Clonazepam selectively increases saccharin ingestion in a two-choice test

Area of Science:

• Neuroscience
• Pharmacology
• Behavioral Science

Background:

• Benzodiazepines are known for their anxiolytic and sedative effects.
• Recent research suggests benzodiazepines may influence ingestive behaviors.
• The role of specific benzodiazepine receptor subtypes in taste preference is not fully understood.

Purpose of the Study:

• To investigate the effects of the benzodiazepine agonist clonazepam on fluid intake and taste preference in water-deprived rats.
• To compare the effects of clonazepam with zolpidem, a compound with preferential binding to cerebellar-type benzodiazepine sites.
• To explore the involvement of hippocampal-type benzodiazepine receptors in taste-palatability processing.

Main Methods:

• Rats deprived of water for 22 hours were presented with a choice between water and sodium saccharin solutions (0.01% or 0.05%) during a 30-minute drinking test.
• Rats were administered intraperitoneal injections of clonazepam (0.1-1.0 mg/kg) or zolpidem.
• Fluid consumption and preference for the saccharin solutions over water were measured.

Main Results:

• Clonazepam significantly increased total fluid consumption in a dose-dependent manner.
• Clonazepam selectively enhanced the intake of the preferred 0.05% sodium saccharin solution, without affecting water consumption.
• Zolpidem did not alter fluid intake or sweet taste preference.
• The 0.01% sodium saccharin solution's intake was not selectively affected by clonazepam.

Conclusions:

• Benzodiazepines, such as clonazepam, can selectively enhance the consumption of preferred palatable solutions by augmenting positive ingestive reactions.
• Hippocampal-type benzodiazepine receptors, rather than cerebellar-type receptors, appear crucial for mediating the effects of benzodiazepines on taste palatability and ingestion.
• These findings contribute to understanding the neurobiological mechanisms underlying taste perception and motivated behaviors.