Substance use disorder (SUD) is characterized by maladaptive patterns of reward-seeking behavior. Such behavior has been linked to neuronal ensembles, typically identified through activity-dependent expression. These ensembles have been studied in regions such as the prelimbic prefrontal cortex (PL) and the nucleus accumbens core (NAcore). In this study, we characterized ensembles tagged during concurrent exposure to cocaine- and chocolate-associated contexts. We used 33 male and 33 female Ai14xFos2A-iCreERT2 (c-Fos-TRAP2) transgenic mice to tag neuronal ensembles in a dual cocaine-chocolate conditioned place preference (CPP) paradigm, in which each chamber was associated with a different reward, either cocaine or chocolate. We found that after successful dual conditioning and in the absence of rewards, mice preferred the cocaine-paired chamber to the chocolate-paired chamber. Additionally, in mice exposed to both cocaine and chocolate, cortical and accumbal ensembles (measured as tdTomato+ cell density) t...

Mary Kate Joyce discusses her paper, “Subgenual and Hippocampal Pathways in Amygdala Are Set to Balance Affect and Context Processing,” published in Vol. 43, Issue 17 of JNeurosci in 2023, with Megan Sansevere from SfN’s Journals’ staff.

Aaron Nichols discusses his paper, “Selective Serotonin Reuptake Inhibitors within Cells: Temporal Resolution in Cytoplasm, Endoplasmic Reticulum, and Membrane,” published in Vol. 43, Issue 13 of JNeurosci in 2023, with Megan Sansevere from SfN’s Journals’ staff.

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.

Studies of visual discrimination in rodents can confound the effects of cue salience with reward value making it difficult to determine which factor guides choice behavior. We examined this issue by testing how changes in relative salience affect decision dynamics in rats (nine females and five males) performing a two-alternative forced-choice task with visual cues associated with high or low sucrose rewards. After initial training with high and low luminance cues, we introduced a novel cue of intermediate luminance as a “luminance shift” test. The intermediate luminance cue substituted for either the brighter or dimmer cue and had the same reward value as the replaced cue. We found that while rats maintained a preference for the higher-value option, the introduction of a perceptually more similar cue reduced choice preference and eliminated latency differences compared to baseline. Using drift diffusion modeling, we found that the luminance shifts caused a reduction in the drift rate and had no effects on...

Our brain is in constant change due to neural plasticity, but, still, our experience of the world feels relatively stable to us. Focusing on visual processing, we hypothesise that brain responses to stimuli may change over long periods of time, but in a way that is orthogonal to the dimensions that are relevant to stimulus category discrimination. To test this hypothesis, we acquired and analysed a MEG dataset containing recordings from one female adult participant, with several scanning days spanning over six months. The participant passively attended to visual stimuli with the same stimulus presented within each session. We demonstrate that, the specific scanning day can be predicted from the brain responses in simple passive viewing paradigm, suggesting continuous temporal changes in neural activity over long time scales. However, information from one scanning day could be used to robustly decode the animacy of objects on a different scanning day, and importantly, decoding accuracy did not suffer with i...

Tourette syndrome has been linked to reduced GABAergic inhibition, so called neural disinhibition, in the dorsal striatum. Dorsal-striatal neural disinhibition in animal models, caused by local microinfusion of GABA-A-receptor antagonists, produces striatal local field potential (LFP) spike-wave discharges and tic-like movements resembling motor tics. Here, we characterized further the neuro-behavioral impact of striatal disinhibition, by unilateral picrotoxin infusion into the anterior dorsal striatum, in adult male Lister hooded rats. In vivo electrophysiology under anesthesia revealed enhanced neuronal burst firing in the striatum, alongside spike-wave LFP discharges. In freely moving rats, striatal picrotoxin reliably induced tic-like movements, which mainly involved lifting of the contralateral forelimb and concomitant rotational movements of head and torso, as well as occasional rotations of the whole body around its long axis. Prepulse inhibition (PPI) of the acoustic startle response and startle we...

Cocaine produces widely recognized rewarding effects, but also produces aversive effects that occur several minutes after rewarding effects dissipate. Prior work shows these aversive effects are particularly strong in some animals, in whom they produce conditioned avoidance effects that reduce overall cocaine-seeking. The sources of these individual variations are largely unknown, but we found evidence for contributions from heritable influences. Using outbred male and female Sprague-Dawley (SD) and Heterogeneous Stock (HS) rats, we found that offspring of individuals expressing higher versus lower levels of conditioned avoidance to cocaine on a runway operant task are themselves higher or lower in this trait. These results did not differ between sexes, and are consistent with a heritable influence driving conditioned avoidance of cocaine, which could either be genetic or non-genetic. Runway latency to obtain cocaine also differed markedly between seven inbred rat strains (tested in males only), again cons...