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Biology subjects

Zala, D.

Publications and source records attributed to Zala, D..

4 recordsLinked to original sources

Sex-dependent effects of a gestational ketogenic diet on offspring birth and lifespan

Low-carbohydrate, high-fat ketogenic diets (KDs) are used to treat drug-resistant epilepsy, and other potential benefits for treating neurological disorders, metabolic syndrome, and cancer are being explored. In addition to these and other medical applications, KDs have also become popular for rapid weight-loss and enhancing athletic performance. However, the effects of exposing developing offspring to KDs during pregnancy (gestational KD) are poorly understood, and especially their long-term health consequences. In this study, we investigated the effects of a partial gestational KD during the second half of pregnancy in mice and assessed the consequences on the offspring over their entire lifespan compared to offspring exposed to a control diet. We found that a gestational KD significantly reduced dams litter size and litter mass and altered the sex ratio at birth, reducing the proportion of female offspring, which also had lower body mass early in their life. In contrast, male offspring exposed to a gestational KD suffered a significantly reduced lifespan and a late-onset increase in body mass. We found no evidence that our KD diet influenced adult offspring behavior (locomotion, anxiety, depression, circadian rhythms, food and water consumption) or reproduction. These findings highlight the potential of even a partial maternal exposure to a KD to have surprisingly detrimental effects on offspring health and longevity, and thus raising concerns about its use during pregnancy.

physiology↗

The cortico-striatal circuit regulates sensorimotor gating via Disc1/Huntingtin-mediated Bdnf transport

Sensorimotor information processing that underlies normal cognitive and behavioral traits is dysregulated across a subset of neurological and psychiatric disorders. The cross-disease deficit in sensorimotor gating poses a unique opportunity to integrate hierarchical findings at molecular, cellular, through circuitry levels to obtain an in-depth mechanistic understanding of this process that contributes to brain physiology and pathophysiology beyond categorical segmentation of brain disorders. Based on circuitry recording with wild-type mice, we demonstrated that the cortico-striatal projection mediates sensorimotor gating responses during prepulse inhibition (PPI) task. We also found that these circuitry responses were disrupted in Disc1 locus-impairment (LI) mice, a model representing neuropsychiatric conditions. Thus, we hypothesized that Disc1-mediated molecular and cellular machinery along the cortico-striatal circuit may regulate sensorimotor gating. Anatomical and biochemical analyses of Disc1-LI mice revealed attenuated Bdnf transport along the cortico-striatal circuit. Pharmacologically augmenting Bdnf transport by chronic lithium administration, in part via Ser-421 phosphorylation of Huntingtin (Htt) and its integration into the motor machinery, restored the striatal Bdnf levels and PPI deficits in Disc1-LI mice, suggesting that the Bdnf transport attenuation mechanistically underlies the circuitry and behavioral deficits. These results also shed light on a novel mechanism and utility of lithium that is currently used as a major mood stabilizer in clinical settings. Collectively, the present study illustrates integrative biological mechanisms for sensorimotor gating, underscoring the cross-disease nature of this behavioral dimension and translational utility of the findings under the era of precision medicine in brain disorders.

neuroscience↗

Actomyosin-mediated nanostructural remodeling of the presynaptic vesicle pool by cannabinoids induces long-term depression

Endo- and exocannabinoids, such as the psychoactive component of marijuana, exert their effects on brain function by inducing several forms of synaptic plasticity through the modulation of presynaptic vesicle release. However, the molecular mechanisms underlying the widely expressed endocannabinoid-mediated long-term depression (eCB-LTD), are poorly understood. Here, we reveal that eCB-LTD depends on the contractile properties of the pre-synaptic actomyosin cytoskeleton. Preventing this contractility, both directly by inhibiting non-muscle myosin II NMII ATPase and indirectly by inhibiting the upstream Rho-associated kinase ROCK, abolished long-term, but not short-term forms of cannabinoid-induced functional plasticity in both inhibitory hippocampal and excitatory cortico-striatal synapses. Furthermore, using 3D superresolution microscopy, we find an actomyosin contractility-dependent redistribution of synaptic vesicle pools within the presynaptic compartment following cannabinoid receptor activation, leading to vesicle clustering and depletion from the pre-synaptic active zone. These results suggest that cannabinoid-induced functional plasticity is mediated by a nanoscale structural reorganization of the presynaptic compartment produced by actomyosin contraction. By introducing the contractile NMII as an important actin binding/structuring protein in the dynamic regulation of synaptic function, our results open new perspectives in the understanding of mechanisms of synaptic and cognitive function, marijuana intoxication and psychiatric pathogenesis.

neuroscience↗

Pharmacological modulation of AMPA receptor surface diffusion restores hippocampal synaptic plasticity and memory in Huntington’s disease

Impaired hippocampal synaptic plasticity is increasingly considered to play an important role in cognitive impairment in Huntingtons disease (HD). However, the molecular basis of synaptic plasticity defects is not fully understood. Combining live-cell nanoparticle tracking and super-resolution imaging, we show that dysregulation of AMPA receptors (AMPARs) surface diffusion represents a molecular basis underlying the aberrant hippocampal synaptic plasticity during HD. AMPARs surface diffusion is increased in various HD neuronal models, which results in the failure of AMPARs surface stabilization after long-term potentiation (LTP) stimuli. This appears to result from a defective brain-derived neurotrophic factor (BDNF) - tyrosine receptor kinase B (TrkB) - Ca2+/calmodulin-dependent protein kinase II (CaMKII) signaling pathway that impacts the interaction between the AMPAR auxiliary subunit stargazin and postsynaptic density protein 95 (PSD-95). Notably, the disturbed AMPAR surface diffusion is rescued, via BDNF signaling pathway and by the antidepressant tianeptine. Tianeptine also restores the impaired LTP and hippocampus-dependent memory as well as anxiety/depression-like behavior in different HD mouse models. We thus unveil a mechanistic framework underlying hippocampal synaptic and memory dysfunction and propose a new perspective in HD treatment by targeting AMPAR surface diffusion.

neuroscience↗