-
International Journal of Molecular... Jan 2023Over the past few decades, research at the molecular level has focused on the part of the genome that does not encode protein sequences. Since the discovery of...
Over the past few decades, research at the molecular level has focused on the part of the genome that does not encode protein sequences. Since the discovery of transcriptional evidence from the hitherto considered 'junk' DNA, this region of the genome, which is currently termed dark DNA, is constantly gaining interest. The term borrows an analogy from the corresponding eminent fields of dark matter and dark energy in physics and cosmology. In fact, an increasing number of attempts are being made to enhance the current understanding of the non‑coding RNA (ncRNA) transcripts produced by such regions. Although the base‑pair length and gene number appear to be very diverse between species, it appears that the amount of the non‑coding regions of the genome of an organism is a sign of evolutional superiority. ncRNA molecules are able to orchestrate the expression of genetic information in the most complex, rapid and reversible manner, participating in almost every major biological process. A prime example of such a process is the maintenance of homeostasis, the internal physiological balance, despite internal and external stressful stimuli. These molecules have been shown to be excellent regulators of gene expression, with marked spatiotemporal specificity, rendering them ideal tools for regulating stress responses. Herein, an attempt is made to extract and fuse information from a repertoire of studies, which have demonstrated that the expression of a number of these molecules was modified following exposure to acute and chronic stress, as well as in patients with anxiety disorders and their respective animal models. All in all, ncRNAs have the potential to be used either as biomarkers or as therapeutic targets for disorders resulting from the loss of equilibrium, the disruption of homeostasis and the destabilization of the hypothalamic‑pituitary‑adrenal axis.
Topics: Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; DNA
PubMed: 36484387
DOI: 10.3892/ijmm.2022.5211 -
Nature Communications Oct 2022The lateral septum (LS) has been implicated in the regulation of locomotion. Nevertheless, the neurons synchronizing LS activity with the brain's clock in the...
The lateral septum (LS) has been implicated in the regulation of locomotion. Nevertheless, the neurons synchronizing LS activity with the brain's clock in the suprachiasmatic nucleus (SCN) remain unknown. By interrogating the molecular, anatomical and physiological heterogeneity of dopamine neurons of the periventricular nucleus (PeVN; A14 catecholaminergic group), we find that Th/Dat1 cells from its anterior subdivision innervate the LS in mice. These dopamine neurons receive dense neuropeptidergic innervation from the SCN. Reciprocal viral tracing in combination with optogenetic stimulation ex vivo identified somatostatin-containing neurons in the LS as preferred synaptic targets of extrahypothalamic A14 efferents. In vivo chemogenetic manipulation of anterior A14 neurons impacted locomotion. Moreover, chemogenetic inhibition of dopamine output from the anterior PeVN normalized amphetamine-induced hyperlocomotion, particularly during sedentary periods. Cumulatively, our findings identify a hypothalamic locus for the diurnal control of locomotion and pinpoint a midbrain-independent cellular target of psychostimulants.
Topics: Animals; Dopamine; Hypothalamus; Mice; Neurons; Somatostatin; Suprachiasmatic Nucleus
PubMed: 36209152
DOI: 10.1038/s41467-022-33584-3 -
Cells Mar 2023The world is increasingly aging, and there is an urgent need to find a safe and effective way to delay the aging of the body. It is well known that the endocrine glands... (Review)
Review
The world is increasingly aging, and there is an urgent need to find a safe and effective way to delay the aging of the body. It is well known that the endocrine glands are one of the most important organs in the context of aging. Failure of the endocrine glands lead to an abnormal hormonal environment, which in turn leads to many age-related diseases. The aging of endocrine glands is closely linked to oxidative stress, cellular autophagy, genetic damage, and hormone secretion. The first endocrine organ to undergo aging is the pineal gland, at around 6 years old. This is followed in order by the hypothalamus, pituitary gland, adrenal glands, gonads, pancreatic islets, and thyroid gland. This paper summarises the endocrine gland aging-related genes and pathways by bioinformatics analysis. In addition, it systematically summarises the changes in the structure and function of aging endocrine glands as well as the mechanisms of aging. This study will advance research in the field of aging and help in the intervention of age-related diseases.
Topics: Endocrine Glands; Pituitary Gland; Gonads; Hypothalamus
PubMed: 37048056
DOI: 10.3390/cells12070982 -
WIREs Mechanisms of Disease Jul 2021The circadian timing system comprises a network of time-keeping clocks distributed across a living host whose responsibility is to allocate resources and distribute... (Review)
Review
The circadian timing system comprises a network of time-keeping clocks distributed across a living host whose responsibility is to allocate resources and distribute functions temporally to optimize fitness. The molecular structures generating these rhythms have evolved to accommodate the rotation of the earth in an attempt to primarily match the light/dark periods during the 24-hr day. To maintain synchrony of timing across and within tissues, information from the central clock, located in the suprachiasmatic nucleus, is conveyed using systemic signals. Leading among those signals are endocrine hormones, and while the hypothalamic-pituitary-adrenal axis through the release of glucocorticoids is a major pacesetter. Interestingly, the fundamental units at the molecular and physiological scales that generate local and systemic signals share critical structural properties. These properties enable time-keeping systems to generate rhythmic signals and allow them to adopt specific properties as they interact with each other and the external environment. The purpose of this review is to provide a broad overview of these structures, discuss their functional characteristics, and describe some of their fundamental properties as these related to health and disease. This article is categorized under: Immune System Diseases > Computational Models Immune System Diseases > Biomedical Engineering.
Topics: Circadian Rhythm; Glucocorticoids; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Suprachiasmatic Nucleus
PubMed: 33438348
DOI: 10.1002/wsbm.1518 -
Nature Communications Nov 2023In the mammalian visual system, the ventral lateral geniculate nucleus (vLGN) of the thalamus receives salient visual input from the retina and sends prominent GABAergic...
In the mammalian visual system, the ventral lateral geniculate nucleus (vLGN) of the thalamus receives salient visual input from the retina and sends prominent GABAergic axons to the superior colliculus (SC). However, whether and how vLGN contributes to fundamental visual information processing remains largely unclear. Here, we report in mice that vLGN facilitates visually-guided approaching behavior mediated by the lateral SC and enhances the sensitivity of visual object detection. This can be attributed to the extremely broad spatial integration of vLGN neurons, as reflected in their much lower preferred spatial frequencies and broader spatial receptive fields than SC neurons. Through GABAergic thalamocollicular projections, vLGN specifically exerts prominent surround suppression of visuospatial processing in SC, leading to a fine tuning of SC preferences to higher spatial frequencies and smaller objects in a context-dependent manner. Thus, as an essential component of the central visual processing pathway, vLGN serves to refine and contextually modulate visuospatial processing in SC-mediated visuomotor behaviors via visually-driven long-range feedforward inhibition.
Topics: Mice; Animals; Geniculate Bodies; Neurons; Thalamus; Visual Pathways; Superior Colliculi; Mammals
PubMed: 37949869
DOI: 10.1038/s41467-023-43147-9 -
Current Biology : CB Feb 2022Animals exhibit species-specific behaviors before transitioning from wake to sleep. A new study characterizes pre-sleep behaviors in mice and shows that these behaviors...
Animals exhibit species-specific behaviors before transitioning from wake to sleep. A new study characterizes pre-sleep behaviors in mice and shows that these behaviors are regulated, at least in part, by neurons in the lateral hypothalamus.
Topics: Animals; Hypothalamic Area, Lateral; Hypothalamus; Mice; Neurons; Sleep
PubMed: 35231408
DOI: 10.1016/j.cub.2022.01.009 -
The Journal of Neuroscience : the... Nov 2023In primary gustatory cortex (GC), a subregion of the insular cortex, neurons show anticipatory activity, encode taste identity and palatability, and their activity is...
In primary gustatory cortex (GC), a subregion of the insular cortex, neurons show anticipatory activity, encode taste identity and palatability, and their activity is related to decision-making. Inactivation of the gustatory thalamus, the parvicellular region of the ventral posteromedial thalamic nucleus (VPMpc), dramatically reduces GC taste responses, consistent with the hypothesis that VPMpc-GC projections carry taste information. Recordings in awake rodents reported that taste-responsive neurons can be found across GC, without segregated spatial mapping, raising the possibility that projections from the taste thalamus may activate GC broadly. In addition, we have shown that cortical inhibition modulates the integration of thalamic and limbic inputs, revealing a potential role for GABA transmission in gating sensory information to GC. Despite this wealth of information at the system level, the synaptic organization of the VPMpc-GC circuit has not been investigated. Here, we used optogenetic activation of VPMpc afferents to GC in acute slice preparations from rats of both sexes to investigate the synaptic properties and organization of VPMpc afferents in GC and their modulation by cortical inhibition. We hypothesized that VPMpc-GC synapses are distributed across GC, but show laminar- and cell-specific properties, conferring computationally flexibility to how taste information is processed. We also found that VPMpc-GC synaptic responses are strongly modulated by the activity regimen of VPMpc afferents, as well as by cortical inhibition activating GABA and GABA receptors onto VPMpc terminals. These results provide a novel insight into the complex features of thalamocortical circuits for taste processing. We report that the input from the primary taste thalamus to the primary gustatory cortex (GC) shows distinct properties compared with primary thalamocortical synapses onto other sensory areas. Ventral posteromedial thalamic nucleus afferents in GC make synapses with excitatory neurons distributed across all cortical layers and display frequency-dependent short-term plasticity to repetitive stimulation; thus, they do not fit the classic distinction between drivers and modulators typical of other sensory thalamocortical circuits. Thalamocortical activation of GC is gated by cortical inhibition, providing local corticothalamic feedback via presynaptic ionotropic and metabotropic GABA receptors. The connectivity and inhibitory control of thalamocortical synapses in GC highlight unique features of the thalamocortical circuit for taste.
