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Oligonucleotide therapeutics offer great promise in the treatment of previously untreatable neurodegenerative disorders; however, there are some challenges to overcome in pre-clinical studies. (1) They carry a well-established dose-related acute neurotoxicity at the time of administration. (2) Repeated administration into the cerebrospinal fluid may be required for long-term therapeutic effect. Modifying oligonucleotide formulation has been postulated to prevent acute toxicity, but a sensitive and quantitative way to track seizure activity in pre-clinical studies is lacking. The use of intracerebroventricular (i.c.v.) catheters offers a solution for repeated dosing; however, fixation techniques in large animal models are not standardized and are not reliable. Here we describe a novel surgical technique in a sheep model for i.c.v. delivery of neurotherapeutics based on the fixation of the i.c.v. catheter with a 3D-printed anchorage system composed of plastic and ceramic parts, compatible with magnetic resonance imaging, computed tomography, and electroencephalography (EEG). Our technique allowed tracking electrical brain activity in awake animals via EEG and video recording during and for the 24-h period after administration of a novel oligonucleotide in sheep. Its anchoring efficiency was demonstrated for at least 2 months and will be tested for up to a year in ongoing studies.

Oligonucleotide therapeutics offer great promise in the treatment of previously untreatable neurodegenerative disorders; however, there are some challenges to overcome in pre-clinical studies. (1) They carry a well-established dose-related acute neurotoxicity at the time of administration. (2) Repeated administration into the cerebrospinal fluid may be required for long-term therapeutic effect. Modifying oligonucleotide formulation has been postulated to prevent acute toxicity, but a sensitive and quantitative way to track seizure activity in pre-clinical studies is lacking. The use of intracerebroventricular (i.c.v.) catheters offers a solution for repeated dosing; however, fixation techniques in large animal models are not standardized and are not reliable. Here we describe a novel surgical technique in a sheep model for i.c.v. delivery of neurotherapeutics based on the fixation of the i.c.v. catheter with a 3D-printed anchorage system composed of plastic and ceramic parts, compatible with magnetic resonance imaging, computed tomography, and electroencephalography (EEG). Our technique allowed tracking electrical brain activity in awake animals via EEG and video recording during and for the 24-h period after administration of a novel oligonucleotide in sheep. Its anchoring efficiency was demonstrated for at least 2 months and will be tested for up to a year in ongoing studies., Competing Interests: There are no conflicts to disclose., (© 2023 The Authors.)

ContextCoriandrum sativumL. (Apiaceae) (coriander) is an herb grown throughout the world as a culinary, medicinal or essential crop. In traditional medicine, it is used for the relief of anxiety and insomnia. Systemic hydro-alcoholic and aqueous extract from aerial parts and seeds had anxiolytic and sedative action in rodents, but little is known about its central effect in chicks. ObjectiveTo study the effects of intracerebroventricular administration of essential oil from coriander seeds and its major component linalool on locomotor activity and emotionality of neonatal chicks. Materials and methodsThe chemical composition of coriander essential oil was determined by a gas-chromatographic analysis (> 80% linalool). Behavioural effects of central administration of coriander oil and linalool (both at doses of 0.86, 8.6 and 86 μg/chick) versus saline and a sedative diazepam dose (17.5 μg/chick, standard drug) in an open field test for 10 min were observed. ResultsDoses of 8.6 and 86 μg from coriander oil and linalool significantly decreased (p < 0.05) squares crossed number, attempted escapes, defecation number and distress calls, and significantly increased (p < 0.05) the sleeping posture on an open field compared with saline and were similar to the diazepam group. Discussion and conclusionThe results indicate that intracerebroventricular injection of essential oil fromCoriandrum sativumseeds induced a sedative effect at 8.6 and 86 μg doses. This effect may be due to monoterpene linalool, which also induced a similar sedative effect, and, therefore, could be considered as a potential therapeutic agent similar to diazepam. [ABSTRACT FROM PUBLISHER]

Abstract: I.c.v. administration of the octadecaneuropeptide (ODN), a peptide derived from diazepam-binding inhibitor (DBI), induces anorexigenic and anxiogenic-like actions in rodents. We have recently shown that, in goldfish, i.c.v. injection of ODN also reduces food consumption via the metabotropic endozepine receptor. However, there is little information regarding the structure of DBI and the psychophysiological roles of endozepines in fish. Therefore, in the present study, we isolated and cloned a cDNA encoding goldfish DBI. The deduced sequence exhibits high similarity with non-mammalian DBIs, and we investigated the effect of homologous ODN on psychomotor activity in goldfish. i.c.v. injection of synthetic goldfish ODN at 10 pmol/g body weight (BW) stimulated locomotor activity. Since intact goldfish placed in a tank with both black and white background areas prefers the black compartment, we developed a method for measuring the time taken for fish to move from the black to the white area. I.c.v. administration of diazepam (35 and 350 pmol/g BW) decreased, whereas i.c.v. administration of ODN (10 pmol/g BW) or the central-type benzodiazepine receptor inverse agonist FG-7142 (9 pmol/g BW) increased the time taken to move from the black to the white background area. The anxiogenic-like effect of ODN was blocked by the central-type benzodiazepine receptor antagonist flumazenil (100 pmol/g BW), but was not affected by the metabotropic endozepine receptor antagonist cyclo1-8[d-Leu5]octapeptide (100 pmol/g BW). These data indicate that ODN can potently affect locomotor and psychomotor activities in goldfish and that this action is mediated via the central-type benzodiazepine receptor-signaling pathway. [Copyright &y& Elsevier]

Abstract: Excessive grooming behaviour is induced by intracerebroventricular injections of the neuropeptide glutamic acid isoleucine amide (neuropeptide-EI), via the activation of A-10 dopaminergic neurons and the noradrenergic system. Our object was to study the latter system involved in these behaviours, using male Wistar rats weighing 250–300 g with i.c.v. implants. The results show that all the adrenoceptor antagonists “per se” do not affect excessive grooming behaviour or motor activity. Intracerebroventricular administration of propranolol, a general β-adrenoceptor antagonist, before neuropeptide-EI, inhibited the induced excessive grooming behaviour in a dose dependent manner. Metoprolol, a β1-adrenoceptor antagonist, also blocked this behaviour. However, intracerebroventricular injections of phentolamine, an α-adrenoceptor antagonist, and ((±)-1-[2,3-(Dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol), a β2-adrenoceptor antagonist, had no effect on the behaviour induced by neuropeptide-EI induced behaviour for any of the doses tested. On the other hand, isoproterenol, a general β-adrenoceptor agonist and dobutamine, a β1-adrenoceptor agonist, both elicited similar behaviours as those induced by neuropeptide-EI. These results support the hypothesis that a relationship exists between neuropeptide-EI and β-adrenoceptors, more specifically the β1-adrenoceptor, as found with other similar endogenous peptides such as neurotensin, cholecystin, substance P and α-melanocyte stimulating hormone. Hence, neuropeptide-EI could probably be exerting a neuromodulating effect on the central nervous system. [Copyright &y& Elsevier]