Biology subjects

Ibinson, J. W.

Publications and source records attributed to Ibinson, J. W..

4 recordsLinked to original sources

bioRxiv2021

Population Imaging of Central Sensitization

Capsaicin applied locally to the skin causes central sensitization that results in allodynia, a state in which pain is elicited by innocuous stimuli. Here, we used two-photon calcium imaging of neurons in the dorsal spinal cord to visualize central sensitization across excitatory interneurons and spinal projection neurons. To distinguish among excitatory neuron subtypes, we developed CICADA, a cell profiling approach that leverages the expression of distinct Gq-coupled receptors. We then identified capsaicin-responsive and capsaicin-sensitized neuronal populations. Capsaicin-sensitized neurons showed emergent responses to low threshold input and increased receptive field sizes consistent with the psychophysical phenomenon that allodynia is observed across an extended secondary zone. Finally, we identified spinal projection neurons that showed a shift in tuning toward low threshold input. These experiments provide a population-level view of central sensitization and a framework with which to model somatosensory integration in the dorsal horn. HighlightWarwick et al. use two-photon calcium imaging coupled with pharmacological profiling to identify neuronal populations in the spinal dorsal horn that mediate capsaicin-induced central sensitization.

neuroscience↗

bioRxiv2020

Neutral auditory words immediately followed by painful electric shock show reduced next-day recollection

In this study, we investigated the effect of experimentally delivered acute pain on explicit and implicit memory. Twenty-five subjects participated in experimental sessions on consecutive days. The first session involved a categorization task intended to induce incidental memory encoding. There were two conditions, presented in randomized order, in which subjects listened to a series of words, which was repeated three times. In one condition, one-third of the word items were immediately followed by a painful electrical shock and these pain-paired items were presented unpredictably. In the other condition, all word items were not associated with pain. Response times over these repeated presentations were assessed for differences. Explicit memory was tested the following day, employing a Remember-Know assessment of word recognition, with no shocks employed. Recollection was significantly reduced for pain-paired words, as the proportion of correct Remember responses (out of total correct responses) was significantly lower. There were no significant reductions in memory for non-pain items that followed painful stimulation after a period of several seconds. Consistent with the experience of pain consuming working memory resources, we theorize that painful shocks interrupt memory encoding for the immediately preceding experimental items, due to a shift in attention away from the word item.

neuroscience↗

bioRxiv2018

Memory for non-painful auditory items is influenced by whether they are experienced in a context involving painful electrical stimulation

In this study, we sought to examine the effect of pain on memory. Subjects heard a series of words and made categorization decisions in two different contexts. One context included painful shocks administered just after presentation of some of the words; the other context involved no shocks. For the context that included painful stimulations, every other word was followed by a shock and subjects were informed to expect this pattern. Word lists were repeated three times within each context in randomized order, with different category judgments but consistent pain-word pairings. After a brief delay, recognition memory was assessed. Non-pain words from the pain context were less strongly encoded than non-pain words from the completely pain-free context. An important accompanying finding is that response times to repeated experimental items were slower for non-pain words from the pain context, compared to non-pain words from the completely pain-free context. This demonstrates that the effect of pain on memory may generalize to non-pain items experienced in the same experimental context.

neuroscience↗

bioRxiv2018

Human posterior insula to posterior cingulate functional connectivity is related to the subjective intensity of acute pain

BackgroundSeveral studies have shown that, in the context of chronic pain, alterations in functional connectivity between the insula and default mode network (DMN) are correlated with pain intensity. However, it is unknown whether a similar relationship between insula-to-DMN connectivity and pain intensity exists in the absence of chronic pain. Our aims were 1) to assess whether insula-to-DMN connectivity changes are correlated to the intensity of ongoing acute pain in healthy subjects, and 2) provide an initial assessment of the capacity of pIns-to-PCC connectivity to differentiate between painful and non-painful states. 3T BOLD functional imaging data were obtained from 13 healthy human subjects in three conditions: rest, non-painful tactile stimulation, and capsaicin-induced pain.\n\nResultsPosterior insula to posterior cingulate (pIns-to-PCC) connectivity was significantly correlated with pain intensity. Additionally, we found that discrimination between painful and non-painful states could be achieved based on pIns-to-PCC connectivity.\n\nConclusionsFunctional connectivity alterations in healthy subjects experiencing acute ongoing pain are similar to those observed in chronic pain patients, and can be used to classify pain state. This suggests that the inclusion of the pIns and PCC regions in future fcMRI-based methods to detect ongoing pain is warranted.

neuroscience↗