Biology subjects

Konopka, G.

Publications and source records attributed to Konopka, G..

At least 19 recordsLinked to original sources

bioRxiv2026

Isoflurane anesthesia CNS recovery state: ultra-slow oscillations and cellular-stress-responsive gene expression

General anesthesia and NREM sleep share slow-wave EEG features, yet whether anesthesia substitutes for physiological sleep remains unclear. We compared recovery from 4h of isoflurane anesthesia (IA) with time-matched sleep and sleep deprivation (SD) in male C57BL/6J mice using continuous EEG/EMG recordings and frontal cortex RNA sequencing. IA recovery produced transient, rebound arousal, reduced early NREM and REM sleep, and, fragmented subsequent NREM bouts, and persistant, ultra-slow EEG-oscillations that normalized within two weeks. Whereas, SD induced consolidated rebound sleep and slow wave activity. Transcriptomic profiling at ZT6 showed that IA and SD induced largely distinct cortical gene-expression programs. IA preferentially enriched integrated stress response and unfolded protein response genes, whereas SD showed a comparatively orthogonal, growth-permissive, mTOR-associated profile. Although IA-induced gene-expression suggests cellular stress, corticosterone measurements argued against systemic stress as the primary driver. These findings indicate that isoflurane recovery is neurophysiologically and molecularly distinct from restorative sleep.

neuroscience↗

bioRxiv2026

Molecular and cell type-specific determinants of inferior colliculus development and auditory function

Sound perception requires sensory information processing through brain regions where alterations to cellular composition or function may impact auditory-relevant behaviors. The inferior colliculus (IC) is a central midbrain hub for integrating and transforming auditory information prior to relay to the forebrain. However, the molecular logic that underlies the cell type specification of the IC remains unknown. Here, using a multiomic approach, we define the transcriptional and chromatin landscapes that underlie IC cell type diversity. We identify distinct glutamatergic neuronal subclasses and the gene regulatory programs that drive their specification, maturation, and survival. We show that perturbation to the transcription factor FOXP2, previously implicated in speech and language as well as brain disorders with altered sensory processing, selectively disrupts the specification and survival of three newly defined glutamatergic neuronal subclasses. We link these molecular and cellular disruptions to functional deficits in auditory processing including altered brainstem and forebrain responses and impaired behavioral sensitivity to acoustic stimuli. Together, these results link gene regulatory mechanisms to cell type-specification in the IC, providing insight into how molecular control of neuronal identity in midbrain sensory centers contributes to systems-level processing of sound.

neuroscience↗

bioRxiv2026

The genetic signature of memory encoding along the human hippocampal axis

Episodic memory formation engages hippocampal oscillations that vary along the anterior-posterior axis, but the molecular programs supporting this physiological specialization remain unclear. Here, we leveraged a rare neurosurgical dataset in which patients performed verbal episodic memory tasks during intrahippocampal intracranial EEG recordings prior to en bloc hippocampal resection, enabling integration of encoding-related oscillatory signatures with matched cell-type-resolved transcriptomics from the same individuals. Subsequent memory effects (SMEs) spanned delta/theta, gamma, and hippocampal ripple activity across anterior and posterior hippocampus. Single-nucleus RNA sequencing from anatomically matched anterior and posterior tissue revealed longitudinal transcriptional gradients, most prominent in excitatory neurons. Spatial transcriptomic maps validated axis-enriched transcripts and their localization. Linking subject-specific SMEs to gene expression identified distinct molecular programs: anterior low frequency SMEs associated with synaptic and chromatin-regulatory pathways, and posterior high-frequency SMEs associated with metabolic and protein synthesis processes. Gene regulatory network inference further revealed axis-specific hub architectures. Together, these results define a cell-type-specific genetic architecture linking longitudinal molecular specialization to the human hippocampal encoding dynamics.

neuroscience↗

bioRxiv2026

Evolution of songbird vocal imitation involved multiple cellular innovations

A central goal of evolutionary neuroscience is to link behavioral adaptations to changes across the central nervous system. The dorsal telencephalon (i.e., pallium) varies widely in macrostructure across vertebrate clades and is thought to underlie the diversity of complex vertebrate behaviors. Yet, pallial cell types appear comparatively constrained in their evolutionary specializations relative to other parts of the nervous system, even across species with notable behavioral adaptations. Instead, differences among pallial neurons largely reflect their topographic organization. Here, we show that although transcriptomic identities of cell types in the songbird pallium largely follow this pattern, multiple cellular innovations exist within the vocal imitation brain regions distributed across the pallium. These include behavior-linked specializations to glutamatergic cell types in each region and the presence of PV- and SST-like GABAergic neurons unique to vocal imitation circuits. Additionally, we identify a concerted increase in glial composition that is accounted for by elevated proportions of astrocytes across vocal imitation circuits. These findings demonstrate that complex learned behaviors, such as vocal imitation, can be associated with the emergence of novel, behavior-associated cell types in the pallium; suggesting that selective pressures can, in some uncommon cases, favor functional specialization over conserved developmental constraints.

