The basal ganglia output stage in the lamprey - a combined experimental and modelling study

Abstract

Event Abstract Back to Event The basal ganglia output stage in the lamprey - a combined experimental and modelling study Ebba Samuelsson1*, Russell Hill1 and Jeanette Hellgren-Kotaleski2 1 Karolinska Institute, Department of Neuroscience, Faculty of Health,Medicine and Life Sciences, Sweden 2 KTH, Sweden Based on previous immunohistochemical study Robertson et al., (J Comp Neurol, 2006) believed that a lamprey homolog of the primate globus pallidus interna (GPi) exists. They found GABAergic neurons in medial pallidum projecting to optic tectum, an area homologous to the superior colliculus in mammals. Medial pallidum in lamprey also receives GABAergic projections from striatum. This study aims to investigate the electrophysiological characteristics of the putative pallidal neurons.We have used lamprey brain slices and patch recordings to characterise neurons in the medial pallidum. The glutamate blockers CNQX and AP-V have been used to test spontaneous activity dependency of excitatory synaptic input. Projecting neurons in the pallidal area are sparsely scattered and do not form an easily detectable anatomical area. To record from projecting neurons we retrogradely labelled cell somas by tracer injections. The tracer (dextran 488 coupled ) was injected in optic tectum in the anaesthetized animal 12-24 hours before the experiment. Preliminary results show both tonically active and non active neurons in the medial pallidum. A majority of the neurons in rat entopeduncular nucleus, homologous of primate GPi, are persistently spontaneously active (Nakanishi et al., Brain Res, 1991). We have found neurons with frequency adaptation and with persistent spiking when depolarising current is injected.Recordings from labelled neurons display a subpopulation of spontaneously active neurons. These neurons were found in a narrow area near the border between the diencephalon and the mesencephalon. Results from blocking glutamatergic synaptic input indicate that intrinsic neuron properties generate the spontaneous activity. We have used the experimental findings to investigate a computer model of a lamprey pallidal neuron. The model have been tuned to replicate experimental data and characteristics of lamprey pallidal neurons. We therefore conclude that neurons with pallidal properties exist in lamprey and are homologous to primate globus pallidus interna, a output stage of basal ganglia. Conference: Neuroinformatics 2009, Pilsen, Czechia, 6 Sep - 8 Sep, 2009. Presentation Type: Poster Presentation Topic: Electrophysiology Citation: Samuelsson E, Hill R and Hellgren-Kotaleski J (2019). The basal ganglia output stage in the lamprey - a combined experimental and modelling study. Front. Neuroinform. Conference Abstract: Neuroinformatics 2009. doi: 10.3389/conf.neuro.11.2009.08.066 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 22 May 2009; Published Online: 09 May 2019. * Correspondence: Ebba Samuelsson, Karolinska Institute, Department of Neuroscience, Faculty of Health,Medicine and Life Sciences, Solna, Sweden, ebba.samuelsson@ki.se Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Ebba Samuelsson Russell Hill Jeanette Hellgren-Kotaleski Google Ebba Samuelsson Russell Hill Jeanette Hellgren-Kotaleski Google Scholar Ebba Samuelsson Russell Hill Jeanette Hellgren-Kotaleski PubMed Ebba Samuelsson Russell Hill Jeanette Hellgren-Kotaleski Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.