Biology subjects

Clayton, K. K.

Publications and source records attributed to Clayton, K. K..

5 recordsLinked to original sources

bioRxiv2025

Layer 6 is a hub for cholinergic modulation in the mouse auditory cortex

AbstractBasal forebrain cholinergic neurons (BFCNs) densely innervate auditory cortex (ACtx), conveying signals linked to internal brain states and external sensory cues. Several studies have shown that acetylcholine (ACh) rapidly modifies local cortical circuits via nicotinic ACh receptors (nAChRs) on layer 1 (L1) inhibitory neurons. BFCN terminals are also abundant in L6, though the mechanisms and functional consequences of cholinergic modulation in deeper cortical layers has received less attention. Here, we performed multi-plex in situ labeling across cortical layers and cell types and found that L6 pyramidal neurons (L6-PNs) were highly enriched in diverse nAChR subunit and muscarinic ACh receptor (mAChR) transcripts. In vivo optogenetic activation of BFCN axons revealed persistent modulation of regular spiking (RS) units in L2-6 but a rapid phasic activation only in L6. In acute slices, optogenetic activation of BFCN axons elicited fast excitatory post-synaptic potentials via nAChRs in L6-PNs, comparable to responses in L1-INs, and slower inhibitory responses mediated by mAChRs. These findings identify L1 inhibitory neurons and L6 excitatory neurons as two hubs that mediate BFCN modulation of cortical circuits. Transcriptional, synaptic, and local circuit connectivity differences between L1 and L6 hubs may allow BFCN inputs to shape perception and plasticity on distinct timescales.

neuroscience↗

bioRxiv2024

Cortical determinants of loudness perception and auditory hypersensitivity

Parvalbumin-expressing inhibitory neurons (PVNs) stabilize cortical network activity, generate gamma rhythms, and regulate experience-dependent plasticity. Here, we observed that activation or inactivation of PVNs functioned like a volume knob in the mouse auditory cortex (ACtx), turning neural and behavioral classification of sound level up or down over a 20dB range. PVN loudness adjustments were "sticky", such that a single bout of 40Hz PVN stimulation sustainably suppressed ACtx sound responsiveness, potentiated feedforward inhibition, and behaviorally desensitized mice to loudness. Sensory sensitivity is a cardinal feature of autism, aging, and peripheral neuropathy, prompting us to ask whether PVN stimulation can persistently desensitize mice with ACtx hyperactivity, PVN hypofunction, and loudness hypersensitivity triggered by cochlear sensorineural damage. We found that a single 16-minute bout of 40Hz PVN stimulation session restored normal loudness perception for one week, showing that perceptual deficits triggered by irreversible peripheral injuries can be reversed through targeted cortical circuit interventions.

neuroscience↗

bioRxiv2023

Sound elicits stereotyped facial movements that provide a sensitive index of hearing abilities

Sound elicits rapid movements of muscles in the face, ears, and eyes that protect the body from injury and trigger brain-wide internal state changes. Here, we performed quantitative facial videography from mice resting atop a piezoelectric force plate and observed that broadband sounds elicit rapid, small, and highly stereotyped movements of a facial region near the vibrissae array. Facial motion energy (FME) analysis revealed sensitivity to far lower sound levels than the acoustic startle reflex and greater reliability across trials and mice than sound-evoked pupil dilations or movement of other facial and body regions. FME tracked the low-frequency envelope of sounds and could even decode speech phonemes in varying levels of background noise with high accuracy. FME growth slopes were disproportionately steep in mice with autism risk gene mutations and noise-induced sensorineural hearing loss, providing an objective behavioral measure of sensory hyper-responsivity. Increased FME after noise-induced cochlear injury was closely associated with the emergence of excess gain in later waves of the auditory brainstem response, suggesting a midbrain contribution. Deep layer auditory cortex units were entrained to spontaneous facial movements but optogenetic suppression of cortical activity facilitated - not suppressed - sound-evoked FME, suggesting the auditory cortex is a modulator rather than a mediator of sound-evoked facial movements. These findings highlight a simple involuntary behavior that is more sensitive and integrative than other auditory reflex pathways and captures higher-order changes in sound processing from mice with inherited and acquired hearing disorders.

neuroscience↗

bioRxiv2020

Motor corollary discharge activates layer six circuits in the auditory cortex

Optogenetic activation of Ntsr1+ layer 6 corticothalamic (L6 CT) neurons modulates thalamocortical sensory processing and perception for hundreds of milliseconds following laser offset. Naturally occurring sources of extrasensory inputs that could recruit L6 CTs prior to upcoming sensory stimuli have not been identified. Here, we found that 100% of L6 CTs in mouse primary auditory cortex (A1) expressed FoxP2, a protein marker found in brain areas that coordinate sensory inputs with movement. To test the idea that motor preparatory inputs could be a natural extrasensory activator of L6 CTs, we combined quantitative videography, optogenetically targeted single unit recordings, and two-photon imaging during self-initiated behavior. We found that A1 L6 CTs were activated hundreds of milliseconds prior to orofacial movements, but not whole-body movements associated with locomotion. These findings identify new local circuit arrangements for routing motor corollary discharge into A1 and suggest new roles for CT neurons in active sensing.

neuroscience↗

bioRxiv2019

Cellular and widefield imaging of sound frequency organization in primary and higher-order fields of the mouse auditory cortex

The mouse auditory cortex (ACtx) contains two core fields - A1 and AAF - arranged in a mirror reversal tonotopic gradient. The best frequency (BF) organization and naming scheme for additional higher-order fields remain a matter of debate, as does the correspondence between smoothly varying global tonotopy and heterogeneity in local cellular tuning. Here, we performed chronic widefield and 2-photon calcium imaging from the ACtx of awake Thy1-GCaMP6s reporter mice. Data-driven parcellation of widefield maps identified five fields, including a previously unidentified area at the ventral posterior extreme of the ACtx (VPAF) and a tonotopically organized suprarhinal auditory field (SRAF) that extended laterally as far as ectorhinal cortex. Widefield maps were stable over time, where single pixel BFs fluctuated by less than 0.5 octaves during a one-month imaging period. After accounting for neuropil signal and frequency tuning strength, BF organization in neighboring layer 2/3 neurons was intermediate to the heterogeneous salt and pepper organization and the highly precise local organization that have each been described in prior studies. Multiscale imaging data suggest there is no ultrasonic field or secondary auditory cortex in the mouse. Instead, VPAF and a dorsoposterior field (DP) emerged as the strongest candidates for higher-order auditory areas.

neuroscience↗