Related Experiment Videos
Benzodiazepines preferentially affect mesolimbic dopamine turnover in rats
J W van der Laan1, L Eigeman, C Jansen van 't Land
1Laboratory for Medicines and Medical Devices, National Institute for Public Health and Environmental Protection, Bilthoven, The Netherlands.
Summary
Benzodiazepine withdrawal in rats causes hyperactivity, linked to increased dopamine activity in the nucleus accumbens. This study investigated how different benzodiazepines affect dopamine turnover, finding selective impacts in this brain region.
Area of Science:
- Neuroscience
- Pharmacology
Background:
- Benzodiazepine withdrawal in humans can cause hallucinations and depression.
- Benzodiazepine withdrawal in rats leads to significant hyperactivity, particularly during daytime.
- This hyperactivity is hypothesized to stem from enhanced mesolimbic dopaminergic activity.
Purpose of the Study:
- To investigate the role of mesolimbic dopaminergic activity in benzodiazepine withdrawal.
- To compare the acute effects of five different benzodiazepines on dopamine turnover in the nucleus accumbens and corpus striatum.
- To determine the selectivity of benzodiazepine action within these brain regions.
Main Methods:
- Rats were administered haloperidol to induce feedback activation of dopamine turnover.
- Dopamine turnover was measured by assessing DOPAC concentration in the nucleus accumbens and corpus striatum.
- Five benzodiazepines (desmethyldiazepam, lorazepam, brotizolam, triazolam, flunitrazepam) were tested for their ability to suppress haloperidol-induced dopamine turnover.
Main Results:
- Benzodiazepines maximally reduced haloperidol-induced dopamine turnover by 70-80% in the nucleus accumbens, indicating a selective effect.
- The corpus striatum showed less sensitivity to the effects of benzodiazepines on dopamine turnover.
- Lorazepam had no effect on haloperidol-induced DOPAC increase, while flunitrazepam and brotizolam affected both basal and induced DOPAC levels.
Conclusions:
- Benzodiazepines exert a selective effect on dopaminergic activity within the nucleus accumbens.
- The findings support the involvement of mesolimbic dopaminergic pathways in benzodiazepine withdrawal.
- Flunitrazepam and triazolam were identified as the most potent compounds in modulating dopamine turnover.