neuroscience↗

bioRxiv2025

Stimulation modulates cell assemblies linked with gene networks in the human temporal cortex ex vivo

Deep brain stimulation of the temporal cortex can enhance learning and memory in the face of cognitive impairment. Despite the potential of such therapies, the neural and genetic mechanisms underlying the effect of stimulation on human brain circuits are not understood. To explicate direct mechanisms of neural modulation elicited by brain stimulation, we developed an ex vivo approach utilizing microelectrode array stimulation and recording of resected temporal cortex from neurosurgical patients. We find that stimulation preferentially increases firing rates in pyramidal cells compared to interneurons and also strengthens cell assemblies. Using single cell multiomics, we link the observed physiological changes to cell type-specific gene expression patterns. We detail gene regulatory networks that indicate preferential involvement of specific excitatory neuron subtypes and the response of non-neurons. We conclude that the overall impact of stimulation on the human temporal cortex is activation of specific excitatory neurons and enhanced cell assembly activity, and that these changes are supported by gene networks involving immediate early, synaptic, and ion channel genes. Our findings establish a foundation to identify targetable cell type-specific genetic signatures that may be harnessed for therapeutic benefit in future neuromodulation strategies.

neuroscience↗

bioRxiv2025

Evolution of the cellular landscape in mammalian striatum

The dorsal striatum is important for highly specialized functions including movement, learning, and habit formation. However, it is not known if species-specialized behaviors are associated with cellular specializations in the striatum. Here, we compared single-nucleus RNA sequencing (snRNA-seq) data from human, chimpanzee, rhesus macaque, common marmoset, and pale spear-nosed bat caudate (CN) and putamen (Pu) separately as well as mouse caudoputamen (C-Pu), which represents divergence among species spanning approximately 94 million years of evolution. We observed a lower neuron-to-glia ratio in primate striata compared to non-primates, reflecting the allometric scaling of neuron density and relative glia density invariance in larger brains. Among neurons, eccentric spiny projection neurons (eSPNs) - an SPN of unknown function - showed significantly lower proportions in non-primate striata for both CN and Pu. Focusing on the heterogeneity within interneurons, we identified two bat striatal interneuron cell types that are nearly absent in other species: which express LMO3, and co-express FOXP2 and TSHZ2. Other striatal interneurons also showed significantly differential abundance between primates and non-primates. In summary, we provide a comprehensive snRNA- seq dataset of dorsal striatum, identify novel interneuron innovations in bat, and uncover fundamental cellular composition differences between primate and non-primate striata.

genomics↗

bioRxiv2025

Resilience to Endoplasmic Reticulum Stress Mitigates Calcium-Dependent Membrane Hyperexcitability Underlying Late Disease Onset in SCA6

An enduring puzzle in many inherited neurological disorders is the late onset of symptoms despite expression of function-impairing mutant protein early in life. We examined the basis for onset of impairment in Spinocerebellar ataxia type 6 (SCA6), a canonical late-onset neurodegenerative ataxia which results from a polyglutamine expansion in the voltage gated calcium channel, Cav2.1. Cerebellar Purkinje cell spiking abnormalities are seen concurrent with motor impairment in SCA6 mice but the basis for these changes in spiking is unknown. We identify endoplasmic reticulum (ER) calcium depletion as the cause for Purkinje cell spiking abnormalities and that the impairments in Purkinje cell spiking are unrelated to Cav2.1 ion-flux function. Further, intact inhibitory neurotransmission in the cerebellar cortex is necessary for Purkinje neurons to exhibit spiking abnormalities in SCA6 mice. Based on serial cerebellar transcriptome analysis, we define a mechanism of disease that is related to ER stress. Further, our studies support a model whereby proteotoxicity from misfolded mutant Cav2.1 is mitigated by a HSP90-dependent unfolded protein response (UPR) and that age-related breakdown of this response causes motor dysfunction and aberrant Purkinje cell spiking. Redundant pathways of the UPR mediate this resilience to ER stress. These studies elucidate a mechanism of resilience connecting aberrant proteostasis and calcium-dependent intrinsic membrane hyperexcitability to explain delayed disease onset more widely in age-dependent neurodegenerative disease. Significance StatementAdvancing age is the single most important risk factor for neurodegenerative disease. Understanding how age intersects with genetic risk is therefore a critical challenge for neurodegenerative disease research. SCA6, a canonical late-onset degenerative cerebellar ataxia, results from a polyQ expansion in the voltage gated calcium channel, Cav2.1, encoded by CACNA1A. We define a mechanism of disease in SCA6 that is related to ER stress and unrelated to impaired calcium flux function of Cav2.1. Age-related decompensation of a HSP90-dependent unfolded protein response leads to disease onset. Mutant Cav2.1 misfolding as the basis for disease in SCA6 provides insight into a novel role for channelopathies to behave as proteinopathies and helps understand resilience to proteotoxicity more widely in adult-onset neurodegenerative disease.

