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European Neuropsychopharmacology : the... Apr 2020Ketamine infusion therapy can produce fast-acting antidepressant effects in patients with major depressive disorder (MDD). Yet, how single and repeated ketamine...
Ketamine infusion therapy can produce fast-acting antidepressant effects in patients with major depressive disorder (MDD). Yet, how single and repeated ketamine treatment induces brain systems-level neuroplasticity underlying symptom improvement is unknown. Advanced multiband imaging (MB) pseudo-continuous arterial spin labeling (pCASL) perfusion MRI data was acquired from patients with treatment resistant depression (TRD) (N = 22, mean age=35.2 ± 9.95 SD, 27% female) at baseline, and 24 h after receiving single, and four subanesthetic (0.5 mg/kg) intravenous ketamine infusions. Changes in global and regional CBF were compared across time points, and relationships with overall mood, anhedonia and apathy were examined. Comparisons between patients at baseline and controls (N = 18, mean age=36.11 ± 14.5 SD, 57% female) established normalization of treatment effects. Results showed increased regional CBF in the cingulate and primary and higher-order visual association regions after first ketamine treatment. Baseline CBF in the fusiform, and acute changes in CBF in visual areas were related to symptom improvement after single and repeated ketamine treatment, respectively. In contrast, after serial infusion therapy, decreases in regional CBF were observed in the bilateral hippocampus and right insula with ketamine treatment. Findings demonstrate that neurophysiological changes occurring with single and repeated ketamine treatment follow both a regional and temporal pattern including sensory and limbic regions. Initial changes are observed in the posterior cingulate and precuneus and primary and higher-order visual areas, which relate to clinical responses. However, repeated exposure to ketamine, though not relating to clinical outcome, appears to engage deeper limbic structures and insula. ClinicalTrials.gov: Biomarkers of Fast Acting Therapies in Major Depression, https://clinicaltrials.gov/ct2/show/NCT02165449, NCT02165449.
Topics: Adult; Affect; Anhedonia; Apathy; Brain Mapping; Cerebrovascular Circulation; Depressive Disorder, Major; Depressive Disorder, Treatment-Resistant; Excitatory Amino Acid Antagonists; Female; Humans; Ketamine; Limbic System; Magnetic Resonance Imaging; Male; Middle Aged; Nerve Net; Neuronal Plasticity; Perfusion; Sensation
PubMed: 32061453
DOI: 10.1016/j.euroneuro.2020.01.017 -
AJNR. American Journal of Neuroradiology 1995
Review
Topics: Brain Mapping; Cerebral Cortex; Dominance, Cerebral; Emotions; Gyrus Cinguli; Hippocampus; Humans; Limbic System; Mammillary Bodies; Nerve Net; Neural Pathways; Thalamus
PubMed: 7677030
DOI: No ID Found -
Trends in Cognitive Sciences Jan 2012Psychopaths commit a disproportionate amount of violent crime, and this places a substantial economic and emotional burden on society. Elucidation of the neural... (Review)
Review
Psychopaths commit a disproportionate amount of violent crime, and this places a substantial economic and emotional burden on society. Elucidation of the neural correlates of psychopathy may lead to improved management and treatment of the condition. Although some methodological issues remain, the neuroimaging literature is generally converging on a set of brain regions and circuits that are consistently implicated in the condition: the orbitofrontal cortex, amygdala, and the anterior and posterior cingulate and adjacent (para)limbic structures. We discuss these findings in the context of extant theories of psychopathy and highlight the potential legal and policy implications of this body of work.
Topics: Amygdala; Antisocial Personality Disorder; Brain Mapping; Criminal Psychology; Humans; Limbic System; Models, Neurological; Neural Pathways; Neuroimaging; Prefrontal Cortex; Psychopathology; Violence
PubMed: 22177031
DOI: 10.1016/j.tics.2011.11.008 -
Brain, Behavior and Evolution 1995Recent studies of the limbic system of tetrapods have made data available that challenge some of the long-held tenets of forebrain evolution. Using the basic principle... (Comparative Study)
Comparative Study Review
Recent studies of the limbic system of tetrapods have made data available that challenge some of the long-held tenets of forebrain evolution. Using the basic principle of parsimony--that the best hypotheses concerning homologies are those requiring the fewest number of evolutionary changes--we have reevaluated comparisons of tetrapod limbic systems. Given the current data, the following points appear to be justified: (1) the common ancestors of reptiles and mammals had a well-developed limbic system in which the basic subdivisions and connections of the amygdalar nuclei were established; (2) the ventral part of the lateral pallium in amphibians appears to be a single structure which corresponds to at least four areas in reptiles: centromedial DVR, ventral anterior amygdala, lateral amygdala, and part of the lateral cortex; (3) the medial pallium in amphibians appears to be homologous with the dorsal and medial cortices in reptiles and with the general and hippocampal cortices in mammals: (4) the cortical targets of the main olfactory bulb in reptiles and mammals appear to be homologous, and their common ancestor probably had a corresponding olfactory pallial field; (5) the targets of the accessory olfactory bulb in amphibians, reptiles, and mammals appear to be homologous, with the exception of nucleus sphericus in reptiles, which lacks an obvious homologue in non-reptiles.
