Biology subjects

Kahle, K. T.

Publications and source records attributed to Kahle, K. T..

8 recordsLinked to original sources

bioRxiv2026

An integrated multi-omic atlas of the choroid plexus highlights conserved molecular programs of epithelial function

The choroid plexus (ChP) is a specialized epithelial tissue responsible for production of cerebrospinal fluid (CSF), maintenance of the blood-CSF barrier and regulation of CSF-borne signaling factors. However, despite the ChP's central role in CSF homeostasis, conserved molecular programs of ChP epithelial function across species and conditions remain incompletely defined. In this study, we integrated eight mouse and human single-cell/nucleus RNA-seq datasets to build a multi-species ChP atlas capturing major epithelial, stromal, vascular, and immune populations. Cross-dataset differential expression identified a conserved epithelial gene program encompassing ion transport, barrier function, ciliogenesis, and secretory signaling, while prioritizing understudied genes including CLIC6 and VAT1L. Co-expression network analysis resolved conserved epithelial meta-programs, and transcription factor regulatory inference identified OTX2, MSX1, and GLIS3 among conserved regulators of epithelial gene expression. We also generated a novel Visium HD spatial transcriptomic atlas of mouse fourth-ventricle ChP to orthogonally validate epithelial modules. Lastly, cross-tissue analyses revealed substantial transcriptional overlap between ChP and retinal pigment epithelium, including shared epithelial genes and OTX2-associated regulatory relationships. Together, these findings define conserved molecular programs of ChP epithelial specialization, nominate candidate regulators for functional investigation, and provide an integrated cross-species and spatial resource for studying ChP physiology.

neuroscience↗

bioRxiv2026

Scaling of Neuronal Growth and Excitability Through Separable mTORC1 and mTORC2 Pathways

As neurons grow, they must regulate intrinsic excitability to maintain an appropriate level of spiking based on synaptic inputs. Using gene knockouts, phosphoproteomics, and electrophysiology we show PTEN regulates neuronal growth and intrinsic excitability through separable downstream mechanisms. Pten loss induces cellular hypertrophy, increased excitatory synaptic input, reduced fast afterhyperpolarization, and burst firing. Deleting the mTORC1 scaffold, Raptor, rescues overgrowth and synaptic input but fails to normalize firing, while deleting Akt or the mTORC2 scaffold, Rictor, restores firing without rescuing growth. This dissociation identifies an AKT-mTORC2 mechanism that regulates voltage-gated calcium and BK potassium channels to set spike repolarization and burst firing. In vivo, Pten knockout produces altered network synchrony, lethal seizures, and impaired object and location behavior; Raptor co-deletion display non-lethal hyperexcitability with improved object-location coupling. The biological and pathophysiological significance of these mechanisms is demonstrated by overlap of the PTEN-regulated phosphoproteome with ASD and epilepsy.

neuroscience↗

bioRxiv2026

WNK-SPAK/OSR1 signaling pathway facilitates ictal activity via reduced neuronal chloride extrusion rate

Seizures upregulate Na+-K+-2Cl- (NKCC1)-mediated Cl- influx and downregulate K+-Cl- (KCC2)-mediated Cl- efflux via the WNK-SPAK/OSR1 kinases, leading to cytoplasmic chloride ([Cl-]i) accumulation, reduced GABAergic inhibition and anticonvulsant failure. Early studies found that inhibiting WNK-kinase reduced baseline [Cl-]i (ECl) and seizures via increased KCC2 activity. However, increased KCC2 activity alone should not affect ECl whose determinants are more complex. We determined the net effects of WNK-SPAK/OSR1 pathway inhibitor WNK463 on ECl and [Cl-]i transients during spontaneous ictal-like discharges (ILDs). We found that WNK463 reduced interictal [Cl-]i but did not change baseline [Cl-]i measured in the presence of TTX. WNK463 enhanced neuronal Cl- extrusion during and after ILDs, before abolishing ILDs. Pharmacological inhibition and targeted siRNA silencing demonstrated that the anti-ictal effects of WNK463 involved both NKCC1 and KCC2. Our data support a mechanism whereby mutual NKCC1 inhibition and KCC2 activation via the WNK-SPAK/OSR1 pathway exert powerful anti-ictal effects by facilitating [Cl-]i extrusion during ILDs.

