Experimental paradigms that provide reliable and quantitative measures of the neuronal correlates of subjective perception of pain are necessary prerequisites to the clinical utility of functional neuroimaging to study pain related disorders. The study was approved by the IRB at MGH. Subjects (5 M, 4 F, 28±3 yrs) received minimal noxious mechanical pressure stimuli to one shin consisting of 6 pairs of stimuli 2 seconds in duration 3 seconds apart per 4 minute scan. Pressure stimulus intensity was individualized to elicit sensory and affective ratings in the mild and moderate ranges. Thermal stimuli eliciting the same subjective ratings were used for comparison. Subjects rated stimulus intensity after each of these 8 scans (right/left shin X mild/moderate intensity X mechanical/thermal stimuli). Whole brain EPI was performed on a 1.5T Siemens MRI system. Despite comparable ratings, thermal heat pain was less effective than mechanical pressure pain at eliciting cortical activation. Mechanical stimuli produce...

Bipolar I Disorder (BP) is a serious, recurrent mood disorder that is characterized by alternating episodes of mania and depression. To begin to identify novel approaches and pathways associated with BP, we have differentiated BP and undiagnosed control...

Read science policy and advocacy news from the week of March 17, 2017

Recent work suggests that the brain represents probability distributions and performs Bayesian integration during sensorimotor learning. However, our understanding of the neural representation of this learning remains limited. To begin to address this, ...

Animals exhibit different patterns of social behavior throughout life. During early development members of many species perform different types of affiliative behavior, but after reaching sexual maturity begin performing territorial and reproductive beh...

The consequences of aging can vary dramatically between different brain regions and cell types. In the ventral midbrain, dopaminergic neurons develop physiological deficits with normal aging that likely convey susceptibility to neurodegeneration. While nearby GABAergic neurons are thought to be more resilient, decreased GABA signaling in other areas nonetheless correlates with age-related cognitive decline and the development of degenerative diseases. Here, we used two novel cell type-specific translating ribosome affinity purification models to elucidate the impact of healthy brain aging on the molecular profiles of dopamine and GABA neurons in the ventral midbrain. By analyzing differential gene expression from young adult (7-10 months) and old (21-24 months) mice, we detected commonalities in the aging process in both neuronal types, including increased inflammatory responses and upregulation of pro-survival pathways. Both cell types also showed downregulation of genes involved in synaptic connectivity ...

The ability to register data from freely moving imaging experiments to data from high resolution confocal or multi-photon imaging will begin to provide crucial links between activity dynamics and anatomical, molecular, and/or connectivity profiles of di...

Central sensitization plays a critical role in bladder pain syndrome/interstitial cystitis (BPS/IC). Electroacupuncture (EA) nerve stimulation therapy has been broadly acknowledged as an effective means of alleviating chronic pathological pain. However, it remains to be explored whether EA is effective in mitigating pain-sensitive symptoms of BPS/IC and the mechanisms involved. This study aims to investigate the analgesic effect and mechanism of EA therapy. We employed several techniques: mechanical pain threshold tests to assess pain sensitivity, urodynamic studies to evaluate bladder function, western blotting for protein analysis, immunofluorescence for visualizing, and transcriptomics. A rat cystitis model was established through a systemic intraperitoneal injection with cyclophosphamide (CYP). EA therapy was executed by stimulating the deep part of the hypochondriac point. EA treatment was observed to effectively reduce mechanical allodynia, enhance urinary function, suppress the activation of microgl...

Understanding the ability to self-evaluate decisions is an active area of research. This research has primarily focused on the neural correlates of self-evaluation during visual-tasks, and whether neural correlates before or after the primary decision contribute to self-reported confidence. This focus has been useful, yet the reliance on subjective confidence reports may confound our understanding of key every-day features of metacognitive self-evaluation: that decisions must be rapidly evaluated without explicit feedback, and unfold in a multisensory world. These considerations led us to hypothesise that an automatic domain-general metacognitive signal may be shared between sensory modalities, which we tested in the present study with multivariate decoding of electroencephalographic (EEG) data. Participants (N=21, 12 female) first performed a visual task with no request for self-evaluations of performance, prior to an auditory task that included rating decision confidence on each trial. A multivariate cla...

Illusionism is a general philosophical framework in which specific theories of consciousness can be constructed without having to invoke a magical mind essence. The advantages of illusionism are not widely recognized, perhaps because scholars tend to think only of the most extreme forms and miss the range of possibilities. The brain's internal models are never fully accurate, nothing is exactly as the brain represents it, and therefore some element of illusionism is almost certainly necessary for any working theory of consciousness or of any other property that is accessed through introspection. Here I describe the illusionist framework and propose six specific theories. One purpose of this article is to demonstrate the range of possibilities in a domain that is not yet sufficiently explored. The second purpose is to argue that even existing, popular theories, such as the integrated information theory or the global workspace theory, can be transformed and greatly strengthened by adding an illusionist layer...