neuroscience↗

bioRxiv2024

Cell type specific roles of FOXP1 during early neocortical murine development

FOXP1, a transcription factor enriched in the neocortex, is associated with autism spectrum disorders (ASD) and FOXP1 syndrome. Emx1Cre/+;Foxp1fl/flconditional deletion (Foxp1 cKO) in the mouse cortex leads to overall reduced cortex thickness, alterations in cortical lamination, and changes in the relative thickness of cortical layers. However, the developmental and cell type-specific mechanisms underlying these changes remained unclear. We find that Foxp1 deletion results in accelerated pseudo-age during early neurogenesis, increased cell cycle exit during late neurogenesis, altered gene expression and chromatin accessibility, and selective migration deficits in a subset of upper-layer neurons. These data explain the postnatal differences observed in cortical layers and relative cortical thickness. We also highlight genes regulated by FOXP1 and their enrichment with high-confidence ASD or synaptic genes. Together, these results underscore a network of neurodevelopmental disorder-related genes that may serve as potential modulatory targets for postnatal modification relevant to ASD and FOXP1 syndrome.

neuroscience↗

bioRxiv2024

Sleep need driven oscillation of glutamatergic synaptic phenotype

Sleep loss increases AMPA-synaptic strength and number in the neocortex. However, this is only part of the synaptic sleep loss response. We report increased AMPA/NMDA EPSC ratio in frontal-cortical pyramidal neurons of layers 2-3. Silent synapses are absent, decreasing the plastic potential to convert silent NMDA to active AMPA synapses. These sleep loss changes are recovered by sleep. Sleep genes are enriched for synaptic shaping cellular components controlling glutamate synapse phenotype, overlap with autism risk genes and are primarily observed in excitatory pyramidal neurons projecting intra-telencephalically. These genes are enriched with genes controlled by the transcription factor, MEF2c and its repressor, HDAC4. Sleep genes can thus provide a framework within which motor learning and training occurs mediated by sleep-dependent oscillation of glutamate-synaptic phenotypes.

neuroscience↗

bioRxiv2023

FOXP1 regulates the development of excitatory synaptic inputs onto striatal neurons and induces phenotypic reversal with reinstatement

Long-range glutamatergic inputs from the cortex and thalamus are critical for motor and cognitive processing in the striatum. Transcription factors that orchestrate the development of these inputs are largely unknown. We investigated the role of a transcription factor and high-risk autism-associated gene, FOXP1, in the development of glutamatergic inputs onto spiny projection neurons (SPNs) in the striatum. We find that FOXP1 robustly drives the strengthening and maturation of glutamatergic input onto dopamine receptor 2-expressing SPNs (D2 SPNs) but has a comparatively milder effect on D1 SPNs. This process is cell-autonomous and is likely mediated through postnatal FOXP1 function at the postsynapse. We identified postsynaptic FOXP1-regulated transcripts as potential candidates for mediating these effects. Postnatal reinstatement of FOXP1 rescues electrophysiological deficits, reverses gene expression alterations resulting from embryonic deletion, and mitigates behavioral phenotypes. These results provide support for a possible therapeutic approach for individuals with FOXP1 syndrome.

neuroscience↗

bioRxiv2023

Decoding DNA sequence-driven evolution of the human brain epigenome at cellular resolution

DNA-based evolutionary comparisons of regulatory genomic elements enable insight into functional changes, overcoming tissue inaccessibility. Here, we harnessed adult and fetal cortex single-cell ATAC-seq datasets to uncover DNA substitutions specific to the human and human-ancestral lineages within apes. We found that fetal microglia identity is evolutionarily divergent in all lineages, whereas other cell types are conserved. Using multiomic datasets, we further identified genes linked to multiple lineage-divergent gene regulatory elements and implicated biological pathways associated with these divergent features. We also uncovered patterns of transcription factor binding site evolution across lineages and identified expansion of bHLH-PAS factor targets in human-hominin lineages, and MEF2 factor targets in the ape lineage. Finally, conserved features were more enriched in brain disease variants, whereas there was no distinct enrichment on the human lineage compared to its ancestral lineages. Our study identifies major evolutionary patterns in the human brain epigenome at cellular resolution.

