scholarly journals Recruitment and disruption of value encoding during alcohol seeking

2019 ◽  
Author(s):  
David Ottenheimer ◽  
Karen Wang ◽  
Alexandria Haimbaugh ◽  
Patricia H. Janak ◽  
Jocelyn M. Richard

AbstractA critical area of inquiry in the neurobiology of alcohol abuse is the neural mechanisms by which cues gain the ability to elicit alcohol use. We previously showed that cue-evoked activity in rat ventral pallidum (VP) robustly encodes the value of cues trained under both Pavlovian and instrumental contingencies, despite a stronger relationship between cue-evoked responses and behavioral latency after instrumental training. Here, we assessed VP neural representations of cue value in rats trained with a Pavlovian conditioned stimulus (CS+) that predicted alcohol delivery, and in rats trained with an instrumental discriminative stimulus (DS) that predicted alcohol availability if the rat entered the reward port during the cue. We also examined the impact of alcohol exposure itself on the integrity of this type of signaling in rats trained with sucrose. Decoding of cue value based on VP firing was blunted for an alcohol CS+ versus an alcohol DS, as well as in comparison to a sucrose DS or CS+. Further, homecage alcohol exposure had opposing effects on VP encoding of cue value for a sucrose DS versus a sucrose CS+, enhancing decoding accuracy for the DS and reducing decoding accuracy for the CS+. These findings suggest that problem alcohol seeking may result from biased engagement of specific reward-related processes via changes in VP signaling.

2019 ◽  
Vol 286 (1906) ◽  
pp. 20191220 ◽  
Author(s):  
Victoria L. Pike ◽  
Katrina A. Lythgoe ◽  
Kayla C. King

Climate change and anthropogenic activity are currently driving large changes in nutritional availability across ecosystems, with consequences for infectious disease. An increase in host nutrition could lead to more resources for hosts to expend on the immune system or for pathogens to exploit. In this paper, we report a meta-analysis of studies on host–pathogen systems across the tree of life, to examine the impact of host nutritional quality and quantity on pathogen virulence. We did not find broad support across studies for a one-way effect of nutrient availability on pathogen virulence. We thus discuss a hypothesis that there is a balance between the effect of host nutrition on the immune system and on pathogen resources, with the pivot point of the balance differing for vertebrate and invertebrate hosts. Our results suggest that variation in nutrition, caused by natural or anthropogenic factors, can have diverse effects on infectious disease outcomes across species.


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Kuniaki Yanagisawa ◽  
Emiko S Kashima ◽  
Yayoi Shigemune ◽  
Ryusuke Nakai ◽  
Nobuhito Abe

Abstract Death is an important reminder that our lives are finite. Although some studies have shown that thinking about one’s own death increases temporal discounting (i.e., the devaluing of future rewards), the underlying neural mechanisms are still unknown. In a functional magnetic resonance imaging experiment, we compared the neural and behavioral processes of temporal discounting across four conditions involving distinct types of future thinking (death related, negative, neutral, and positive). Replicating prior research, the behavioral evidence showed that temporal discounting increased when thinking about one’s own future death. Multivoxel pattern analysis showed that death-related future thinking was decoded in default mode regions, including the inferior parietal lobule, precuneus, and medial prefrontal cortex (MPFC). When future thinking was death related (vs. negative), increased temporal discounting was associated with a higher decoding accuracy in the precuneus and MPFC. The present findings suggest that death-related neural representations are distributed across default mode regions, and neural populations in the cortical midline structures play a crucial role in the integration of one's own death into economic decision-making.


2019 ◽  
Author(s):  
Henry Railo ◽  
Niklas Nokelainen ◽  
Saara Savolainen ◽  
Valtteri Kaasinen

AbstractObjectiveSpeech deficits are common in Parkinson’s disease, and behavioural findings suggest that the deficits may be due to impaired monitoring of self-produced speech. The neural mechanisms of speech deficits are not well understood. We examined a well-documented electrophysiological correlate of speech self-monitoring in patients with Parkinson’s disease and control participants.MethodsWe measured evoked electroencephalographic responses to self-produced and passively heard sounds (/a/ phonemes) in age-matched controls (N=18), and Parkinson’s disease patients who had minor speech impairment, but reported subjectively experiencing no speech deficits (N=17).ResultsDuring speaking, auditory evoked activity 100 ms after phonation (N1 wave) was less suppressed in Parkinson’s disease than controls when compared to the activity evoked by passively heard phonemes. This difference between the groups was driven by increased amplitudes to self-produced phonemes, and reduced amplitudes passively heard phonemes in Parkinson’s disease.ConclusionsThe finding indicates that auditory evoked activity is abnormally modulated during speech in Parkinson’s patients who do not subjectively notice speech impairment. This mechanism could play a role in producing speech deficits in as the disease progresses.


