Pain perception

Pain expectations are formed by learning the association between specific circumstances and the occurrence of pain. These expectations are known to influence pain perception. Whether this learning is statistically optimal remains debated. If it is, the learning process of the participant should reflect their perception of the precision of each observation (stochasticity) and of the instability of the environment (volatility).Further, it is unclear whether inter-individual differences observed in experimental pain learning studies are due to temporary states or intrinsic traits.To probe these q

Impaired cognition and pain after surgery contribute to prolonged hospital stays and increased mortality rates. Thus, the development of preemptive algorithms for reducing their impact should be prioritized. The main objectives of the present study were to evaluate the efficiency of using virtual reality (VR) to treat postoperative cognitive decline and pain perception. The study was a prospective, monocentric, clinical study that included 51 patients who have undergone major abdominal surgery. The patients were divided into two groups: Control (n = 25) and VR (n = 26). The VR sessions consist

…be often accompanied by suppressing pain perception via promoting consistent burst firing of dopamine neurons. Besides, sensitive and advanced research techniques led to the recognition of the mesohippocampal dopaminergic terminals, particularly in the two hippocampal regions, CA1 and dentate gyrus (DG). Previous studies have shown that dopamine receptors within these two hippocampal regions play a critical role in antinociceptive responses induced by forced swim stress (FSS) in the presence of inflammatory pain. S

The population coding account of pain proposes that a distributed network of neural activity across both nociceptive and non-nociceptive domains drives our experience of thermosensation and pain (Coghill, 2020; Fardo et al., 2020). Recent, pioneering work in mice shows that distinct neuronal population codes for cold and warm exist in the posterior insula cortex (Vestergaard et al., 2023). In this study we used fMRI to model the pattern of response associated with innocuous and noxious thermal stimuli, to determine whether similar population receptive fields (PRFs) for temperature and pain exi

…authors argued that, in the context of pain perception, fMRI was sensitive to small differences in applied noxious stimuli within an individual, but failed at predicting inter-individual differences. Here, we test in six studies whether this absent predictive power can be restored by accounting for inter-individual variance and the use of clearly distinguishable experim

Research has shown that individuals with Down syndrome experience altered pain sensitivity, with varying results depending on the type of nociceptive stimulus. GRIK1, a gene coding for the GluK1 subunit of kainate receptors is triplicated in Down syndrome. This subunit is heavily expressed in Dorsal Root Ganglion neurons and has been implicated in modulating pain perception. To investigate this further, we have conducted experiments in the Ts2Cje mouse model of Down syndrome, comparing them to mice lacking Grik1. The results suggest that altered pain perception in Down syndrome is dependent on

Pain expectation is known to influence pain perception, but the underlying neuronal mechanisms remain unclear. While the motor role of the corticospinal tract is well characterized, only recently was it established that the corticospinal neurons originating from the primary somatosensory cortex (S1-CSNs) specifically contact the sensory region of the spinal cord, providing top-down regulation of sensations including pain. S1-CSNs neurons are therefore ideally positioned to modulate spinal nociception based on sensory representations and expectations. To test whether S1-CSNs activity is modulat

Pain perception is a warning signal enabling animals to preserve their body integrity. When pain persists over time, the brain needs to learn to predict its temporal evolution in order to minimize harm. Whereas several studies have already shown the effects of experience and expectations on responses to isolated nociceptive stimuli using axiomatic approaches, it remains largely unknown how individuals can learn to predict a stream of nociceptive events and how these processes are implemented in the brain. To clarify these aspects, we exposed healthy human participants (n = 31) to probabilistic

The placebo and nocebo effects highlight the importance of expectations in modulating pain perception. Yet, we don't need an external source of information to form expectations about pain. The brain can learn to predict pain in a more fundamental way, simply by experiencing fluctuating, non-random streams of noxious inputs, and extracting their temporal regularities. This process is called statistical learning. Here we address two key open questions: (1) does statistical learning modulate pain perception? and (2) is it affected in people with chronic musculoskeletal pain? In a first experiment

The ability to experience pain is old in evolutionary terms. It is an experience shared across species. Acute pain is the body’s alarm system, and as such it is a good thing. Pain that persists beyond normal tissue healing time (3-4 months) is defined as chronic – it is the system gone wrong and it is not a good thing. Chronic pain has recently been classified as both a symptom and disease in its own right. It is one of the largest medical health problems worldwide with one in five adults diagnosed with the condition. The brain is key to the experience of pain and pain relief. This is the plac