Biology subjects

Peterfi, Z.

Publications and source records attributed to Peterfi, Z..

4 recordsLinked to original sources

bioRxiv2025

Comparative analysis of naked mole-rat thermogenesis and its potential to maintain euthermia in response to cold

The naked mole-rat (NMR) is a subterranean rodent known for its unique thermal biology, exceptional longevity and resistance to cancer and hypoxia. However, its thermal biology remains controversial, with various reports describing NMRs as poikilotherms, heterotherms, mesotherms or partial homeotherms. Here, we investigated whether the thermogenic potential of NMR brown adipose tissue and its UCP1 differ from those in mice and whether the lack of thermal insulation causes extreme changes in NMR body temperature upon cold exposure. Through longitudinal molecular, thermal, metabolic, and behavioral measurements, we found that NMRs initiated non-shivering thermogenesis and elevated body temperature but could not sustain it due to excessive heat loss and limits to substrate availability. Our results suggest that NMRs represent a unique thermoregulatory category that doesnt fit neatly into traditional classifications. In vitro and in vivo experiments showed that the NMR UCP1 is functional and can be activated and inhibited as expected for most other mammals. We further demonstrated that artificial insulation can partially restore thermoregulatory capabilities in NMRs. This study employs an advanced methodology to characterize the thermal biology of NMRs and helps resolve a long-standing controversy in the field. Significance StatementThis study provides critical insights into the thermal biology of naked mole-rats (NMRs), resolving long-standing controversies regarding their thermoregulatory strategies. We highlight the unique adaptations and limitations of NMR physiology by demonstrating that NMRs possess functional non-shivering thermogenesis and UCP1 but fail to maintain homeothermy due to excessive heat loss. Our findings suggest that artificial insulation can partially restore their thermoregulatory capabilities, offering a new perspective on the evolutionary and ecological significance of fur loss in NMRs. This research advances our understanding of mammalian thermal biology and presents an updated model for NMRs, bridging gaps between previous conflicting reports.

physiology↗

bioRxiv2023

Diversity and connectivity of principal neurons in the lateral and basal nuclei of the mouse amygdala

The basolateral amygdala is a non-layered cortical structure playing a role in various cognitive processes. Despite many studies focusing on local information processing within the circuits of the basolateral amygdala, the characteristics of excitatory principal neurons (PNs) are still not fully revealed. Here, we combined neuroanatomical, electrophysiological, and tracing techniques to determine the single-cell features, dendritic and axonal projections of PNs within the lateral (LA) and basal amygdala (BA). Using a mouse reporter line, we found that cholecystokinin (CCK) expression defines two spatially and functionally segregated groups of PNs both in the LA and BA. PNs in CCK-positive (CCK+) areas of the LA (LAa) had small somata and short dendrites which matched their single-cell electrophysiological properties. PNs in CCK-negative (CCK-) areas of the LA (LAp) and all BA had similarly ramified dendrites and single-cell features with some differences. Importantly, the dendritic arbors of PNs were restricted to the subnuclei defined by CCK expression, which corresponded to various extra-amygdalar afferents indicating specific inputs on distinct PN groups. Axonal arborization patterns of PNs within the basolateral amygdala and surrounding areas showed consistency to their soma location. For instance, BA PNs that projected to the medial prefrontal cortex but not to the lateral nucleus of the central amygdala were present in CCK+ areas. In contrast, those BA PNs that projected to the lateral part of the central nucleus were found in the subnucleus lacking CCK. Our study revealed that the basolateral amygdala is composed of functionally different subnuclei with specific inputs and outputs. This structural arrangement may empower the LA and BA to flexibly channel processed information toward their downstream regions, which can be a key requirement for diverse amygdala functions in cognitive operation.

neuroscience↗

bioRxiv2022

Morpho-electric and transcriptomic divergence of the layer 1 interneuron repertoire in human versus mouse neocortex

Neocortical layer 1 (L1) is a site of convergence between pyramidal neuron dendrites and feedback axons where local inhibitory signaling can profoundly shape cortical processing. Evolutionary expansion of human neocortex is marked by distinctive pyramidal neuron types with extensive branching in L1, but whether L1 interneurons are similarly diverse is underexplored. Using patch-seq recordings from human neurosurgically resected tissues, we identified four transcriptomically defined subclasses, unique subtypes within those subclasses and additional types with no mouse L1 homologue. Compared with mouse, human subclasses were more strongly distinct from each other across all modalities. Accompanied by higher neuron density and more variable cell sizes compared with mouse, these findings suggest L1 is an evolutionary hotspot, reflecting the increasing demands of regulating the expanding human neocortical circuit. One Sentence SummaryUsing transcriptomics and morpho-electric analyses, we describe innovations in human neocortical layer 1 interneurons.

neuroscience↗

bioRxiv2018

Organ-specific translation elongation rates measured by in vivo ribosome profiling

Protein synthesis and degradation are intricate biological processes involving more than a hundred proteins operating in a highly orches-trated fashion. Despite the progress, few options are available to access translation in live animals as the increase in animals complexity limits the repertoire of experimental tools that could be applied to observe and manipulate processes within animals body, organs, and individual cells. It this study, we developed a labeling-free method for measuring organ- and cell-type specific translation elongation rates. It is based on a time-resolved delivery of translation initiation and elongation inhibitors in live animals followed by ribosome profiling. It also reports translation initiation sites in an organ-specific manner. Using this method, we found that the elongation rates differ among mouse organs and determined them to be 6.8, 5.2, and 4.4 amino acids per sec for liver, kidney, and skeletal muscle, respectively.\n\nSignificanceProtein synthesis is a vital biological process. Modern methods of genome editing enable generation of sophisticated animal models to study the regulation of protein synthesis in health end disease. However, the methods that could track various steps of translation at a gene level resolution in vivo are lacking, particularly in complex vertebrates, such as mice and rats. Here, we measured the translation elongation rate in several organs by delivering inhibitors specific to certain phases of translation directly through the mouse bloodstream. This study lays out a path for interrogating translation in animals in response to various genetic and dietary interventions.

molecular biology↗