A neuroanatomical analysis of the effects of a memory impairing dose of scopolamine in the rat brain using cytochrome c oxidase as principle marker.
Acetylcholine plays a role in mnemonic and attentional processes, but also in locomotor and anxiety-related behavior. Receptor blockage by scopolamine can therefore induce cognitive as well as motor deficits and increase anxiety levels. Here we show that scopolamine, at a dose that has previously been found to affect learning and memory performance (0.1 mg/kg i.p.), has a widespread effect on cytochrome c oxidase histochemistry in various regions of the rat brain. We found a down-regulation of cytochrome c oxidase in the nucleus basalis, in movement-related structures such as the primary motor cortex and the globus pallidus, memory-related structures such as the CA1 subfield of the hippocampus and perirhinal cortex and in anxiety-related structures like the amygdala, which also plays a role in memory. However choline acetyltransferase levels were only affected in the CA1 subfield of the hippocampus and both, choline acetyltransferase and c-Fos expression levels were decreased in the amygdala. These findings corroborate strong cognitive behavioral effects of this drug, but also suggest possible anxiety- and locomotor-related changes in subjects. Moreover, they present histochemical evidence that the effects of scopolamine are not ultimately restricted to cognitive parameters.
Department of Neuroscience, Maastricht University, Maastricht, The Netherlands; European Graduate School of Neuroscience (Euron), The Netherlands. Electronic address: sarah.hescham@maastrichtuniversity.nl.
Sarah
S
Hescham
Department of Neuroscience, Maastricht University, Maastricht, The Netherlands; Department of Neurosurgery, Maastricht University, Maastricht, The Netherlands; European Graduate School of Neuroscience (Euron), The Netherlands.
Yasin
Y
Temel
Department of Neuroscience, Maastricht University, Maastricht, The Netherlands; European Graduate School of Neuroscience (Euron), The Netherlands.
João
J
Casaca-Carreira
Department of Neuroscience, Maastricht University, Maastricht, The Netherlands.
Kemal
K
Arslantas
Department of Neuroscience, Maastricht University, Maastricht, The Netherlands; Department of Neurosurgery, Maastricht University, Maastricht, The Netherlands; European Graduate School of Neuroscience (Euron), The Netherlands.
Youssef
Y
Yakkioui
Department of Neuropsychology and Psychopharmacology, University of Maastricht, The Netherlands; European Graduate School of Neuroscience (Euron), The Netherlands.
Arjan
A
Blokland
Department of Neuroscience, Maastricht University, Maastricht, The Netherlands; Department of Neurosurgery, Maastricht University, Maastricht, The Netherlands; European Graduate School of Neuroscience (Euron), The Netherlands. Electronic address: a.jahanshahianvar@maastrichtuniversity.nl.
Ali
A
Jahanshahi
D000818:Animals; D001007:Anxiety / Q000139:chemically induced; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D018680:Cholinergic Antagonists / Q000633:toxicity*; D003576:Electron Transport Complex IV / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D008568:Memory / Q000187:drug effects; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012601:Scopolamine / Q000633:toxicity*
D015415:Biomarkers; D018680:Cholinergic Antagonists; D012601:Scopolamine; D003576:Electron Transport Complex IV
Acetylcholine; Anxiety; Choline acetyltransferase; Cognition; Cytochrome c oxidase; Locomotion; Scopolamine