genomics↗

bioRxiv2023

Compensation between FOXP transcription factors maintains proper striatal function

Spiny projection neurons (SPNs) of the striatum are critical in integrating neurochemical information to coordinate motor and reward-based behavior. Mutations in the regulatory transcription factors expressed in SPNs can result in neurodevelopmental disorders (NDDs). Paralogous transcription factors Foxp1 and Foxp2, which are both expressed in the dopamine receptor 1 (D1) expressing SPNs, are known to have variants implicated in NDDs. Utilizing mice with a D1-SPN specific loss of Foxp1, Foxp2, or both and a combination of behavior, electrophysiology, and cell-type specific genomic analysis, loss of both genes results in impaired motor and social behavior as well as increased firing of the D1-SPNs. Differential gene expression analysis implicates genes involved in autism risk, electrophysiological properties, and neuronal development and function. Viral mediated re-expression of Foxp1 into the double knockouts was sufficient to restore electrophysiological and behavioral deficits. These data indicate complementary roles between Foxp1 and Foxp2 in the D1-SPNs.

neuroscience↗

bioRxiv2023

An extra-circadian function for human CLOCK in the neocortex

Core circadian-related proteins such as the transcription factor CLOCK are ubiquitously expressed and important for regulating molecular pathways underlying circadian rhythms. Previous work has suggested that CLOCK has evolved human neocortex-specific gene regulation and therefore may have extra-circadian functions. To test this in vivo, we generated a mouse model that recapitulates human cortical expression of CLOCK. The CLOCK humanized (HU) mice show enhanced cognitive flexibility, which is associated with the alteration in spatiotemporal expression of CLOCK. Cell type specific genomic profiling of HU mice identified upregulated genes related to dendritic growth and spine formation in excitatory neurons. Consistent with this result, we found that excitatory neurons in HU mice have increased complexity of dendritic branching and spine density, as well as a greater frequency of excitatory postsynaptic currents, suggesting an increase in neural connectivity. In contrast, CLOCK knockout in human induced pluripotent stem cell-induced neurons showed reduced complexity of dendrites and lower density of presynaptic puncta. Together, our data demonstrate that CLOCK evolved extra-circadian gains of function via altered spatiotemporal gene expression and these functions may underlie human brain specializations.

neuroscience↗

bioRxiv2022

A single-cell trajectory atlas of striatal development

The striatum integrates dense neuromodulatory inputs from many brain regions to coordinate complex behaviors. This integration relies on the coordinated responses from distinct striatal cell types. While previous studies have characterized the cellular and molecular composition of the striatum using single-cell RNA-sequencing at distinct developmental timepoints, the molecular changes spanning embryonic through postnatal development at the single-cell level have not been examined. Here, we combine published mouse striatal single-cell datasets from both embryonic and postnatal timepoints to analyze the developmental trajectory patterns and transcription factor regulatory networks within striatal cell types. Using this integrated dataset, we found that dopamine receptor-1 expressing spiny projection neurons have an extended period of postnatal development with greater transcriptional complexity compared to dopamine receptor-2 expressing neurons. Moreover, we found the transcription factor, FOXP1, exerts indirect changes to oligodendrocytes. These data can be accessed and further analyzed through an interactive website (https://cells-test.gi.ucsc.edu/?ds=mouse-striatal-dev).

neuroscience↗

bioRxiv2022

FOXP1 orchestrates neurogenesis in human cortical basal radial glial cells

During cortical development, human basal radial glial cells (bRGCs) are highly capable of sustained self-renewal and neurogenesis. Selective pressures on this cell type may have contributed to the evolution of the human neocortex, leading to an increase in cortical size. bRGCs have enriched expression for Forkhead Box P1 (FOXP1), a transcription factor implicated in neurodevelopmental disorders such as autism spectrum disorder. However, the cell type-specific roles of FOXP1 in bRGCs during cortical development remain unexplored. Here, we examine the requirement for FOXP1 gene expression regulation underlying the production of bRGCs using human brain organoids. We examine a developmental time point when FOXP1 expression is highest in the cortical progenitors, and the bRGCs, in particular, begin to actively produce neurons. With the loss of FOXP1, we show a reduction in the number of bRGCs, as well as reduced proliferation and differentiation of the remaining bRGCs, all of which lead to reduced numbers of excitatory cortical neurons over time. Using single-nuclei RNA sequencing and cell trajectory analysis, we uncover a role for FOXP1 in directing cortical progenitor proliferation and differentiation by regulating key signaling pathways related to neurogenesis and neurodevelopmental disorders. Together, these results demonstrate that FOXP1 regulates human-specific features in early cortical development.