Topics: Amphibians; Amygdala; Animals; Biological Evolution; Brain Mapping; Cerebral Cortex; Limbic System; Mammals; Reptiles
PubMed: 8564465
DOI: 10.1159/000113276 -
Annals of the New York Academy of... Dec 2008The hypothalamo-pituitary-adrenocortical (HPA) axis is responsible for initiation of glucocorticoid stress responses in all vertebrate animals. Activation of the axis is... (Review)
Review
The hypothalamo-pituitary-adrenocortical (HPA) axis is responsible for initiation of glucocorticoid stress responses in all vertebrate animals. Activation of the axis is regulated by diverse afferent input to the hypothalamic paraventricular nucleus (PVN). This review discusses brain mechanisms subserving generation and inhibition of stress responses focusing on the contribution of the limbic system and highlighting recent conceptual advances regarding organization of stress response pathways in the brain. First, control of HPA axis responses to psychogenic stimuli is exerted by a complex neurocircuitry that involves oligosynaptic networks between limbic forebrain structures and the PVN. Second, individual stress-modulatory structures can have a heterogeneous impact on HPA axis responses, based on anatomical micro-organization and/or stimulus properties. Finally, HPA axis hyperactivity pursuant to chronic stress involves a substantial functional and perhaps anatomical reorganization of central stress-integrative circuits. Overall, the data suggest that individual brain regions do not merely function as monolithic activators or inhibitors of the HPA axis and that network approaches need be taken to fully understand the nature of the neuroendocrine stress response.
Topics: Amygdala; Animals; Cerebral Cortex; Glucocorticoids; Hippocampus; Humans; Hypothalamo-Hypophyseal System; Limbic System; Pituitary-Adrenal System; Stress, Physiological
PubMed: 19120092
DOI: 10.1196/annals.1410.012 -
Annals of the New York Academy of... Feb 2010In an ever-changing environment, animals must learn new behavioral strategies for the successful procurement of food, sex, and other needs. Synaptic plasticity within... (Review)
Review
In an ever-changing environment, animals must learn new behavioral strategies for the successful procurement of food, sex, and other needs. Synaptic plasticity within the mesolimbic system, a key reward circuit, affords an animal the ability to adapt and perform essential goal-directed behaviors. Ironically, drugs of abuse can also induce synaptic changes within the mesolimbic system, and such changes are hypothesized to promote deleterious drug-seeking behaviors in lieu of healthy, adaptive behaviors. In this review, we will discuss drug-induced neuroadaptations in excitatory transmission in the ventral tegmental area and the nucleus accumbens, two critical regions of the mesolimbic system, and the possible role of dopamine receptors in the development of these neuroadaptations. In particular, we will focus our discussion on recent studies showing changes in AMPA receptor function as a common molecular target of addictive drugs, and the possible behavioral consequences of such neuroadaptations.
Topics: Animals; Behavior, Animal; Dopamine; Illicit Drugs; Limbic System; Long-Term Potentiation; Long-Term Synaptic Depression; Neuronal Plasticity; Receptors, AMPA; Substance-Related Disorders
PubMed: 20201850
DOI: 10.1111/j.1749-6632.2009.05154.x -
Parkinsonism & Related Disorders Jan 2018The name functional rather than psychogenic is getting to be more widely used for terminology of this condition. It is better accepted by patients and keeps an open mind... (Review)
Review
The name functional rather than psychogenic is getting to be more widely used for terminology of this condition. It is better accepted by patients and keeps an open mind in searching for greater understanding of the pathophysiology. Advances in the pathophysiology show an overactive limbic system with connections to the motor system. Moreover, there is a disruption of the self-agency network, possibly due to a failure of feedforward signaling. There has recently been more success in treating patients. The strongest evidence is for intensive physical therapy coupled with at least some psychological support. Psychotherapy with cognitive behavioral therapy may well also be useful.
Topics: Humans; Limbic System; Movement Disorders; Psychotherapy
PubMed: 28709746
DOI: 10.1016/j.parkreldis.2017.07.002 -
Experimental Dermatology Apr 2013Perceived stress has long been known to alter the dynamic equilibrium established between the nervous, endocrine and immune system and is widely recognised to trigger or... (Review)
Review
Perceived stress has long been known to alter the dynamic equilibrium established between the nervous, endocrine and immune system and is widely recognised to trigger or enhance pruritus. However, the exact mechanism of how the major stress response systems, such as the hypothalamus-pituitary adrenal (HPA) axis and the autonomic nervous system induce or aggravate chronic itch, has not been elucidated. The limbic regions of the brain such as the prefrontal cortex and hippocampus are deeply involved in the regulation of the stress response and intersect with circuits that are responsible for memory and reward. According to the 'Polyvagal Theory', certain limbic structures that serve as a 'higher brain equivalent of the parasympathetic nervous system' play a foremost role in maintaining body homoeostasis by functioning as an active vagal brake. In addition, the limbic system has been postulated to regulate two distinct, yet related aspects of itch: (i) the sensory-discriminative aspect; and (ii) the affective-cognitive aspect. Chronic stress-induced itch is hypothesised to be caused by stress-related changes in limbic structure with subsequent rewiring of both the peripheral and central pruriceptive circuits. Herein, we review data suggesting that a dysfunctional parasympathetic nervous system associated with chronic stress may play a critical role in the regulatory control of key candidate molecules, receptors and brain structures involved in chronic itch.
