Biology subjects

Weinrich, J. A.

Publications and source records attributed to Weinrich, J. A..

5 recordsLinked to original sources

bioRxiv2026

Single-nuclear RNA sequencing reveals an ATF3-independent sensory-neuron program after surgical incision

BackgroundAcute postoperative pain is common and often treated with opioids, but which sensory-neuron changes are responsible for the peripheral drive of pain is poorly defined. Skin incision induces activating transcription factor 3 (ATF3), the canonical marker of nerve injury, in dorsal root ganglion (DRG) neurons, and ATF3 marks the neurons that remain hyperexcitable. Whether ATF3 is required for postoperative pain is unknown. MethodsAdult mice of both sexes underwent hind-paw plantar incision. Postoperative nociceptive behavior was compared between sensory-neuron-specific ATF3 conditional-knockout mice (AvilCre/+; Atf3fl/fl) and littermate controls using assays that probe distinct primary-afferent modalities (von Frey; Hargreaves; dynamic light touch) together with an operator-independent index of spontaneous injury behavior. Single-nucleus RNA sequencing of wild-type and ATF3-null DRG sensory neurons (naive and postoperative day 1) characterized the initiating injury program; transcription-factor-activity inference, RNAscope, and phospho-c-Jun immunostaining examined c-Jun; and the oral dual leucine zipper kinase (DLK) inhibitor GNE-3511, given at the time of incision, was tested behaviorally. ResultsIncision transiently induced ATF3 in a subset of DRG neurons, returning to baseline by day 14, in parallel with the two-week course of nociceptive behavior. Deleting ATF3 in sensory neurons did not change the onset or resolution of nociceptive behavior on any readout, in either sex, across mechanical, thermal, and tactile modalities. Single-nucleus profiling showed a broad surgery-responsive nociceptor program in which ATF3 was the most strongly induced gene, yet only 23% of surgery-responsive neurons expressed it. Without ATF3, the program was remodeled but not abolished, and transcription-factor-activity inference nominated c-Jun as a candidate ATF3-independent factor; incision induced c-Jun in vivo. Systemic inhibition of DLK, which activates c-Jun pathway, lowered c-Jun phosphorylation and reduced evoked nociceptive hypersensitivity. ConclusionsOur results indicate that ATF3 marks part of the injured sensory neuron but does not drive acute post-surgical nociceptive behavior, and that it is not required for the postsurgical pain behaviors across afferent modalities carried by molecularly distinct nociceptor classes. The underlying injury program is broader than ATF3 and is nominated to depend on c-Jun. Because DLK inhibition, given at the time of incision, reduced evoked hypersensitivity, we propose the DLK-JNK-c-Jun axis as a candidate perioperative non-opioid target, which will require further genetic validation.

neuroscience↗

bioRxiv2025

Photothrombotic Ischemic Thalamic Stroke in Mice Recapitulates Spontaneous Pain Features of Central Post-Stroke Pain in Humans

Central post-stroke pain (CPSP) is a highly distressing condition that develops in 50% of people who suffer a thalamic stroke, and is typically unresponsive to current clinical treatments. Hypoxic damage to the ventral posterolateral (VPL) and ventral posteromedial (VPM) sensory thalamic nuclei, in particular, precipitates CPSP. One barrier to developing treatments for CPSP is the lack of preclinical models of thalamic ischemic stroke. In this study, we present a novel mouse model of CPSP induced through targeted photothrombotic ischemia. After eliciting hypoxia in the sensory thalamus of male mice, we assessed pain behaviors over a four-week period. Stroke-affected mice exhibited a persistent spontaneous facial grimace from day four to week four post-stroke, indicative of pain. Hind-paw mechanical hypersensitivity indicative of altered nociception, characteristic of VPL and VPM hemorrhagic CPSP models, was not detected in our model. Immunofluorescence analysis revealed increased activated microglia (Iba1) and reactive astrocytes (GFAP). Iba1 fluorescence intensity in the VPL thalamus-but not the VPM thalamus-correlated with the severity of facial grimace at four weeks post-stroke. Clustering based on behavioral phenotypes identified a subpopulation of mice in which grimace pain spontaneously resolved, by four weeks post-stroke, relative to sham controls, suggesting that this model can be used to understand how stroke recovery may influence pain chronification. This model provides a valuable tool to investigate the cellular and circuit mechanisms underlying CPSP after an ischemic thalamic stroke. Significance StatementResearch into central post-stroke pain (CPSP) is hindered by the lack of preclinical models that match the clinical presentation of the condition. Although 87% of clinical strokes are ischemic, current CPSP preclinical models induce hemorrhagic strokes. To our knowledge, our mouse model is the first to induce CPSP by photothrombosis in the ventral posterolateral and posteromedial thalamus. Moreover, our study quantifies spontaneous pain, using a facial grimace score, in addition to nociception, whereas previous CPSP studies have relied exclusively on nociceptive tests. Finally, our model recapitulates some of the variability observed in clinical CPSP. We anticipate that this model will help dissect the roots of chronic pain after a thalamic stroke, and facilitate development of novel therapies for CPSP.

