PT  - JOURNAL ARTICLE
AU  - Thiry, Louise
AU  - Lemaire, Chloé
AU  - Rastqar, Ali
AU  - Lemieux, Maxime
AU  - Peng, Jimmy
AU  - Ferent, Julien
AU  - Roussel, Marie
AU  - Beaumont, Eric
AU  - Fawcett, James P.
AU  - Brownstone, Robert M.
AU  - Charron, Frédéric
AU  - Bretzner, Frédéric
TI  - Heterozygous <em>Dcc</em> Mutant Mice Have a Subtle Locomotor Phenotype
AID  - 10.1523/ENEURO.0216-18.2021
DP  - 2022 Mar 01
TA  - eneuro
PG  - ENEURO.0216-18.2021
VI  - 9
IP  - 2
4099  - http://www.eneuro.org/content/9/2/ENEURO.0216-18.2021.short
4100  - http://www.eneuro.org/content/9/2/ENEURO.0216-18.2021.full
SO  - eNeuro2022 Mar 01; 9
AB  - Axon guidance receptors such as deleted in colorectal cancer (DCC) contribute to the normal formation of neural circuits, and their mutations can be associated with neural defects. In humans, heterozygous mutations in DCC have been linked to congenital mirror movements, which are involuntary movements on one side of the body that mirror voluntary movements of the opposite side. In mice, obvious hopping phenotypes have been reported for bi-allelic Dcc mutations, while heterozygous mutants have not been closely examined. We hypothesized that a detailed characterization of Dcc heterozygous mice may reveal impaired corticospinal and spinal functions. Anterograde tracing of the Dcc+/− motor cortex revealed a normally projecting corticospinal tract, intracortical microstimulation (ICMS) evoked normal contralateral motor responses, and behavioral tests showed normal skilled forelimb coordination. Gait analyses also showed a normal locomotor pattern and rhythm in adult Dcc+/− mice during treadmill locomotion, except for a decreased occurrence of out-of-phase walk and an increased duty cycle of the stance phase at slow walking speed. Neonatal isolated Dcc+/− spinal cords had normal left-right and flexor-extensor coupling, along with normal locomotor pattern and rhythm, except for an increase in the flexor-related motoneuronal output. Although Dcc+/− mice do not exhibit any obvious bilateral impairments like those in humans, they exhibit subtle motor deficits during neonatal and adult locomotion.