scholarly journals Modeling Causal Relationship Between Brain Regions Within the Drug-Cue Processing Network in Chronic Cocaine Smokers

2015 ◽  
Vol 40 (13) ◽  
pp. 2960-2968 ◽  
Author(s):  
Suchismita Ray ◽  
Margaret Haney ◽  
Catherine Hanson ◽  
Bharat Biswal ◽  
Stephen José Hanson
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Stephen J. Kohut ◽  
Dionyssios Mintzopoulos ◽  
Brian D. Kangas ◽  
Hannah Shields ◽  
Kelly Brown ◽  
...  

AbstractLong-term cocaine use is associated with a variety of neural and behavioral deficits that impact daily function. This study was conducted to examine the effects of chronic cocaine self-administration on resting-state functional connectivity of the dorsal anterior cingulate (dACC) and putamen—two brain regions involved in cognitive function and motoric behavior—identified in a whole brain analysis. Six adult male squirrel monkeys self-administered cocaine (0.32 mg/kg/inj) over 140 sessions. Six additional monkeys that had not received any drug treatment for ~1.5 years served as drug-free controls. Resting-state fMRI imaging sessions at 9.4 Tesla were conducted under isoflurane anesthesia. Functional connectivity maps were derived using seed regions placed in the left dACC or putamen. Results show that cocaine maintained robust self-administration with an average total intake of 367 mg/kg (range: 299–424 mg/kg). In the cocaine group, functional connectivity between the dACC seed and regions primarily involved in motoric behavior was weaker, whereas connectivity between the dACC seed and areas implicated in reward and cognitive processing was stronger. In the putamen seed, weaker widespread connectivity was found between the putamen and other motor regions as well as with prefrontal areas that regulate higher-order executive function; stronger connectivity was found with reward-related regions. dACC connectivity was associated with total cocaine intake. These data indicate that functional connectivity between regions involved in motor, reward, and cognitive processing differed between subjects with recent histories of cocaine self-administration and controls; in dACC, connectivity appears to be related to cumulative cocaine dosage during chronic exposure.


2018 ◽  
Vol 30 (7) ◽  
pp. 963-972 ◽  
Author(s):  
Andrew D. Engell ◽  
Na Yeon Kim ◽  
Gregory McCarthy

Perception of faces has been shown to engage a domain-specific set of brain regions, including the occipital face area (OFA) and the fusiform face area (FFA). It is commonly held that the OFA is responsible for the detection of faces in the environment, whereas the FFA is responsible for processing the identity of the face. However, an alternative model posits that the FFA is responsible for face detection and subsequently recruits the OFA to analyze the face parts in the service of identification. An essential prediction of the former model is that the OFA is not sensitive to the arrangement of internal face parts. In the current fMRI study, we test the sensitivity of the OFA and FFA to the configuration of face parts. Participants were shown faces in which the internal parts were presented in a typical configuration (two eyes above a nose above a mouth) or in an atypical configuration (the locations of individual parts were shuffled within the face outline). Perception of the atypical faces evoked a significantly larger response than typical faces in the OFA and in a wide swath of the surrounding posterior occipitotemporal cortices. Surprisingly, typical faces did not evoke a significantly larger response than atypical faces anywhere in the brain, including the FFA (although some subthreshold differences were observed). We propose that face processing in the FFA results in inhibitory sculpting of activation in the OFA, which accounts for this region's weaker response to typical than to atypical configurations.


2002 ◽  
Vol 66 (2) ◽  
pp. 443-448 ◽  
Author(s):  
Anahit V. Azaryan ◽  
Linda J. Coughlin ◽  
Beáta Búzás ◽  
Barbara J. Clock ◽  
Brian M. Cox

2020 ◽  
Author(s):  
Ju-Chi Yu ◽  
Vincenzo G. Fiore ◽  
Richard W. Briggs ◽  
Jacquelyn Braud ◽  
Katya Rubia ◽  
...  

AbstractThe anterior insular cortex (AIC) and its interconnected brain regions have been associated with both addiction and decision-making under uncertainty. However, the causal interactions in this uncertainty-encoding neurocircuitry and how these neural dynamics impact relapse remain elusive. Here, we used model-based fMRI to measure choice uncertainty in a motor decision task in 61 individuals with cocaine use disorder (CUD) and 25 healthy controls. CUD participants were assessed before discharge from a residential treatment program and followed for up to 24 weeks. We found that choice uncertainty was tracked by the AIC, dorsal anterior cingulate cortex (dACC), and ventral striatum (VS), across participants. Stronger activations in these regions measured pre-discharge predicted longer abstinence after discharge in individuals with CUD. Dynamic causal modelling revealed an AIC-to-dACC directed connectivity modulated by uncertainty in controls, but a dACC-to-AIC connectivity in CUD participants. This reversal was mostly driven by early-relapsers (<30 days). Furthermore, CUD individuals who displayed a stronger AIC-to-dACC excitatory connection during uncertainty encoding remained abstinent for longer periods. These findings reveal a critical role of an AIC-driven, uncertainty-encoding neurocircuitry in protecting against relapse and promoting abstinence.


