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Wallace, M. L.

Publications and source records attributed to Wallace, M. L..

4 recordsLinked to original sources

Multidimensional profiling of heterogeneous lateral habenula subpopulations reveals distinct responses during motivated behavior

The lateral habenula (LHb) shapes reward and aversion learning via projections to midbrain monoaminergic centers. Recent studies have demonstrated significant genetic, anatomical, and electrophysiological diversity within the LHb. However, it remains unclear how genetic or intrinsic electrophysiological characteristics relate to in vivo neuronal activity patterns. Additionally, there are few descriptions of transgenic mouse lines labeling specific LHb neuronal subtypes. Here we describe spatial gene expression patterns, electrophysiological characteristics, and projection targets for specific subpopulations of neurons in the LHb targeted via existing transgenic mouse lines. Furthermore, we demonstrate that two genetically defined subpopulations differentially respond to value, prediction errors, and directional movement during flexible, reward-guided behavior. These findings indicate that specific, genetically targetable, neuronal subpopulations in LHb may control discrete aspects of motivated behavior through parallel circuits targeting serotonergic and dopaminergic midbrain centers.

neuroscience↗

Using a wearable EEG device to examine age trends in sleep macro- and micro-architecture across adolescence

Adolescence is a period of distinct maturational changes in sleep physiology. Age-related trends in sleep physiology have been captured using laboratory-based polysomnography, a method limited by logistical burden and high cost. We tested the ability of the accessible Dreem3 sleep EEG headband to replicate established age effects in sleep physiology from late childhood through early adulthood. Typically developing youth (N=100, 9-26 years) completed 3-4 consecutive nights of at-home sleep recording. We estimated age-related trends across eight macro-architecture and 15 micro-architecture variables with known age effects, and conducted exploratory analyses of 24 additional variables. Dreem replicated established age trends, including increases in non-rapid eye movement (NREM) stage 2, and decreases in N3, time in bed, NREM delta and theta power with increasing age. Exploratory analysis revealed age effects in twelve variables, including decreases in spindle activity with increasing age. Sleep EEG wearables offer an accessible way to characterize sleep physiology development.

neuroscience↗

Mixed representations of choice and outcome by GABA/glutamate cotransmitting neurons in the entopeduncular nucleus

The basal ganglia (BG) are an evolutionarily conserved and phylogenetically old set of sub-cortical nuclei that guide action selection, evaluation, and reinforcement. The entopeduncular nucleus (EP) is a major BG output nucleus that contains a population of GABA/glutamate cotransmitting neurons (EPSst+) that specifically target the lateral habenula (LHb) and whose function in behavior remains mysterious. Here we use a probabilistic switching task that requires an animal to maintain flexible relationships between action selection and evaluation to examine when and how GABA/glutamate cotransmitting neurons contribute to behavior. We find that EPSst+neurons are strongly engaged during this task and show bidirectional changes in activity during the choice and outcome periods of a trial. We then tested the effects of either permanently blocking cotransmission or modifying the GABA/glutamate ratio on behavior in well-trained animals. Neither manipulation produced detectable changes in behavior despite significant changes in synaptic transmission in the LHb, demonstrating that the outputs of these neurons are not required for on-going action-outcome updating in a probabilistic switching task.

neuroscience↗

Distinct neuronal subtypes of the lateral habenula differentially target ventral tegmental area dopamine neurons

The lateral habenula (LHb) is an epithalamic brain structure critical for processing and adapting to negative action outcomes. However, despite the importance of LHb to behavior and the clear anatomical and molecular diversity of LHb neurons, the neuron types of the habenula remain unknown. Here we use high-throughput single-cell transcriptional profiling, monosynaptic retrograde tracing, and multiplexed FISH to characterize the cells of the mouse habenula. We find 5 subtypes of neurons in the medial habenula (MHb) that are organized into anatomical subregions. In the LHb we describe 4 neuronal subtypes and show that they differentially target dopaminergic and GABAergic cells in the ventral tegmental area (VTA). These data provide a valuable resource for future study of habenular function and dysfunction and demonstrate neuronal subtype specificity in the LHb-VTA circuit.

neuroscience↗