This year eNeuro is celebrating 10 years of publishing by highlighting select papers from throughout its history. This episode features a 2018 paper titled, "RNA from Trained Aplysia Can Induce an Epigenetic Engram for Long-Term Sensitization in Untrained Aplysia," and showcases interviews with David Glanzman and Alexis Bédécarrats.

Keshov Sharma and Lizabeth Romanski discuss their paper, “Neuronal Population Encoding of Identity in Primate Prefrontal Cortex,” published in Vol. 44, Issue 6 of JNeurosci, with Editor-in-Chief Cabine Kastner.

Emilia Lefevre discusses her paper, “Differential Patterns of Synaptic Plasticity in the Nucleus Accumbens Caused by Continuous and Interrupted Morphine Exposure,” published in Vol. 43, Issue 2 of JNeurosci in 2023, with Megan Sansevere from SfN’s Journals’ staff.

Many behaviors that are essential for survival, such as retrieving food, finding shelter and locating predator cues, rely on forming effective associations between the identity and location of spatial elements. This identity-location association is commonly assessed in rodents using spontaneous object-in-place (OiP) recognition memory tasks. OiP recognition memory deficits are seen in autism spectrum disorder, schizophrenia, and are used to detect early onset of Alzheimer’s disease. These deficits are replicated in animal models of neurodevelopmental, neurodegenerative and chromosomal disorders. The ventral hippocampus has been implicated in object recognition, but its contribution to OiP memory has not been established. Despite the broad adoption of mouse models in behavioral and systems neuroscience research for their ease of genetic manipulations, the neural correlates of OiP memory in mice remain unknown. Here we used chemogenetics to assess the contribution of the ventral and intermediate CA1 (vCA1 an...

Thalamocortical (TC) cells relay sensory information to the cortex, as well as driving their own feedback inhibition through collateral excitation of the thalamic reticular nucleus (TRN). Inhibitory TRN cells are extensively coupled through electrical synapses. While electrical synapses are most often noted for synchronizing rhythmic forms of neuronal activity, their modulation of transient neuronal signals is less understood. Here we sought to characterize how electrical synapses embedded within a network of TRN neurons regulate the processing of ongoing sensory inputs during relay from thalamus to cortex. We constructed a thalamocortical network consisting of reciprocally connected Hodgkin-Huxley-style TC and TRN cells and one cortical output cell summing the TC activity. TRN cells were each electrically coupled to two neighboring cells, forming a ring topology. TC cells received synaptic inputs in sequence, with input separated by 10 - 50 ms, allowing us to assess the functional radius of an electrical ...

Read onto learn about Claire Robey, a fifth-year PhD student at Uniformed Services University hoping to address the lack of sex-disaggregated data in traumatic brain injury (TBI) research as a 2024 ECPA.

Research program analyst Jaya Viswanathan, PhD, explores how she planned and executed two Brain Awareness Week (BAW) events with the goals in mind to develop neuroscience knowledge in younger audiences, as well as engage the local community in discussions about the brain.

Missense variants in O-GlcNAc transferase (OGT) result in OGT congenital disorder of glycosylation (OGT-CDG), an intellectual disability syndrome associated with O-GlcNAc dyshomeostasis and a range of neurodevelopmental defects. Inhibition of O-GlcNAcase (OGA), the enzyme responsible for removing protein O-GlcNAcylation, has been explored as a target for modulating brain O-GlcNAc homeostasis in neurodegenerative diseases and may also be a target for OGT-CDG. Here, we describe an OGT-CDG mouse line, studied in male mice, that exhibits microcephaly, motor deficits, and brain O-GlcNAc dyshomeostasis, closely mirroring patient symptoms. We genetically explored OGA as a target for OGT-CDG by crossing these mice with a line carrying catalytically inactive OGA. Encouragingly, this partially restored O-GlcNAc homeostasis in brain and blood as determined by Ogt/Oga mRNA ratio. These findings suggest that OGA inhibition can modulate enzymatic imbalance in OGT-CDG mice possessing microcephaly and motor deficits and t...

Dysregulation of Ca2+ homeostasis in cochlear outer hair cells (OHCs) is associated with impaired hearing following noise exposure. Ca2+ signaling in developing OHCs is modulated by oncomodulin (OCM), an EF-hand calcium-binding protein. Here, we investigated whether the lack of OCM disrupts Ca2+ signaling in mature OHCs and influences vulnerability to moderate noise. Using young adult CBA/CaJ mice of either sex, we found that OHCs from Ocm knock-out ( Ocm−/− ) mice showed comparable electromotile responses and synaptic innervation compared with littermate controls. Prior to noise exposure, Ocm −/− mice had auditory brainstem responses with highly variable latencies and amplitudes compared with Ocm +/+ mice. Moderate noise exposure (95 dB SPL, 2 h) caused temporary threshold shifts in wild-type ( Ocm +/+) mice but PTS in Ocm −/− mice. Using a genetically encoded Ca2+ sensor (GCaMP6s) expressed in OHCs, we found increased GCaMP6s fluorescence and ATP-induced Ca2+ signaling in Ocm −/− OHCs. Using GCaMP6s mice...

Inhibitory synapse formation is poorly understood compared with excitatory synaptogenesis, in part because the molecular events underlying assembly occur asynchronously and on timescales that have been difficult to resolve. Here, we exploit the ability of Semaphorin 4D (Sema4D) to rapidly and selectively induce GABAergic synapse formation in cultured hippocampal neurons, synchronizing these events to enable direct observation of pre- and postsynaptic protein dynamics by two-channel live imaging. We find that Sema4D promotes a population-wide increase in the mobility of GAD65-containing presynaptic boutons within 20 min of treatment while postsynaptic gephyrin scaffolds are mobilized only locally in a proximity-dependent manner, consistent with a presynapse-first model of inhibitory synapse assembly. Sema4D also drives recruitment of GABAARγ2 subunits to receptor-poor postsynaptic gephyrin scaffolds within 10 min of treatment, prior to detectable changes in GAD65–gephyrin colocalization, suggesting that pos...