Zoology

Summary

Zoology (zoʊˈɒlədʒi) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one of the primary branches of biology. The term is derived from Ancient Greek ζῷον, ('animal'), and λόγος, logos ('knowledge', 'study'). Although humans have always been interested in the natural history of the animals they saw around them, and used this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle. He viewed animals as living organisms, studied their structure and development, and considered their adaptations to their surroundings and the function of their parts. Modern zoology has its origins during the Renaissance and early modern period, with Carl Linnaeus, Antonie van Leeuwenhoek, Robert Hooke, Charles Darwin, Gregor Mendel and many others. The study of animals has largely moved on to deal with form and function, adaptations, relationships between groups, behaviour and ecology. Zoology has increasingly been subdivided into disciplines such as classification, physiology, biochemistry and evolution. With the discovery of the structure of DNA by Francis Crick and James Watson in 1953, the realm of molecular biology opened up, leading to advances in cell biology, developmental biology and molecular genetics. History of zoology through 1859 and History of zoology (1859–present) The history of zoology traces the study of the animal kingdom from ancient to modern times. Prehistoric people needed to study the animals and plants in their environment in order to exploit them and survive. There are cave paintings, engravings and sculptures in France dating back 15,000 years showing bison, horses and deer in carefully rendered detail. Similar images from other parts of the world illustrated mostly the animals hunted for food, but also the savage animals.

Categories

Official source

https://en.wikipedia.org/wiki/Zoology

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related categories (265)

Related concepts (176)

Related courses (1)

Related lectures (27)

Related MOOCs (6)

Related people (26)

Related publications (53)

Understanding how neural circuits remodel and adapt to animal behavior is a central theme in the field of Neuroscience. One strategy to reach this goal is to repeatedly record the same animal's neural circuits and observe how they adapt when facing different challenges. Research has primarily focused on identifying neural circuits and connectivity maps within the brains of model organisms. Nevertheless, it has become evident that functional recordings are essential to have a complete understanding of how neural circuits generate behaviors. Numerous techniques have been introduced to record activity from brain circuits in model animals spanning from monkeys to insects. However, imaging the spinal cord in mammals or the ventral nerve cord in insects remains an open challenge due to the complexity of obtaining optical access without impacting the animal's behavior and damaging neural tissues. As a result, we have very limited information on how neural circuits in the spinal cord generate behaviors and how they adapt to different experiences such as injury or aging. Drosophila is a perfect model organism for carrying out this line of research thanks to its small size, genetically tractable nervous system, and behavioral diversity. The results are relevant to human physiology and behavior as many mechanisms have homologs in mammals. What is missing is a technological advancement that allows recording of behavior, structural changes in the circuits, and spatiotemporal dynamics of neural activity on the same animal.This thesis addresses this gap and introduces two novel methods for in vivo functional recordings of the fly's ventral nerve cord (VNC). The first one gains short-term access to the fly's VNC using a novel dissection preparation. The second one enables long-term functional recordings of the fly's VNC thanks to a toolkit combining four microengineered devices: a surgical arm, a V-shape implant, an optically transparent and numbered window and a remounting stage. The toolkit is suitable for both male and female flies and provides optical access to the VNC for at least one month. Additionally, the long-term toolkit does not impact flies' behaviors compared to intact flies and can be used to image both sparse and large populations of neural activity in flies' cervical connective and VNC. The toolkit was tested in two proof-of-concept (POC) applications. In the first POC, the toolkit monitored the degradation of sensory neurons in the VNC over weeks following limb amputation. In the second POC, the toolkit monitored global changes in neural dynamics following ingestion of a high-concentration caffeine solution. In conclusion, this thesis introduces new techniques for functional recordings of the fly's cervical connective and VNC over short and long time scales. They enable optical access to the fly's cervical connective that can be leveraged to study the content of information transmitted between the brain and the VNC while the fly is behaving. The two POCs demonstrate that the novel technology is ideally suited for long-term experiments and could be applied to a wide range of studies. For instance, the toolkit could be used to investigate how behaviors are encoded in the fly's VNC and how they adapt over time to experiences such as disease, aging, drug intake and learning.

