Exposure of the fetus to alcohol (ethanol) via maternal consumption during pregnancy can result in fetal alcohol spectrum disorders (FASD), hallmarked by long-term physical, behavioral, and intellectual abnormalities. In our preclinical mouse model of FASD, prenatal ethanol exposure disrupts tangential migration of corticopetal GABAergic interneurons in the embryonic medial prefrontal cortex (mPFC). We postulated that ethanol perturbed the normal pattern of tangential migration via enhancing GABAA receptor-mediated membrane depolarization that prevails during embryonic development in GABAergic cortical interneurons. However, beyond this, our understanding of the underlying mechanisms is incomplete. Here, we tested the hypothesis that the ethanol-enhanced depolarization triggers downstream an increase in high-voltage activated nifedipine-sensitive L-type calcium channel (LTCC) activity, and provide evidence implicating calcium dynamics in the signaling scheme underlying the migration of embryonic GABAergic ...

Acquiring new memories is a multi-stage process. Numerous studies have convincingly demonstrated that initially acquired memories are labile, and only stabilized by later consolidation processes. These multiple phases of memory formation are known to involve modification of both cellular excitability and synaptic connectivity, which in turn change neuronal activity at both the single neuron and ensemble levels. However, the specific mapping between the known phases of memory and the changes in neuronal activity at different organizational levels – the single-neuron, population representations, and ensemble state dynamics – remains unknown. Here we address this issue in the context of conditioned taste aversion learning by continuously tracking gustatory cortex (GC) neuronal taste responses in alert male and female rats during the 24 hours following a taste-malaise pairing. We found that the progression of activity changes depends on the neuronal organizational level: whereas the population response changed...

Peripheral nerves are divided into multiple branches leading to divergent synaptic targets. This poses a remarkable challenge for regenerating axons as they select their original trajectory at nerve branch-points. Despite implications for functional regeneration, the molecular mechanisms underlying target selectivity are not well characterized. Danio Rerio (zebrafish) motor nerves are composed of a ventral and a dorsal branch that diverge at a choice-point, and we have previously shown that regenerating axons faithfully select their original branch and targets. Here we identify Robo2 as a key regulator of target-selective regeneration (sex of experimental subjects unknown). We demonstrate that Robo2 function in regenerating axons is required and sufficient to drive target-selective regeneration, and that Robo2 acts in response to glia located precisely where regenerating axons select the branch-specific trajectory to prevent and correct axonal errors. Combined our results reveal a glia derived mechanism th...

Aging is often associated with cognitive decline and recurrent cellular and molecular impairments. While life-long caloric restriction (CR) may delay age-related cognitive deterioration as well as the onset of neurological disease, recent studies suggest that late-onset, short-term intermittent fasting (IF), may show comparable beneficial effects as those of life-long CR to improve brain health. We used a new optogenetic aging model to study the effects of late-onset (>18 months), short-term (4-6 weeks) IF on age-related changes in GABAergic synaptic transmission, intracellular calcium (Ca2+) buffering and cognitive status. We utilized male mice from a bacterial artificial chromosome (BAC) transgenic mouse line with stable expression of the channelrhodopsin-2 (ChR2) variant H134R [VGAT-ChR2(H134R)-EYFP] in a reduced synaptic preparation that allows for specific optogenetic light stimulation on GABAergic synaptic terminals across aging. We performed quantal analysis using the method of failures in this mode...

Neurotoxic HIV-1 viral proteins contribute to the development of HIV-associated neurocognitive disorder (HAND), the prevalence of which remains high (30–50%) with no effective treatment available. Estrogen is a known neuroprotective agent; however, the diverse mechanisms of estrogen action on the different types of estrogen receptors is not completely understood. In this study, we determined the extent to which and mechanisms by which 17α-estradiol (17αE2), a natural less-feminizing estrogen, offers neuroprotection against HIV-1 gp120-induced neuronal injury. Endolysosomes are important for neuronal function, and endolysosomal dysfunction contributes to HAND and other neurodegenerative disorders. In hippocampal neurons, estrogen receptor α (ERα) is localized to endolysosomes and 17αE2 acidifies endolysosomes. ERα knockdown or overexpressing an ERα mutant that is deficient in endolysosome localization prevents 17αE2-induced endolysosome acidification. Furthermore, 17αE2-induced increases in dendritic spine ...

The cerebral cortex, basal ganglia and motor thalamus form circuits important for purposeful movement. In Parkinsonism, basal ganglia neurons often exhibit dysrhythmic activity during, and with respect to, the slow (∼1 Hz) and beta-band (15-30 Hz) oscillations that emerge in cortex in a brain state-dependent manner. There remains, however, a pressing need to elucidate the extent to which motor thalamus activity becomes similarly dysrhythmic after dopamine depletion relevant to Parkinsonism. To address this, we recorded single-neuron and ensemble outputs in the basal ganglia-recipient zone (BZ) and cerebellar-recipient zone (CZ) of motor thalamus in anesthetized male dopamine-intact rats and 6-OHDA-lesioned rats during two brain states, respectively defined by cortical slow-wave activity and activation. Two forms of thalamic input zone-selective dysrhythmia manifested after dopamine depletion: (1) BZ neurons, but not CZ neurons, exhibited abnormal phase-shifted firing with respect to cortical slow oscillati...

Invited reviewers are asked to identify colleagues who assisted with review. JNeurosci would like to acknowledge the hard work of these collaborating reviewers and thank them for their service to the journal. Andrin Abegg Julia Abitbol Tobias Ackels Elie Adam Kadidia Adula Blanca Aldana Mor