Biology subjects

Araneda, R. C.

Publications and source records attributed to Araneda, R. C..

4 recordsLinked to original sources

bioRxiv2026

Proteome-Driven Phenotyping of Identified Single Neurons in Intact Brain Tissue by Aspiration Patch Proteomics

Single-cell proteomics has advanced rapidly, but direct proteome measurements from identified neurons in intact brain tissue remain difficult because most workflows require cell isolation and recent patch-based studies have emphasized whole-soma retrieval. Here we show that aspiration-based patch proteomics enables deep proteome profiling of identified single neurons directly in acute mouse brain slices. We combined fluorescence-guided patch-clamp microsampling, minimal-loss bottom-up proteomics, and high-sensitivity capillary electrophoresis-timsTOF mass spectrometry to analyze partial somal aspirates from dopaminergic, parvalbumin, and serotonergic neurons in situ. The workflow identified more than 1,000 proteins from single-neuron samples under optimized conditions while consuming only about 0.25% of the processed digest per analysis. These proteomes were sufficient to separate biological replicates by neuronal phenotype, distinguish neuronal subtypes on the basis of protein expression alone, and define a conserved somal proteome shared across neuronal classes. Our results establish that controlled aspiration of partial somal material can support proteome-driven phenotyping without whole-soma retrieval, cell dissociation, or loss of native tissue context. Aspiration patch proteomics therefore provides an accessible route for subtype-level proteome phenotyping in intact brain tissue.

neuroscience↗

bioRxiv2026

A fast and simple algorithm for accurate spike detection in HD-MEA recordings

BackgroundHigh density microelectrode arrays provide a strong platform to study individual neuronal activity and neuronal network dynamics. However, the analysis of high volume and complex data present several challenges. Common spike detection methods based on Root-Mean-Square (RMS) threshold crossing underestimate the number of spikes during neuronal bursting, which frequently occurs in neuronal cultures. In addition, the detection of action potentials by multiple electrodes makes spikes sorting a computationally expensive task. New MethodWe optimized a previously described detection method, based on the scaled median of absolute deviations (MED) that is more accurate during high rates of neuronal firing. In addition, we added a step to de-duplicate (DP) spikes recorded on multiple electrodes, which enhanced the accuracy of MED. The combined method of detection and de-duplication (DP-MED) is less computationally expensive and easier to implement than popular sorting alternatives like Kilosort-4. Results and ConclusionsDuring burst periods, the MED-based method detected over half of spikes that were undetected by the RMS-based method. To evaluate the performance of DP-MED, we simulated data that emulates neuronal activity recorded with HD-MEA. Across increasing firing rates, DP-MED shows more precision than Kilosort-4 but is slightly less accurate. After inducing high firing rate in cortical cultures with pharmacological stimulation, DP-MED detected a similar number of spikes than Kilosort-4, however, the analysis in Kilosort-4 was 40-fold more time-consuming. These results highlight the effectiveness of the DP-MED method in the context of drug screening using HD-MEAs.

neuroscience↗

bioRxiv2022

α2-ADRENERGIC MODULATION OF Ih IN ADULT-BORN GRANULE CELLS IN THE OLFACTORY BULB

In the olfactory bulb (OB), a large population of axon-less inhibitory interneurons, the granule cells (GCs), coordinate network activity and tune the output of principal neurons, the mitral and tufted cells (MCs), through dendrodendritic interactions. Furthermore, GCs undergo neurogenesis throughout life, providing a source of plasticity to the neural network of the OB. The function and integration of GCs in the OB is regulated by several afferent neuromodulatory signals, including noradrenaline (NA), a state-dependent neuromodulator that plays a crucial role in the regulation of cortical function and task-specific decision processes. However, the mechanisms by which NA regulates GC function are not fully understood. Here, we show that NA modulates hyperpolarization-activated currents (Ih) via the activation of 2-adrenergic receptors in adult-born GCs (abGCs), thus directly acting on channels that play essential roles in regulating neuronal excitability and network oscillations in the brain. This modulation affects the dendrodendritic output of GCs leading to an enhancement of lateral inhibition onto the MCs. Furthermore, we show that NA modulates subthreshold resonance in GCs, which could affect the temporal integration of abGCs. Together, these results provide a novel mechanism by which a state-dependent neuromodulator acting on Ih can regulate GC function in the bulb.

neuroscience↗

bioRxiv2021

Cholinergic modulation of distinct inhibitory domains in granule cells of the olfactory bulb

Early olfactory processing relies on a large population of inhibitory neurons in the olfactory bulb (OB), the granule cells (GCs). GCs inhibit the OB output neurons, the mitral and tufted cells (M/TCs), shaping their responses to odors both in the spatial and temporal domains, therefore, the activity of GCs is finely tuned by local and centrifugal excitatory and inhibitory inputs. While the circuit substrates underlying regulatory inputs onto GCs are well-established, how they are locally modulated remains unclear. Here, we examine the regulation of GABAergic inhibition onto GCs by acetylcholine, a main neuromodulatory transmitter released in the OB, by basal forebrain (BF) neurons. In acute brain slices from male and female mice, we show that activation of muscarinic acetylcholine receptors (mAChRs) produces opposing effects on local and centrifugal inhibition onto GCs. By using electrophysiology, laser uncaging and optogenetics we show that the kinetics of GABAergic currents in GCs could be correlated with distal and proximal spatial domains from where they originate, along the GC somatodendritic axis. Proximal inhibition from BF afferents, is suppressed by activation of M2/M4-mAChRs. In contrast, distal local inhibition from deep short axon cells (dSACs) is enhanced by activation of M3-mAChRs. Furthermore, we show that the cholinergic enhancement of distal inhibition in GCs reduces the extent of dendrodendritic inhibition in MCs. Interestingly, the excitatory cortical feedback, which also targets the proximal region of GCs, was not modulated by acetylcholine, suggesting that muscarinic activation shifts the synaptic balance towards excitation in GCs. Together, these results suggest that BF cholinergic inputs to the OB fine tune GC-mediated inhibition of M/TCs by differentially modulating the proximal and distal domains of inhibition in GCs.

neuroscience↗