neuroscience↗

bioRxiv2022

Ambient RNA analysis reveals misinterpreted and masked cell types in brain single-nuclei datasets

Ambient RNA contamination in single-cell RNA sequencing (RNA-seq) is a significant problem, but its consequences are poorly understood. Here, we show that ambient RNAs in brain single-nuclei RNA-seq can have a nuclear or extra-nuclear origin with distinct gene set signatures. Both ambient RNA signatures are predominantly neuronal and we find that some previously annotated neuronal cell types are distinguished by ambient RNA. Strikingly, we also detect pervasive neuronal ambient RNA contamination in all glial cell types unless glia and neurons are physically separated prior to sequencing. We demonstrate that this contamination can be removed in silico. We also show that previous annotations of immature oligodendrocytes are likely glial cells contaminated with ambient RNAs. After ambient RNA removal, we detect extremely rare, committed oligodendrocyte progenitor cells, which were infrequently annotated in previous adult human brain datasets. Together, these results provide an in-depth analysis of ambient RNA contamination in brain single-cell datasets.

neuroscience↗

bioRxiv2020

Zbtb16 regulates social cognitive behaviors and neocortical development.

Recent genetic studies have underscored the pleiotropic effects of single genes to multiple cognitive disorders. Mutations of ZBTB16 are associated with autism spectrum disorder (ASD) and schizophrenia (SCZ), but how the function of ZBTB16 is related to ASD or SCZ remains unknown. Here we show the deletion of Zbtb16 in mice leads to both ASD- and SCZ-like behaviors such as social impairment, repetitive behaviors, risk-taking behaviors, and cognitive impairment. To elucidate the mechanism underlying the behavioral phenotypes, we carried out histological studies and observed impairments in thinning of neocortical layer 6 (L6) and a reduction of TBR1+ neurons in the prefrontal cortex (PFC) of Zbtb16 KO mice. Furthermore, we found increased dendritic spines and microglia as well as developmental defects in oligodendrocytes and neocortical myelination in the PFC of Zbtb16 KO mice. Using a genomics approach, we identified the Zbtb16-transcriptome that includes genes involved in both ASD and SCZ pathophysiology and neocortical maturation such as neurogenesis and myelination. Co-expression networks further identified Zbtb16-correlated modules that are unique to ASD or SCZ respectively. Our study provides insight into the differential role of ZBTB16 in ASD and SCZ.

neuroscience↗

bioRxiv2020

FOXP1 negatively regulates intrinsic excitability in D2 striatal projection neurons by promoting inwardly rectifying and leak potassium currents

Heterozygous loss-of-function mutations in the transcription factor FOXP1 are strongly associated with autism. Dopamine receptor 2 expressing (D2) striatal projection neurons (SPNs) in heterozygous Foxp1 (Foxp1+/-) mice have higher intrinsic excitability. To understand the mechanisms underlying this alteration, we examined SPNs with cell-type specific homozygous Foxp1 deletion to study cell-autonomous regulation by Foxp1. As in Foxp1+/- mice, D2 SPNs had increased intrinsic excitability with homozygous Foxp1 deletion. This effect involved postnatal mechanisms. The hyperexcitability was mainly due to down-regulation of two classes of potassium currents: inwardly rectifying (KIR) and leak (KLeak). Single-cell RNA sequencing data from D2 SPNs with Foxp1 deletion indicated the down-regulation of transcripts of candidate ion channels that may underlie these currents: Kcnj2 and Kcnj4 for KIR and Kcnk2 for KLeak. This Foxp1-dependent regulation was neuron-type specific since these same currents and transcripts were either unchanged, or very little changed, in D1 SPNs with cell-specific Foxp1 deletion. Our data are consistent with a model where FOXP1 negatively regulates the excitability of D2 SPNs through KIR and KLeak by transcriptionally activating their corresponding transcripts. This, in turn, provides a novel example of how a transcription factor may regulate multiple genes to impact neuronal electrophysiological function that depends on the integration of multiple current types - and do this in a cell-specific fashion. Our findings provide initial clues to altered neuronal function and possible therapeutic strategies not only for FOXP1-associated autism but also for other autism forms associated with transcription factor dysfunction.

neuroscience↗