neuroscience↗

bioRxiv2023

Paradoxical increases in anterior cingulate cortex activity during nitrous oxide-induced analgesia reveal a signature of pain affect

The general consensus is that increases in neuronal activity in the anterior cingulate cortex (ACC) contribute to pains negative affect. Here, using in vivo imaging of neuronal calcium dynamics in mice, we report that nitrous oxide, a general anesthetic that reduces pain affect, paradoxically, increases ACC spontaneous activity. As expected, a noxious stimulus also increased ACC activity. However, as nitrous oxide increases baseline activity, the relative change in activity from pre-stimulus baseline was significantly less than the change in the absence of the general anesthetic. We suggest that this relative change in activity represents a neural signature of the affective pain experience. Furthermore, this signature of pain persists under general anesthesia induced by isoflurane, at concentrations in which the mouse is unresponsive. We suggest that this signature underlies the phenomenon of connected consciousness, in which use of the isolated forelimb technique revealed that pain percepts can persist in anesthetized patients.

neuroscience↗

bioRxiv2021

Transcription Factor Gene Pea3 Regulates Erectile Function in Mice

BackgroundMale mice with homozygous loss of function mutations of the ETS transcription factor gene Pea3 (Pea3 null) are infertile due to their inability to deposit semen plugs, however the specific deficits in male sexual behaviors that drive this phenotype are unknown. AimTo investigate the regulatory role of the Pea3 gene in organizing gross sexual behaviors and erectile functioning during active copulation. MethodsThe copulatory behavior of male mice (Pea3 null and control) with hormonally primed ovariectomized females was monitored via high-speed and high-resolution digital videography to assess for differences in female-directed social behaviors, gross sexual behaviors (mounting, thrusting), and erectile and ejaculatory function. OutcomesPea3 null male mice have dramatically reduced erectile function during sexual intercourse, however other aspects of male sexual behaviors are largely intact. ResultsPea3 null male mice exhibit greatly reduced erectile function, with 44% of males displaying no visible erections during mounting behaviors, and none achieving sustained erections. As such, Pea3 null males are incapable of intromission, and semen plug deposition, despite displaying largely normal female-directed social behaviors, mounting behaviors, and ejaculatory grasping behavior. Additionally, the coordination of the timing of thrusting trains is impaired in Pea3 null males. Clinical ImplicationsThe identification of the transcription factor Pea3 in regulating erectile function in mice may provide a useful target for understanding the genetics of male sexual dysfunction in human patients. Strengths and LimitationsHigh-speed and high-resolution videography allows for a detailed analysis of male sexual behaviors and erectile functioning in Pea3 null and control mice. How disruption of the Pea3 gene translates to erectile dysfunction is still unknown. ConclusionThe transcription factor gene Pea3 regulates the ability to achieve and maintain erections in male mice.

animal behavior and cognition↗

bioRxiv2020

Pain and itch processing by subpopulations of molecularly diverse spinal and trigeminal projection neurons

A remarkable molecular and functional heterogeneity of the primary sensory neurons and dorsal horn interneurons transmits pain- and or itch-relevant information, but the molecular signature of the projection neurons that convey the messages to the brain is unclear. Here, using retro-TRAP (translating ribosome affinity purification) and RNA-seq we reveal extensive molecular diversity of spino- and trigeminoparabrachial projection neurons, which to date are almost exclusively defined by their expression of the neurokinin 1 receptor (NK1R). Among the many genes identified, we highlight distinct subsets of Cck+, Nptx2+, Nmb+, and Crh+ expressing projection neurons. By combining in situ hybridization of retrogradely labeled neurons with Fos-based assays we also demonstrate significant functional heterogeneity, including both convergence and segregation of pain- and itch-provoking inputs onto molecularly diverse subsets of NK1R- and non-NK1R-expressing projection neurons. The current study provides the first comprehensive investigation into the molecular profiles and functional properties of projection neuron subtypes.

neuroscience↗