neuroscience↗

bioRxiv2026

Vessel-Resolved Mapping of Perivascular Spaces Reveals Hierarchical Neurofluid Organization In Vivo

Perivascular spaces (PVS) are central to cerebrospinal fluid (CSF)-interstitial fluid (ISF) exchange in the brain, yet their brain-wide organization and in vivo accessibility remain poorly resolved due to limited spatial resolution and contrast specificity of existing imaging approaches. Prior gadolinium (Gd)-enhanced MRI studies demonstrate global tracer distribution but yield spatially diffuse signals that do not resolve PVS at the level of individual vessels. Here we introduce an ultra-high-resolution dual-contrast MRI framework that enables vessel-resolved mapping of PVS across the whole brain in vivo. This approach combines ultra-high-field imaging, an implantable radiofrequency coil for enhanced local sensitivity, and intraventricular Gd delivery to achieve sufficient contrast and spatial specificity for detecting vessel-associated perivascular signal. Using this framework, we show that PVS are hierarchically organized along vascular trees, extending from major surface arteries into deep cortical and subcortical regions. Signal patterns along arterial branches and junctions indicate that PVS follows vascular topology. Quantitative analysis reveals that only a subset of penetrating vessels ([~]6%) exhibits detectable PVS signal, indicating heterogeneous organization across vascular networks independent of vessel caliber. Widespread detection of PVS, including in the hippocampus, further demonstrates that ventricularly delivered tracers access a distributed, vessel-associated perivascular network in vivo. These results establish an anatomical framework for mapping perivascular transport pathways across the brain, bridging global tracer imaging with vessel-resolved organization, and enabling investigation of how vascular architecture and fluid dynamics shape CSF-ISF exchange.

neuroscience↗

bioRxiv2025

Title: The RNA-binding protein TRIM71 is essential for hearing in humans and mice and regulates the timing of auditory sensory organ development

The RNA-binding protein TRIM71 is essential for brain development, and recent genetic studies in humans have identified TRIM71 as a risk gene for congenital hydrocephaly (CH). Here, we show that mono-allelic missense mutations in TRIM71 are associated with hearing loss (HL) and inner ear aplasia in humans. Utilizing conditional Trim71 knockout mice carrying a CH and HL-associated mutation, we demonstrate that loss of TRIM71 function during early otic development (embryonic day 9-10) causes severe hearing loss. While inner ear morphogenesis occurs normally in Trim71 knockout mice, we find that early otic loss of TRIM71 function disrupts the highly stereotyped timing of cell cycle exit and differentiation within the inner ear auditory sensory organ (cochlea), resulting in the premature formation and innervation of mechano-sensory hair cells. Transcriptomic profiling of Trim71 deficient cochlear progenitor cells identifies Inhba and Tgfbr2 as targets of TRIM71 repression, and our analysis of InhbaTgfbr1 double knockout mice indicates that TRIM71 maintains hair cell progenitors in a proliferative and undifferentiated state by restricting TGF-{beta}-type signaling. Characterization of hair cells and their associated neurons in adult Trim71 knockout mice revealed abnormally short inner hair cell stereocilia, reduced pre-synaptic terminals, and neuronal degeneration in the outer hair cell region, providing a basis for the observed hearing deficits in Trim71 knockout mice.

neuroscience↗

bioRxiv2023

Dual impact of PTEN mutation on CSF dynamics and cortical networks via the dysregulation of neural precursors and their interneuron descendants