Topics: Animals; Chronic Disease; Humans; Limbic System; Models, Neurological; Parasympathetic Nervous System; Pruritus; Stress, Physiological
PubMed: 23528208
DOI: 10.1111/exd.12070 -
Psychoneuroendocrinology Mar 2019We investigated if the relationship between age and regional limbic system brain structure would be moderated by diurnal cortisol output and diurnal cortisol slope....
We investigated if the relationship between age and regional limbic system brain structure would be moderated by diurnal cortisol output and diurnal cortisol slope. Participants aged 23-83 years collected seven salivary cortisol samples each day for 10 consecutive days and underwent magnetic resonance imaging. Age, sex, cortisol, and an age x cortisol interaction were tested as predictors of hippocampal and amygdalar volume and caudal and rostral anterior cingulate cortex (ACC) thickness. We found significant interactions between age and cortisol on left and right amygdalar volumes and right caudal ACC thickness. Older adults with higher cortisol output had smaller left and right amygdalar volumes than older adults with lower cortisol output and younger adults with higher cortisol output. Older and younger adults with lower cortisol output had similar amygdalar volumes. Older adults with a steeper decline in diurnal cortisol had a thicker right caudal ACC than younger adults with a similarly shaped cortisol slope. Hippocampal volume was not related to either cortisol slope or output, nor was pallidum volume which was assessed as an extra-limbic control region. Results suggest that subtle differences in cortisol output are related to differences in limbic system structure in older but not younger adults.
Topics: Adult; Age Factors; Aged; Aged, 80 and over; Amygdala; Brain; Circadian Rhythm; Female; Gyrus Cinguli; Hippocampus; Humans; Hydrocortisone; Limbic System; Magnetic Resonance Imaging; Male; Middle Aged; Saliva
PubMed: 30453123
DOI: 10.1016/j.psyneuen.2018.09.014 -
Journal of Neurosurgery Jan 2014Cingulotomy and limbic leucotomy are lesioning surgeries with demonstrated benefit for medically intractable psychiatric illnesses. They represent significant...
OBJECT
Cingulotomy and limbic leucotomy are lesioning surgeries with demonstrated benefit for medically intractable psychiatric illnesses. They represent significant refinements of the prefrontal lobotomy used from the 1930s through the 1950s. However, the associations between anatomical characterization of these lesions and outcome data are not well understood. To elucidate these procedures and associations, the authors sought to define and compare the neuroanatomy of cingulotomy and limbic leucotomy and to test a method that uses neuroanatomical data and voxel-based lesion-symptom mapping (VLSM) to reveal potential refinements to modern psychiatric neurosurgical procedures.
METHODS
T1-weighted MR images of patients who had undergone cingulotomy and limbic leucotomy were segmented and registered onto the Montreal Neurological Institute T1-weighted template brain MNI152. Using an atlas-based approach, the authors calculated, by case, the percentage of each anatomical structure affected by the lesion. Because of the infrequency of modern lesion procedures and the requirement for higher-resolution clinical imaging, the sample size was small. The pilot study correlated cingulotomy and limbic leucotomy lesion characteristics with clinical outcomes for patients with obsessive-compulsive disorder. For this study, preoperative and postoperative Yale-Brown Obsessive Compulsive Scale scores for 11 cingulotomy patients and 8 limbic leucotomy patients were obtained, and lesion masks were defined and compared anatomically by using an atlas-based method. Statistically significant voxels were additionally calculated by using VLSM techniques that correlated lesion characteristics with postoperative scores.
RESULTS
Mean lesion volumes were 13.3 ml for cingulotomy and 11.8 ml for limbic leucotomy. As expected, cingulotomy was isolated to the anterior cingulum. The subcaudate tractotomy portion of limbic leucotomy additionally affected Brodmann area 25, the medial orbitofrontal cortex, and the nucleus accumbens. Initial results indicated that the dorsolateral regions of the cingulotomy lesion and the posteroventral regions of the subcaudate tractotomy lesion were associated with improved postoperative Yale-Brown Obsessive Compulsive Scale scores.
CONCLUSIONS
Cingulotomy and limbic leucotomy are lesioning surgeries that target pathological circuits implicated in psychiatric disease. Lesion analysis and VLSM contextualize outcome data and have the potential to be useful for improving lesioning neurosurgical procedures.
Topics: Adult; Female; Gyrus Cinguli; Humans; Limbic System; Magnetic Resonance Imaging; Male; Obsessive-Compulsive Disorder; Postoperative Period; Psychosurgery; Treatment Outcome
PubMed: 24236652
DOI: 10.3171/2013.9.JNS13839