2017 ◽  
Author(s):  
A. Z. Enkavi ◽  
B. Weber ◽  
I. Zweyer ◽  
J. Wagner ◽  
C.E. Elger ◽  
...  

AbstractConsistent decisions are intuitively desirable and theoretically important for utility maximization. Neuroeconomics has established the neurobiological substrate of value representation, but brain regions that provide input to the value-processing network is less explored. The constructed-preference tradition within behavioral decision research gives a critical role to cognitive processes that rely on associations, suggesting a role for the hippocampus in making decisions and to do so consistently. We compared the performance of 31 patients with mediotemporal lobe (MTL) epilepsy and hippocampal lesions, 30 patients with extratemporal lobe epilepsy, and 30 healthy controls on two tasks: binary choices between candy bars based on their preferences and a number-comparison control task where the larger number is chosen. MTL patients make more inconsistent choices than the other two groups for the value-based choice but not the number-comparison task. These inconsistencies increase with the volume of compromised hippocampal tissue. These results suggest a critical involvement of the MTL in preference construction and value-based choices.SignificanceOur days are full of choices that reflect our preferences. Economics lays out models of how to optimally make these decisions. Neuroeconomics has identified a cortical value-processing network whose activity correlates with constructs related to valuation and choice in economic models. However open questions remain: How are these value signals formed, and what regions might be necessary for retrieving and computing these value signals? Inspired by cognitive models calling on associative processes in value-based decisions, this paper uses unique neuropsychological data to establish the critical role of the medial temporal lobe in making consistent choices and further informs our understanding of the value-processing network.


Author(s):  
A. E. Ritchie

The cause of bluecomb disease in turkeys is unknown. Filtration of infective intestinal contents suggests a viral origin. To date, it has not been possible to isolate the etiologic agent in various cell cultures. The purpose of this work was to characterize as many virus-like entities as were recognizable in intestines of both healthy and bluecomb-infected turkeys. By a comparison of the viral populations it was hoped that some insight might be gained into the cause of this disease. Studies of turkey hemorraghic enteritis by Gross and Moore (Avian Dis. 11: 296-307, 1967) have suggested that a bacteriophage-host cell interaction may bear some causal relationship to that disease.


Author(s):  
M. C. Whitehead

A fundamental problem in taste research is to determine how gustatory signals are processed and disseminated in the mammalian central nervous system. An important first step toward understanding information processing is the identification of cell types in the nucleus of the solitary tract (NST) and their synaptic relationships with oral primary afferent terminals. Facial and glossopharyngeal (LIX) terminals in the hamster were labelled with HRP, examined with EM, and characterized as containing moderate concentrations of medium-sized round vesicles, and engaging in asymmetrical synaptic junctions. Ultrastructurally the endings resemble excitatory synapses in other brain regions.Labelled facial afferent endings in the RC subdivision synapse almost exclusively with distal dendrites and dendritic spines of NST cells. Most synaptic relationships between the facial synapses and the dendrites are simple. However, 40% of facial endings engage in complex synaptic relationships within glomeruli containing unlabelled axon endings particularly ones termed "SP" endings. SP endings are densely packed with small, pleomorphic vesicles and synapse with both the facial endings and their postsynaptic dendrites by means of nearly symmetrical junctions.


2020 ◽  
Vol 31 (2) ◽  
pp. 62-68
Author(s):  
Sara E. Holm ◽  
Alexander Schmidt ◽  
Christoph J. Ploner

Abstract. Some people, although they are perfectly healthy and happy, cannot enjoy music. These individuals have musical anhedonia, a condition which can be congenital or may occur after focal brain damage. To date, only a few cases of acquired musical anhedonia have been reported in the literature with lesions of the temporo-parietal cortex being particularly important. Even less literature exists on congenital musical anhedonia, in which impaired connectivity of temporal brain regions with the Nucleus accumbens is implicated. Nonetheless, there is no precise information on the prevalence, causes or exact localization of both congenital and acquired musical anhedonia. However, the frequent involvement of temporo-parietal brain regions in neurological disorders such as stroke suggest the possibility of a high prevalence of this disorder, which leads to a considerable reduction in the quality of life.


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