Interval Timing is altered in male Nrxn1+/- mice: A Model of Autism Spectrum Disorder

Neuroimaging shows functional abnormalities in brain areas involved in temporal processing in autistic individuals, and they also show deficits in interval timing. Neurexin (NRXN) mutations have been identified in a wide variety of neuropsychiatric disorders, including ASD, and Nrxn1+/- mice possess a mutation that disrupts the α, β, and γ isoforms of Nrxn1, a gene involved in synapse structure.

We investigated the interval timing abilities of the Nrxn1+/- mouse model of ASD in the peak interval procedure using a 15-second target interval and compared their performance with that of Nrxn1+/+ and Nrxn1ΔS5/- rescue mice. Two-month-old male Nrxn1+/+ (C57BL/6J), