Lavrov, I. A. | Search bioRxiv

bioRxiv2025

Neurophysiological Markers for the Acute Pain Model in Rats Under Urethane-induced Anesthesia

Certain neurophysiological mechanisms of pain can be investigated in anesthetized animals, and such a model is potentially useful for the development of pain treatment. Yet, the interference of pain-related neural patterns and anesthesia-related patterns should be understood. Here we studied the interplay between acute pain-induced and urethane-induced EEG activity. We analyzed the activity of the rats somatosensory cortex under urethane-induced anesthesia both before and after introducing a painful stimulus (formalin injection into the left hindlimb). Our analysis of the EEG parameters, such as amplitude, amplitude difference between the left and right hemispheres, and spectral entropy showed significant pain-related effects. The responses to painful stimuli depended on the anesthesia phase. These results are applicable to further research in animal models and to monitoring humans placed under general anesthesia.

neuroscience↗

bioRxiv2020

Segment-specific orientation of the dorsal and ventral roots for precise therapeutic targeting of human spinal cord

An understanding of spinal cord functional neuroanatomy is essential for diagnosis and treatment of multiple disorders including, chronic pain, movement disorders, and spinal cord injury. Till now, no information is available on segment-specific spinal roots orientation in humans. In this study we collected neuroanatomical measurements of the dorsal and ventral roots from C2-L5, as well as spinal cord and vertebral bone measurements from adult cadavers. Spatial orientation of dorsal and ventral roots were measured and correlated to the anatomical landmarks of the spinal cord and vertebral column. The results show less variability in rostral root angles compared to the caudal angles across all segments. Dorsal and ventral rootlets were oriented mostly perpendicular to the spinal cord at the cervical level and demonstrate more parallel orientation at the thoracic and lumbar segments. The number of rootlets was the highest in dorsal cervical and lumbar segments. Spinal cord transverse diameter and size of the dorsal columns were largest at cervical and lumbar segments. The strongest correlation was found between the length of intervertebral foramen to rostral rootlet and vertebral bone length. These results could be used to locate spinal roots and spinal cord landmarks based on bone marks on CT or X-rays. These results also provide background for future correlations between anatomy of spinal cord and spinal column structures that could improve stereotactic surgical procedures and electrode positioning for spinal cord neuromodulation. One Sentence SummaryThis is the first detailed analysis of the segment-specific dorsal and ventral spinal roots spatial orientation measured and correlated to the anatomical landmarks of the spinal cord and vertebral column for human.

neuroscience↗