Expansion of the cerebrospinal fluid (CSF)-filled cerebral ventricles (ventriculomegaly) is the quintessential feature of congenital hydrocephalus (CH) but also seen in autism spectrum disorder (ASD) and several neuropsychiatric diseases. PTEN is frequently mutated in ASD; here, we show PTEN is a bona fide risk gene for the development of ventriculomegaly, including neurosurgically-treated CH. Pten-mutant hydrocephalus is associated with aqueductal stenosis due to the hyperproliferation of periventricular Nkx2.1+ neural precursors (NPCs) and CSF hypersecretion from inflammation-dependent choroid plexus hyperplasia. The hydrocephalic Pten-mutant cortex exhibits ASD-like network dysfunction due to impaired activity of Nkx2.1+ NPC-derived inhibitory interneurons. Raptor deletion or post-natal Everolimus corrects ventriculomegaly, rescues cortical deficits, and increases survival by antagonizing mTORC1-dependent Nkx2.1+ cell pathology. These results implicate a dual impact of PTEN mutation on CSF dynamics and cortical networks via the dysregulation of NPCs and their interneuron descendants. These data identify a non-surgical treatment target for hydrocephalus and have implications for other developmental brain disorders. HIGHLIGHTSO_LIPTEN de novo mutations are associated with cerebral ventriculomegaly in autism spectrum disorder (ASD) and congenital hydrocephalus (CH). C_LIO_LIPten-mutant hydrocephalus is associated with aqueductal stenosis due to the hyperproliferation of medial ganglionic eminence Nkx2.1+ neural precursors and CSF hypersecretion from inflammation-induced choroid plexus hyperplasia. C_LIO_LIThe hydrocephalic Pten-mutant cortex exhibits ASD-like network dysfunction due to impaired activity of Nkx2.1+ NPC-derived inhibitory interneurons. C_LIO_LImTORC1 inhibition via Raptor deletion or early post-natal treatment with rapamycin or everolimus increases survival and ameliorates Pten-mutant ventriculomegaly and cortical pathology. C_LI

neuroscience↗

bioRxiv2020

Unique actions of GABA arising from cytoplasmic chloride microdomains

Developmental, cellular, and subcellular variations in the direction of neuronal Cl- currents elicited by GABAA receptor activation have been frequently reported, and we found a corresponding variance in the reversal potential (EGABA) for individual interneurons synapsing on a single pyramidal cell. These findings suggest a corresponding variance in the cytoplasmic concentration of Cl- ([Cl-i]). We determined [Cl-]i by: 1) two-photon imaging of the Cl- sensitive, ratiometric fluorescent protein SuperClomeleon (sCLM); 2) Fluorescence Lifetime IMaging (FLIM) of the Cl- sensitive fluorophore MEQ; and 3) electrophysiological measurements of EGABA. These methods collectively demonstrated stable [Cl-]i microdomains in individual neurons in vivo. Fluorometric and electrophysiological estimates of local [Cl-]i were highly correlated. [Cl-]i microdomains persisted after pharmacological inhibition of cation-chloride cotransporters (CCCs) but steadily decreased after inhibiting the polymerization of the anionic macromolecule actin. These studies highlight the existence of functionally significant neuronal Cl- microdomains that modify the impact of GABAergic inputs.

neuroscience↗

bioRxiv2020

Quantitative fluorescence lifetime imaging uncovers a novel role for KCC2 chloride transport in dendritic microdomains

Intracellular chloride ion ([Cl-]i) homeostasis is critical for synaptic neurotransmission yet variations in subcellular domains are poorly understood owing to difficulties in obtaining quantitative, high-resolution measurements of dendritic [Cl-]i. We combined whole-cell patch clamp electrophysiology with simultaneous fluorescence lifetime imaging (FLIM) of the Cl- dye MQAE to quantitatively map dendritic Cl- levels in normal or pathological conditions. FLIM-based [Cl-]i estimates were corroborated by Rubi-GABA uncaging to measured EGABA. Low baseline [Cl-]i in dendrites required Cl- efflux via the K+-Cl- cotransporter KCC2 (SLC12A5). In contrast, pathological NMDA application generated spatially heterogeneous subdomains of high [Cl-]i that created dendritic blebs, a signature of ischemic stroke. These discrete regions of high [Cl-]i were caused by reversed KCC2 transport. Therefore monitoring [Cl-]i microdomains with a new high resolution FLIM-based technique identified novel roles for KCC2-dependent chloride transport to generate dendritic microdomains with implications for disease.

neuroscience↗