF impairment varies with lesion locations remains unclear. OBJECTIVE: To investigate (1) whether CMF impairment occurs after stroke and whether the impairment varies with lesion locations and (2) the associations of CMF impairment and upper extremity (UE) motor impairment. METHODS: Twenty-nine patients with lesions involving the corticospinal tract (CST) were categorized into 2 groups: lesions involving the CMFs (CMF group, n = 15), and lesions not involving the CMFs (non-CMF group, n = 14). Thirteen healthy adults served as the control group. Tract integrity, assessed by the mean generalized fractional anisotropy (mGFA) using diffusion spectrum imaging, of the CMFs and the CST above the internal capsule (CSTABOVE) of the ipsilesional hemisphere were compared. RESULTS: After accounting for the effect of lesion load on the CST, the CMF group exhibited a significantly lower mGFA of the CMFs than did the control and non-CMF groups (post hoc P = .005 and .001, respectively). No significant difference was observed between the non-CMF and control groups (post hoc P = .999). The CST and CMF impairment accounted for 56% of the variance of UE motor impairment in the CMF group ( P = .007), whereas no significant association was observed in the non-CMF group ( P = .570). CONCLUSIONS: CMF impairment after stroke depends on lesion locations and CMF integrity has an incremental contribution to the severity of UE motor impairment in the CMF group.

Oscillatory local field potentials of the nucleus accumbens and the anterior limb of the internal capsule in heroin addicts.

OBJECTIVES: The nucleus accumbens (NAc) is known to regulate the motivation and underlie addictive behaviors, and the anterior limb of the internal capsule (ALIC) is involved in several psychiatric disorders. Our study aimed to explore the functions of NAc and ALIC electrophysiologically. METHODS: The local field potentials (LFPs) of the NAc and ALIC were recorded from 7 heroin addicts treated with deep brain stimulation. Correlation analysis was made between LFP powers in various frequency bands and the subjects' neuropsychological test scores; coherence was calculated for the LFPs in NAc and ALIC. RESULTS: Both the NAc and ALIC exhibited prominent theta and alpha frequency band activity in the LFP power spectra. Additionally, a distinct beta band peak was detected in the power spectra of ALIC LFPs, which may represent the activity of striatal bridge cells. There was a significant negative correlation between the power of the theta frequency band of ALIC LFPs and visual analogue scale (VAS) scores indicative of cravings (Spearman's ρ = -0.758, P = 0.002), and a significant positive correlation was found between the power of the alpha frequency band of NAc LFPs and subjects' scores on the Hamilton depression inventory (ρ = 0.727, P = 0.005). LFPs of the NAc and ALIC exhibited higher coherence values in the theta and alpha frequency bands. CONCLUSIONS: The results suggest that theta power in the ALIC/dorsal striatum and alpha power in the NAc may be associated with drug cravings and depressive symptoms, respectively, in heroin addicts. For these subjects, the neural activities in the dorsal and ventral striatum were mainly coordinated within the low-frequency band. SIGNIFICANCE: The study illustrates the neurophysiologic characteristics of heroin addiction and its comorbidities, providing a potential theoretical basis for optimizing deep brain stimulation (DBS) therapy.

Chronic Intermittent Ethanol Exposure Modulation of Glutamatergic Neurotransmission in Rat Lateral/Basolateral Amygdala is Duration-, Input-, and Sex-Dependent.

The basolateral amygdala (BLA) controls numerous behaviors, like anxiety and reward seeking, via the activity of glutamatergic principal neurons. These BLA neurons receive excitatory inputs primarily via two major anatomical pathways - the external capsule (EC), which contains afferents from lateral cortical structures, and the stria terminalis (ST), containing synapses from more midline brain structures. Chronic intermittent ethanol (CIE) exposure/withdrawal produces distinct alterations in these pathways. Specifically, 10 days of CIE (via vapor inhalation) increases presynaptic function at ST synapses and postsynaptic function at EC synapses. Given that 10-day CIE/withdrawal also increases anxiety-like behavior, we sought to examine the development of these alterations at these inputs using an exposure time-course in both male and female rats. Specifically, using 3, 7, and 10 days CIE exposure, we found that all three durations increase anxiety-like behavior in the elevated plus maze. At BLA synapses, increased presynaptic function at ST inputs required shorter exposure durations relative to post-synaptic alterations at EC inputs in both sexes. But, synaptic alterations in females required longer ethanol exposures compared to males. These data suggest that presynaptic alteration at ST-BLA afferents is an early neuroadaptation during repeated ethanol exposures. And, the similar patterns of presynaptic-then-postsynaptic facilitation across the sexes suggest the former may be required for the latter. These cooperative interactions may contribute to the increased anxiety-like behavior that is observed following CIE-induced withdrawal and may provide novel therapeutic targets to reverse withdrawal-induced anxiety.

Longitudinal development of thalamic and internal capsule microstructure in autism spectrum disorder.

The thalamus is a key sensorimotor relay area that is implicated in autism spectrum disorder (ASD). However, it is unknown how the thalamus and white-matter structures that contain thalamo-cortical fiber connections (e.g., the internal capsule) develop from childhood into adulthood and whether this microstructure relates to basic motor challenges in ASD. We used diffusion weighted imaging in a cohort-sequential design to assess longitudinal development of the thalamus, and posterior- and anterior-limbs of the internal capsule (PLIC and ALIC, respectively) in 89 males with ASD and 56 males with typical development (3-41 years; all verbal). Our results showed that the group with ASD exhibited different developmental trajectories of microstructure in all regions, demonstrating childhood group differences that appeared to approach and, in some cases, surpass the typically developing group in adolescence and adulthood. The PLIC (but not ALIC nor thalamus) mediated the relation between age and finger-tapping speed in both groups. Yet, the gap in finger-tapping speed appeared to widen at the same time that the between-group gap in the PLIC appeared to narrow. Overall, these results suggest that childhood group differences in microstructure of the thalamus and PLIC become less robust in adolescence and adulthood. Further, finger-tapping speed appears to be mediated by the PLIC in both groups, but group differences in motor speed that widen during adolescence and adulthood suggest that factors beyond the microstructure of the thalamus and internal capsule may contribute to atypical motor profiles in ASD. Autism Res 2018, 11: 450-462. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Microstructure of the thalamus, a key sensory and motor brain area, appears to develop differently in individuals with autism spectrum disorder (ASD). Microstructure is important because it informs us of the density and organization of different brain tissues. During childhood, thalamic microstructure was distinct in the ASD group compared to the typically developing group. However, these group differences appeared to narrow with age, suggesting that the thalamus continues to dynamically change in ASD into adulthood.