Mammalian intermediate-term memory: new findings in neonate rat

Area of Science:

• Neuroscience
• Molecular Biology
• Behavioral Science

Background:

• Invertebrate studies revealed translation-dependent intermediate-term memory.
• Mammalian memory systems have not shown similar translation-dependent effects.
• Cyclic AMP/protein kinase A (cAMP/PKA) pathways are involved in memory.

Purpose of the Study:

• To investigate the role of translation and transcription inhibitors in mammalian odor memory.
• To determine if memory disruption patterns in mammals mirror those in invertebrates.
• To explore the mechanisms of multi-phasic memory in neonate rodents.

Main Methods:

• Infusion of anisomycin (translation inhibitor) and actinomycin (transcription inhibitor) into the olfactory bulb of neonate rats.
• Pairing peppermint odor with isoproterenol (β-adrenoceptor agonist) as a training paradigm.
• Testing memory retention at short (1-3h), intermediate (5h), and long-term (24h) intervals.

Main Results:

• Anisomycin disrupted intermediate (5h) and long-term (24h) memory, but not short-term memory.
• Actinomycin selectively disrupted long-term memory (24h).
• Lowering the unconditioned stimulus dose isolated intermediate-term memory, showing a pattern consistent with invertebrate memory.

Conclusions:

• Mammalian intermediate-term memory, like in invertebrates, is dependent on translation.
• Long-term memory in mammals involves both translation and transcription.
• Odor preference memory in rat pups provides a model for studying mammalian memory consolidation.