1995 ◽  
Vol 7 (3) ◽  
pp. 419-446 ◽  
Author(s):  
Ann P. Streissguth ◽  
Fred L. Bookstein ◽  
Paul D. Sampson ◽  
Helen M. Barr

AbstractThis study examined the longitudinal components of vigilance performance and attentional behaviors across the ages of 4, 7, and 14 years of life as they relate to prenatal alcohol exposure assessed by maternal self-report in midpregnancy for a cohort of 512 children. The vigilance score most salient for prenatal alcohol across this 10-year developmental period was Standard Deviation of Reaction Time (SDRT). Also salient were False Alarms (FA) on the AX task, impulsive errors reflecting difficulty in withholding a response. All 19 of the children with poorest scores on a Vigilance Latent Variable (LV) at 14 years had scored low on a similarly-defined Vigilance LV at age 7 years. Cross-lagged correlations revealed that the 7-year Vigilance LV not only predicted second-grade teacher ratings of attention a year later (r = – .38), but also predicted fourth-fifth-grade teacher ratings of attention (r = – .36). These data reveal considerable consistency across time in the impact of prenatal alcohol on child/adolescent vigilance performance and attention between 4 and 14 years of age.


2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Erik L Meijs ◽  
Pim Mostert ◽  
Heleen A Slagter ◽  
Floris P de Lange ◽  
Simon van Gaal

Abstract Subjective experience can be influenced by top-down factors, such as expectations and stimulus relevance. Recently, it has been shown that expectations can enhance the likelihood that a stimulus is consciously reported, but the neural mechanisms supporting this enhancement are still unclear. We manipulated stimulus expectations within the attentional blink (AB) paradigm using letters and combined visual psychophysics with magnetoencephalographic (MEG) recordings to investigate whether prior expectations may enhance conscious access by sharpening stimulus-specific neural representations. We further explored how stimulus-specific neural activity patterns are affected by the factors expectation, stimulus relevance and conscious report. First, we show that valid expectations about the identity of an upcoming stimulus increase the likelihood that it is consciously reported. Second, using a series of multivariate decoding analyses, we show that the identity of letters presented in and out of the AB can be reliably decoded from MEG data. Third, we show that early sensory stimulus-specific neural representations are similar for reported and missed target letters in the AB task (active report required) and an oddball task in which the letter was clearly presented but its identity was task-irrelevant. However, later sustained and stable stimulus-specific representations were uniquely observed when target letters were consciously reported (decision-dependent signal). Fourth, we show that global pre-stimulus neural activity biased perceptual decisions for a ‘seen’ response. Fifth and last, no evidence was obtained for the sharpening of sensory representations by top-down expectations. We discuss these findings in light of emerging models of perception and conscious report highlighting the role of expectations and stimulus relevance.


2020 ◽  
Vol 56 (1) ◽  
pp. 8-16
Author(s):  
Natalia A Osna ◽  
Murali Ganesan ◽  
Devanshi Seth ◽  
Todd A Wyatt ◽  
Srivatsan Kidambi ◽  
...  

Abstract Chronic and excessive alcohol abuse cause direct and indirect detrimental effects on a wide range of body organs and systems and accounts for ~4% of deaths worldwide. Many factors influence the harmful effects of alcohol. This concise review presents newer insights into the role of select second hits in influencing the progression of alcohol-induced organ damage by synergistically acting to generate a more dramatic downstream biological defect. This review specifically addresses on how a lifestyle factor of high fat intake exacerbates alcoholic liver injury and its progression. This review also provides the mechanistic insights into how increasing matrix stiffness during liver injury promotes alcohol-induced fibrogenesis. It also discusses how hepatotropic viral (HCV, HBV) infections as well as HIV (which is traditionally not known to be hepatotropic), are potentiated by alcohol exposure to promote hepatotoxicity and fibrosis progression. Finally, this review highlights the impact of reactive aldehydes generated during alcohol and cigarette smoke coexposure impair innate antimicrobial defense and increased susceptibility to infections. This review was inspired by the symposium held at the 17th Congress of the European Society for Biomedical research on Alcoholism in Lille, France entitled ‘Second hits in alcohol-related organ damage’.


2001 ◽  
Vol 7 (5) ◽  
pp. 648-649 ◽  
Author(s):  
Paul D. Connor

The primary focus of this volume is on the impact of alcohol on brain development. It is a perfect example of how research on both animals and humans can interact to produce very important findings. In the case of prenatal alcohol exposure, dialogue between animal and human researchers has proved to be very profitable for both lines of research. Initial observations by human researchers identified a syndrome of facial stigmata, physical malformations, and early behavioral disturbances that was related to maternal alcohol abuse during pregnancy. They gave this syndrome the name Fetal Alcohol Syndrome. However, human researchers were unable to state unequivocally that prenatal alcohol exposure was teratogenic to the fetus. Thus, they turned to animal researchers who were able to model Fetal Alcohol Syndrome in a variety of animals and to confirm the teratogenicity of alcohol on the developing fetus. The quarter century of studies of the damage caused by prenatal alcohol exposure is replete with such interactions between these two groups of researchers. Without the input and pioneering studies of animal researchers on the effects of prenatal alcohol exposure, human researchers would have much less understanding of the damage caused by alcohol exposure in utero or insights into possible treatment or remediation strategies for those damaged by alcohol exposure.


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