Biology subjects

Kaushalya, S.

Publications and source records attributed to Kaushalya, S..

3 recordsLinked to original sources

bioRxiv2024

Three-photon in vivo imaging of neurons and glia in the medial prefrontal cortex with sub-cellular resolution

The medial prefrontal cortex (mPFC) is important for higher cognitive functions, including working memory, decision making, and emotional control. In vivo recordings of neuronal activity in the mPFC have been achieved via invasive electrical and optical approaches. Here we apply low invasive three-photon in vivo imaging in the mPFC of the mouse at unprecedented depth. Specifically, we measure neuronal and astrocytic Ca2+-transient parameters in awake head-fixed mice up to a depth of 1700 {micro}m. Furthermore, we longitudinally record dendritic spine density (0.41 {+/-}0.07 {micro}m-1) deeper than 1 mm for a week. Using 1650 nm wavelength to excite red fluorescent microglia, we quantify their processes motility (58.9 {+/-}2% turnover rate) at previously unreachable depths (1100 {micro}m). We establish three-photon imaging of the mPFC enabling neuronal and glial recordings with subcellular resolution that will pave the way for novel discoveries in this brain region.

neuroscience↗

bioRxiv2023

Loss of secondary motor cortex neurons in chronic neuropathic pain

Chronic neuropathic pain is associated with structural plasticity of the brain on different spatial scales, yet, little is known on the mesoscopic scale of tissue composition. Here, we determined the cellular composition of cortical areas and structural variability of entire neurons during the development of chronic neuropathic pain using longitudinal in vivo two-photon microscopy and behavioral assessment. When monitoring cell type composition in response to spared-nerve injury in 84 cortical volumes containing {bsim}25000 cells each, we found neuronal loss in the secondary motor cortex region M2 immediately adjacent to the cingulate cortex already one week after surgery. Loss of mostly interneurons was also evident when monitoring individual M2 neurons over time. This neuronal loss was preceded by decreased spine density and loss of distal dendritic branches. In conclusion, our work delineates M2 as a novel site and neuronal loss as a so far underappreciated mechanism underlying chronic neuropathic pain states.

neuroscience↗

bioRxiv2022

Primary Somatosensory Cortex Bidirectionally Modulates Sensory Gain and Nociceptive Behavior in a Layer-Specific Manner

The primary somatosensory cortex (S1) is a hub for body sensation of both innocuous and noxious signals, yet its role in somatosensation versus pain is debated. Despite known contributions of S1 to sensory gain modulation, its causal involvement in subjective sensory experiences remains elusive. Here, in mouse S1, we reveal the involvement of cortical output neurons in layers 5 (L5) and 6 (L6) in the perception of innocuous and noxious somatosensory signals. We find that L6 activation can drive aversive hypersensitivity and spontaneous nocifensive behavior. Linking behavior to neuronal mechanisms, we find that L6 enhances thalamic somatosensory responses, and in parallel, strongly suppresses L5 neurons. Directly suppressing L5 reproduced the pronociceptive phenotype induced by L6 activation, suggesting an anti-nociceptive function for L5 output. Indeed, L5 activation reduced sensory sensitivity and reversed inflammatory allodynia. Together, these findings reveal a layer-specific and bidirectional role for S1 in modulating subjective sensory experiences.

neuroscience↗