Paul.Manger@wits.ac.za 2 Highlights The organisation of four neural systems is described in the brains of three Afrotherians not previously studied These systems are organised in a similar manner to other mammals. There are features that reflect both phylogenetic and functional signals in the evolution of these neural systems. The golden mole appears to be a "hyper-cholinergic" mammal, possessing cholinergic neurons in novel regions of the brain. AbstractThe present study describes the organization of the cholinergic, catecholaminergic, serotonergic and orexinergic (hypocretinergic) neurons in the brains of the giant otter shrew, the Hottentot golden mole and the four-toed sengi, three members of the mammalian super orderAfrotheria. The aim of the present study was to investigate the possible differences in the nuclear complement of these neural systems in comparison to previous studies on other Afrotheria species and other mammalian species. Brains of the golden mole, sengi and giant otter shrew were coronally sectioned and immunohistochemically stained with antibodies against cholineacetyl-transferase, tyrosine hydroxylase, serotonin and orexin-A. The majority of nuclei revealed in the current study were similar between the species investigated, to other Afrotherian species investigated, and to other mammals, but certain differences in the nuclear complement highlighted phylogenetic interrelationships. The golden mole was seen to have cholinergic interneurons in the cerebral cortex, hippocampus, olfactory bulb and amygdala. The four-toed sengi had cholinergic neurons in both colliculi and in the cochlear nucleus, but lacked the catecholaminergic A15d group in the hypothalamus. In both the golden mole and the four-toed sengi, the locus coeruleus (A6d group) was made up of few neurons. The golden mole also exhibited an unusual foreshortening of the brain, such that a major kink in the brainstem was evident. The results of this study, framed in a phylogenetic context, appear to indicate that the golden mole and four-toed sengi share a more recent common ancestor that diverged from the tenrec lineage early in the phylogenetic history of the Afrotherians.
The nuclear organization of the cholinergic, catecholaminergic, serotonergic and orexinergic systems in the brains of three species of strepsirrhine primates is presented. We aimed to investigate the nuclear complement of these neural systems in comparison to those of simian primates, megachiropterans and other mammalian species. The brains were coronally sectioned and immunohistochemically stained with antibodies against choline acetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The nuclei identified were identical among the strepsirrhine species investigated and identical to previous reports in simian primates. Moreover, a general similarity to other mammals was found, but specific differences in the nuclear complement highlighted potential phylogenetic interrelationships. The central feature of interest was the structure of the locus coeruleus complex in the primates, where a central compactly
Nuclear organisation of some immunohistochemically identifiable neural systems in two species of the Euarchontoglires: a Lagomorph, Lepus capensis, and a Scandentia, Tupaia belangeri, Journal of Chemical Neuroanatomy (2015), http://dx.doi.org/10. 1016/j.jchemneu.2015.10.007 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A c c e p t e d M a n u s c r i p t 2 AbstractThe present study describes the organization of the nuclei of the cholinergic, catecholaminergic, serotonergic and orexinergic systems in the brains of two members of Euarchontoglires, Lepus capensis and Tupaia belangeri. The aim of the present study was to investigate the nuclear complement of these neural systems in comparison to previous studies on Euarchontoglires and generally with other mammalian species. Brains were coronally sectioned and immunohistochemically stained with antibodies against choline acetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The majority of nuclei revealed in the current study were similar between the species investigated and to mammals generally, but certain differences in the nuclear complement highlight potential phylogenetic interrelationships within the Euarchontoglires and across mammals. In the northern tree shrew the nucleus of the trapezoid body contained neurons immunoreactive to the choline acetyltransferase antibody with some of these neurons extending into the lamellae within the superior olivary nuclear complex (SON). The cholinergic nature of the neurons of this nucleus, and the extension of cholinergic neurons into the SON, has not been noted in any mammal studied to date. In addition, cholinergic neurons forming the medullary tegmental field were also present in the northern tree shrew. Regarding the catecholaminergic system, the cape hare presented with the rodent specific rostral dorsal midline medullary nucleus (C3), and the northern tree shrew lacked both the ventral and dorsal divisions of the anterior hypothalamic group (A15v and A15d). Both species were lacking the primate/megachiropteran specific compact portion of the locus coeruleus complex (A6c). The nuclei of the serotonergic and orexinergic systems of both species were similar to those seen across most Eutherian mammals. Our results lend support to the monophyly of the Glires, and more broadly suggest that the megachiropterans are more closely related to the primates than are any other members of Euarchontoglires studied to date.
Globally, there are concerns about access to healthcare and harm reduction services for people who use drugs (PWUD) during the coronavirus disease 2019 (COVID-19) pandemic. Members from the Network of Early Career Professionals working in Addiction Medicine shared their experiences of providing treatment to PWUD during the COVID-19 pandemic. Drawing on these qualitative reports, we highlight the similarities and discrepancies in access to services for PWUD in 16 countries under COVID-10 restrictions. In most countries reported here, efforts have been made to ensure continued access to services, such as mobilising opioid agonist maintenance treatment and other essential medicines to patients. However, due to travel restrictions and limited telemedicine services, several Network of Early Career Professionals working in Addiction Medicine members from lower-resourced countries experienced challenges with providing care to their patients during periods of COVID-19 lock-down. The insights provided in this commentary illustrate how the COVID-19 lock-down restrictions have impacted access to services for PWUD.
Paul.Manger@wits.ac.za 1 Highlights• Several neural systems in the brains of insectivores are described.• All species show a similar global pattern of organization.• Certain variations indicate a phylogenetic relationships between shrews and microchiropterans.• This study support the diphyletic hypothesis of bat evolution. AbstractThe organization of the cholinergic, catecholaminergic, and serotonergic neurons in the brains of five species of insectivores and the orexinergic (hypocretinergic) system in four insectivore species is presented. We aimed to investigate the nuclear complement of these neural systems in comparison to those of other mammalian species. Brains of insectivores were coronally sectioned and immunohistochemically stained with antibodies against cholineacetyltransferase, tyrosine hydroxylase, serotonin and orexin-A. The majority of nuclei were similar among the species investigated and to mammals in general, but certain differences in the nuclear complement highlighted potential phylogenetic interrelationships.In the cholinergic system, the three shrew species lacked parabigeminal and EdingerWestphal nuclei. In addition, the appearance of the laterodorsal tegmental nucleus in all insectivores revealed a mediodorsal arch. All three of these features are the same as those present in microchiropterans. The catecholaminergic system of the three shrew species lacked the A4 and A15d nuclei, as well as having an incipient A9v nucleus, again features found in microchiropteran brains. The serotonergic and orexinergic systems of the insectivores are similar to those seen across most Eutherian mammals. The analysis of similarities and differences across mammalian species indicates a potential phylogenetic relationship between the Soricidae (shrews) and the microchiropterans.
Alcohol use is a major risk factor for infectious disease and reduction of harms associated with alcohol consumption are essential during times of humanitarian crises, such as the COVID-19 pandemic. As a network of early career professionals working in the area of addiction medicine, we provide our views with regards to national actions related to reducing alcohol-related harm and providing care for people with alcohol use disorder during COVID-19. We believe that COVID-19 related measures have affected alcohol consumption in the majority of countries represented in this commentary. Examples of these changes include changes in alcohol consumption patterns, increases in cases of alcohol withdrawal syndrome, disruptions in access to medical care for alcohol use disorder and increases in illegal production of alcohol. Our members urge that treatment for acute and severe conditions due to substance use should be considered as essential services in times of humanitarian crises like COVID-19.
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