Journal article
Targeted mutation of CCK2 receptor gene modifies the behavioural effects of diazepam in female mice
Psychopharmacology, Vol.168(4), pp.417-425
2003
Abstract
Rationale
Evidence suggests that GABA and CCK have opposite roles in the regulation of anxiety.
Objective
The aim of the present work was to study diazepam-induced anxiolytic-like action and impairment of motor co-ordination, and the parameters of benzodiazepine receptors in mice lacking CCK2 receptors.
Methods
The action of diazepam (0.5–3 mg/kg IP) was studied in the elevated plus-maze model of anxiety and rotarod test using mice lacking CCK2 receptors. The parameters of benzodiazepine receptors were analysed using [3H]-flunitrazepam binding.
Results
In the plus-maze test, the exploratory activity of the homozygous (−/−) mice was significantly higher compared to their wild-type (+/+) littermates. However, the wild-type (+/+) mice displayed higher sensitivity to the anxiolytic-like action of diazepam. Even the lowest dose of diazepam (0.5 mg/kg) induced a significant increase of open arm entries in the wild-type (+/+) mice. A similar effect in the homozygous (−/−) mice was established after the administration of diazepam 1 mg/kg. The highest dose of diazepam (3 mg/kg) caused a prominent anxiolytic-like effect in the wild-type (+/+) mice, whereas in the homozygous (−/−) animals suppression of locomotor activity was evident. The performance of the homozygous (−/−) mice in the rotarod test did not differ from that of the wild-type (+/+) littermates. However, a difference between the wild-type (+/+) and homozygous (−/−) animals became evident after treatment with diazepam. Diazepam (0.5 and 3 mg/kg) induced significantly stronger impairment of motor co-ordination in the homozygous (−/−) mice compared to their wild-type (+/+) littermates. The density of benzodiazepine binding sites was increased in the cerebellum, but not in the cerebral cortex and hippocampus, of the homozygous (−/−) mice.
Conclusions
Female mice lacking CCK2 receptors are less anxious than their wild-type (+/+) littermates. The reduced anxiety in homozygous (−/−) mice probably explains why the administration of a higher dose of diazepam is necessary to induce an anxiolytic-like action in these animals. The highest dose of diazepam (3 mg/kg) induced significantly stronger suppression of locomotor activity and impairment of motor co-ordination in the homozygous (−/−) mice compared to the wild-type (+/+) littermates. The increase in the action of diazepam is probably related to the elevated density of benzodiazepine receptors in the cerebellum of homozygous (−/−) mice. The present study seems to be in favour of increased tone of the GABAergic system in mice without CCK2 receptors.
Details
- Title
- Targeted mutation of CCK2 receptor gene modifies the behavioural effects of diazepam in female mice
- Authors/Creators
- S. Raud (Author/Creator) - University of TartuK. Rünkorg (Author/Creator) - University of TartuA. Veraksits (Author/Creator) - University of TartuA. Reimets (Author/Creator) - University of TartuA. Nelovkov (Author/Creator) - University of TartuU. Abramov (Author/Creator) - University of TartuT. Matsui (Author/Creator) - Kobe UniversityM. Bourin (Author/Creator) - Nantes UniversitéV. Volke (Author/Creator) - University of TartuS. Kõks (Author/Creator) - University of TartuE. Vasar (Author/Creator) - University of Tartu
- Publication Details
- Psychopharmacology, Vol.168(4), pp.417-425
- Publisher
- Springer-Verlag
- Identifiers
- 991005543841607891
- Copyright
- © 2003 Springer-Verlag
- Murdoch Affiliation
- Murdoch University
- Language
- English
- Resource Type
- Journal article
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Metrics
17 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Domestic collaboration
- International collaboration
- Citation topics
- 1 Clinical & Life Sciences
- 1.195 Neuroendocrine & Intestinal Disorders
- 1.195.1096 Gastrin/CCK Functions
- Web Of Science research areas
- Neurosciences
- Pharmacology & Pharmacy
- Psychiatry
- ESI research areas
- Neuroscience & Behavior