Open Close
Naganos, S., Horiuchi, J., Saitoe, M. (2012). Mutations in the Drosophila insulin receptor substrate, CHICO, impair olfactory associative learning.  Neurosci. Res. 73(1): 49--55.
FlyBase ID
Publication Type
Research paper

CHICO, the Drosophila homolog of vertebrate insulin receptor substrate (IRS), mediates insulin/insulin-like growth factor signaling (IIS), and reductions in chico severely disrupt cell growth and proliferation. We found extensive expression of chico in various Drosophila brain regions including the mushroom bodies (MBs), critical neural structures for olfactory learning. chico null mutants have significantly reduced brain sizes and perform poorly in an olfactory associative learning task, although their sensitivity to the odors and electric shocks used in this learning paradigm are normal. When initial memory is normalized by training for different amounts of time (short-duration training protocols), memory retention and retrieval in chico flies are indistinguishable from that of wild-type flies, demonstrating that chico mutants are defective specifically for memory formation. Inducing expression of a chico(+) transgene in neurons throughout development restores normal learning in a chico background, while inducing chico(+) specifically at the adult stage does not, suggesting that chico is required for development of a brain region required for forming olfactory associations. Significantly, expressing chico(+) in the MBs restores the number of MB neurons to wild-type amounts and also rescues chico learning defects. Our results suggest that chico-dependent growth of the MBs is essential for development of learning ability.

PubMed ID
PubMed Central ID
Associated Information
Associated Files
Other Information
Secondary IDs
    Language of Publication
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Neurosci. Res.
    Neuroscience Research
    Publication Year
    Data From Reference
    Alleles (8)
    Genes (2)
    Human Disease Models (1)
    Natural transposons (1)
    Insertions (3)
    Experimental Tools (1)
    Transgenic Constructs (3)