EPFL2022

Genetic selection for low glucocorticoid responsiveness recapitulates PTSD-related phenotypes: a behavioral, neuroimaging and sleep-physiology study

Silvia Monari

Humans show inter-individual differences in vulnerability to develop post-traumatic stress disorder (PTSD) following exposure to trauma. Several critical biobehavioral features have been consistently described in PTSD patients, including blunted cortisol levels, smaller hippocampal size, sleep disturbances. However, because of the delay between trauma exposure and the onset of symptoms characteristic of PTSD, only a few longitudinal studies have tried to dissect whether these features constitute pre-trauma risk factors or consequences of the trauma. Enormous effort in animal and human studies has been dedicated to understanding mechanisms of conditioned fear and fear extinction, processes that are at the core of PTSD. However, the same progress has not been translated into psychiatric practice for PTSD. Deepening our understanding of the contribution of key factors to PTSD-related alterations can serve to develop effective treatments.In particular, with regard to low cortisol levels in PTSD pathophysiology, a causative role for blunted glucocorticoid responsiveness in PTSD has not been demonstrated yet.Here, we have addressed this question in lines of Wistar rats genetically-selected for their differential habituation of glucocorticoid responses to stress (LOW-, INTER-, HIGH-CORT Responder rats) and focused on fear extinction, a hallmark of PTSD symptomology, as one of the key features. As a first step, we looked whether divergent trajectories of glucocorticoid responsiveness were associated with brain volume abnormalities, prompted by the influential role of glucocorticoid in brain development. Notably, rats with low or high corticosterone responsiveness exhibit smaller hippocampi, regardless of trauma exposure, compared to rats with normative corticosterone levels. Similarly, the distribution of corticosteroid receptors in the hippocampus presented similarities between the LOW-CR and the HIGH-CR rats with higher mineralocorticoid receptors (MR) and less glucocorticoid receptors (GR). Although LOW- and HIGH-CR rats displayed a similar hippocampal profile at the structural and molecular levels, only LOW-CR male rats exhibited strong deficits in extinction consolidation compared to rats with 'normative' glucocorticoid responses (INTER-CR rats), and showed higher fear response both at few days and at several weeks after trauma exposure. We next tested the causal involvement of corticosterone in the fear extinction consolidation, and found that post-extinction corticosterone treatment markedly prevented the deficits in extinction memory and attenuated fear relapse. In addition, pharmacological inhibition of corticosterone levels during extinction memory consolidation, but not during training, in the INTER-CR rats led to extinction deficits at retrieval one day later. These results indicate that blunted corticosterone levels contribute to confer major vulnerability than having a small hippocampus, and that consolidation processes following extinction are mainly affected by low corticosterone levels.It is well known that glucocorticoids play an important role in memory consolidation processes and that sleep disturbances are a diagnostic criterion of PTSD. Therefore, we investigated in greater detail the sleep architecture in undisturbed condition and during the consolidation period of the extinction phase, which is known to be supported by sleep-dependent processes. In polysomnographic recordings, we found that rats with blunted corticos

EPFL2022

Most genes in higher eukaryotes express isoforms with distinct 3' untranslated regions (3' UTRs), generated by alternative polyadenylation (APA). Since 3' UTRs are predominant locations of post-transcriptional regulation, APA can render such programs conditional, and can also alter protein sequences via alternative last exon (ALE) isoforms. We previously used 3'-sequencing from diverse Drosophila samples to define multiple tissue-specific APA landscapes. Here, we exploit comprehensive single nucleus RNA-sequencing data (Fly Cell Atlas) to elucidate cell-type expression of 3' UTRs across >250 adult Drosophila cell types. We reveal the cellular bases of multiple tissue-specific APA/ALE programs, such as 3' UTR lengthening in differentiated neurons and 3' UTR shortening in spermatocytes and spermatids. We trace dynamic 3' UTR patterns across cell lineages, including in the male germline, and discover new APA patterns in the intestinal stem cell lineage. Finally, we correlate expression of RNA binding proteins (RBPs), miRNAs and global levels of cleavage and polyadenylation (CPA) factors in several cell types that exhibit characteristic APA landscapes, yielding candidate regulators of transcriptome complexity. These analyses provide a comprehensive foundation for future investigations of mechanisms and biological impacts of alternative 3' isoforms across the major cell types of this widely-studied model organism.

NATURE PORTFOLIO2022