Topics: Male; Female; Rats; Animals; Insular Cortex; Thalamus; Ventral Thalamic Nuclei; Neurons; gamma-Aminobutyric Acid; Cerebral Cortex
PubMed: 37704374
DOI: 10.1523/JNEUROSCI.2255-22.2023 -
Neuroscience and Biobehavioral Reviews Dec 2020Two thalamic sites are of especial significance for understanding hippocampal - diencephalic interactions: the anterior thalamic nuclei and nucleus reuniens. Both nuclei... (Review)
Review
Two thalamic sites are of especial significance for understanding hippocampal - diencephalic interactions: the anterior thalamic nuclei and nucleus reuniens. Both nuclei have dense, direct interconnections with the hippocampal formation, and both are directly connected with many of the same cortical and subcortical areas. These two thalamic sites also contain neurons responsive to spatial stimuli while lesions within these two same areas can disrupt spatial learning tasks that are hippocampal dependent. Despite these many similarities, closer analysis reveals important differences in the details of their connectivity and the behavioural impact of lesions in these two thalamic sites. These nuclei play qualitatively different roles that largely reflect the contrasting relative importance of their medial frontal cortex interactions (nucleus reuniens) compared with their retrosplenial, cingulate, and mammillary body interactions (anterior thalamic nuclei). While the anterior thalamic nuclei are critical for multiple aspects of hippocampal spatial encoding and performance, nucleus reuniens contributes, as required, to aid cognitive control and help select correct from competing memories.
Topics: Anterior Thalamic Nuclei; Hippocampus; Humans; Mammillary Bodies; Midline Thalamic Nuclei; Neural Pathways; Neurons
PubMed: 33069688
DOI: 10.1016/j.neubiorev.2020.10.006 -
Epilepsy Research May 2022There is no doubt on the participation of the thalamus in the various types of genetic generalized epilepsies as evidenced by multiple non-invasive imaging studies in... (Review)
Review
There is no doubt on the participation of the thalamus in the various types of genetic generalized epilepsies as evidenced by multiple non-invasive imaging studies in humans as well as invasive studies in animal models of GGE. Based on human and mostly animal data gathered in early 2000 a so called 'three compartment model' on seizure generation was proposed conceptualizing the existence of a hyperexcitable cortical seizure onset zone providing excitation to relay cells of the relay thalamus and the inhibitory reticular thalamic nucleus (RTn). The interplay of corticothalamic excitation and feedforward inhibition via RTn is supposed to entrain thalamic relay neurons into synchronous, oscillatory activity for SWD sustainment. With the emergence of more fine-tuned experimental techniques and analyses, however, it becomes apparent that this model is too simplistic as the thalamus cannot be regarded as unity. Rather, different thalamic nuclei, being integrated in different thalamocortical and other subcortical subloops, need to be differentiated, which take over different functions for seizure generation, generalization and maintenance. Moreover, these networks are not necessarily the same for different classes of patients with GGE and can even be antagonistic between seizure types. This review will summarize data concerning different nuclei and their participation in GGE in order to extend this model and create a more detailed concept on seizure generation, generalization and maintenance.
Topics: Animals; Epilepsy, Absence; Epilepsy, Generalized; Humans; Seizures; Thalamic Nuclei; Thalamus
PubMed: 35427989
DOI: 10.1016/j.eplepsyres.2022.106918 -
Brain Structure & Function Jun 2023The primate thalamus has been subdivided into multiple nuclei and nuclear groups based on cytoarchitectonic, myeloarchitectonic, connectional, histochemical, and... (Review)
Review
The primate thalamus has been subdivided into multiple nuclei and nuclear groups based on cytoarchitectonic, myeloarchitectonic, connectional, histochemical, and genoarchitectonic differences. Regarding parcellation and terminology, two main schools prevailed in the twentieth century: the German and the Anglo-American Schools, which proposed rather different schemes. The German parcellation and terminology has been mostly used for the human thalamus in neurosurgery atlases; the Anglo-American parcellation and terminology is the most used in experimental research on the primate thalamus. In this article, we review the historical development of terminological and parcellation schemes for the primate thalamus over the last 200 years. We trace the technological innovations and conceptual advances in thalamic research that underlie each parcellation, from the use of magnifying lenses to contemporary genoarchitectonic stains during ontogeny. We also discuss the advantages, disadvantages, and practical use of each parcellation.
Topics: Animals; Humans; Thalamic Nuclei; Thalamus; Primates; Staining and Labeling; Cell Nucleus
PubMed: 36622414
DOI: 10.1007/s00429-022-02598-4