Abstract
Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and nonrewarded
odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use
of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the
memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein
synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which individually
harnessed ants learn an association between odour and reward. When the antennae of an ant are stimulated with sucrose
solution, the insect extends its maxilla–labium to absorb the solution (maxilla–labium extension response). We differentially
conditioned ants to discriminate between two long-chain hydrocarbons, one paired with sucrose and the other with quinine
solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72¿h after training. Long-term
memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior to conditioning.
Cycloheximide did not impair acquisition of either short-term memory (10¿min) or early and late mid-term memories (1 or 12¿h).
These results show that, upon olfactory learning, ants form different memories with variable molecular bases. While short- and
mid-term memories do not require protein synthesis, long-term memories are stabilised via protein synthesis. Our behavioural
protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants.
odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use
of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the
memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein
synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which individually
harnessed ants learn an association between odour and reward. When the antennae of an ant are stimulated with sucrose
solution, the insect extends its maxilla–labium to absorb the solution (maxilla–labium extension response). We differentially
conditioned ants to discriminate between two long-chain hydrocarbons, one paired with sucrose and the other with quinine
solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72¿h after training. Long-term
memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior to conditioning.
Cycloheximide did not impair acquisition of either short-term memory (10¿min) or early and late mid-term memories (1 or 12¿h).
These results show that, upon olfactory learning, ants form different memories with variable molecular bases. While short- and
mid-term memories do not require protein synthesis, long-term memories are stabilised via protein synthesis. Our behavioural
protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Journal of Experimental Biology |
| Vol/bind | 214 |
| Udgave nummer | 19 |
| Sider (fra-til) | 3300-3304 |
| Antal sider | 4 |
| ISSN | 0022-0949 |
| DOI | |
| Status | Udgivet - okt. 2011 |