Distribution of Molecules Related to Neurotransmission in the Nervous System of the MusselCrenomytilus grayanus
FRONTIERS IN NEUROANATOMY
Authors: Kotsyuba, Elena; Kalachev, Alexander; Kameneva, Polina; Dyachuk, Vyacheslav
Abstract
In bivalves neurotransmitters are involved in a variety of behaviors, but their diversity and distribution in the nervous system of these organisms remains somewhat unclear. Here, we first examined immunohistochemically the distributions of neurons containing different neurotransmitters, neuropeptides, and related enzymes, as well as the proliferative status of neurons in the ganglia of the musselCrenomytilus grayanus. H-Phe-Met-Arg-Phe-NH2 (FMRFamide), choline acetyltransferase (ChAT), gamma-aminobutyric acid (GABA) and tyrosine hydroxylase (TH) were found to be expressed by neurons in all the ganglia, whereas serotonin (5-HT) neurons were found only in the cerebropleural and pedal, but not visceral ganglia. Moreover, incubation of living mussels in the presence of a 5-HT precursor (5-HTP) confirmed the absence of 5-HT-containing neurons from the visceral ganglia, indicating that the "serotonin center" of the visceral nervous system is located in the cerebral ganglia. Furthermore, immunostaining of molecules related to neurotransmission together with alpha-acetylated tubulin demonstrated that this cytoskeletal protein may be a potential pan-neuronal marker in bivalves. Adult mussel neurons do not proliferate, but a population of proliferating PCNA-LIP cells which do not express any of the neurotransmitters examined, perhaps glia cells, was detected in the ganglia. These novel findings suggest that the nervous system of bivalves contains a broad variety of signal molecules most likely involved in the regulation of different physiological and behavioral processes. In addition, proliferating cells may maintain and renew glial cells and neurons throughout the lives of bivalves.
Intracellular delivery of Parkin rescues neurons from accumulation of damaged mitochondria and pathological alpha-synuclein
SCIENCE ADVANCES
Authors: Chung, Eunna; Choi, Youngsil; Park, Jiae; Nah, Wonheum; Park, Jaehyung; Jung, Yukdong; Lee, Joonno; Lee, Hyunji; Park, Soyoung; Hwang, Sunyoung; Kim, Seongcheol; Lee, Jongseok; Min, Dongjae; Jo, Junghwan; Kang, Shinyoung; Jung, Minyong; Lee, Phil Hyu; Ruley, H. Earl; Jo, Daewoong
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by mitochondrial dysfunction, Lewy body formation, and loss of dopaminergic neurons. Parkin, an E3 ubiquitin ligase, is thought to inhibit PD progression by removing damaged mitochondria and suppressing the accumulation of alpha-synuclein and other protein aggregates. The present study describes a protein-based therapy for PD enabled by the development of a cell-permeable Parkin protein (iCP-Parkin) with enhanced solubility and optimized intracellular delivery. iCP-Parkin recovered damaged mitochondria by promoting mitophagy and mitochondria! biogenesis and suppressed toxic accumulations of alpha-synuclein in cells and animals. Last, iCP-Parkin prevented and reversed declines in tyrosine hydroxylase and dopamine expression concomitant with improved motor function induced by mitochondrial poisons or enforced alpha-synuclein expression. These results point to common, therapeutically tractable features in PD pathophysiology, and suggest that motor deficits in PD may be reversed, thus providing opportunities for therapeutic intervention after the onset of motor symptoms.