RT Journal Article
SR Electronic
T1 Suppression of Adult Neurogenesis Impairs Olfactory Learning and Memory in an Adult Insect
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 9289
OP 9296
DO 10.1523/JNEUROSCI.23-28-09289.2003
VO 23
IS 28
A1 Sophie Scotto-Lomassese
A1 Colette Strambi
A1 Alain Strambi
A1 Aïcha Aouane
A1 Roger Augier
A1 Geneviève Rougon
A1 Myriam Cayre
YR 2003
UL http://www.jneurosci.org/content/23/28/9289.abstract
AB Although adult neurogenesis has now been demonstrated in many different species, the functional role of newborn neurons still remains unclear. In the house cricket, a cluster of neuroblasts, located in the main associative center of the insect brain, keeps producing new interneurons throughout the animal's life. Here we address the functional significance of adult neurogenesis by specific suppression of neuroblast proliferation using γ irradiation of the insect's head and by examining the impact on the insect's learning ability. Forty gray irradiation performed on the first day of adult life massively suppressed neuroblasts and their progeny without inducing any noticeable side effect. We developed a new operant conditioning paradigm especially designed for crickets: the “escape paradigm.” Using olfactory cues, visual cues, or both, crickets had to choose between two holes, one allowing them to escape and the other leading to a trap. Crickets lacking adult neurogenesis exhibited delayed learning when olfactory cues alone were used. Furthermore, retention 24 hr after conditioning was strongly impaired in irradiated crickets. By contrast, when visual cues instead of olfactory ones were provided, performance of irradiated insects was only slightly affected; when both olfactory and visual cues were present, their performance was not different from that of controls. From these results, it can be postulated that newborn neurons participate in the processing of olfactory information required for complex operant conditioning.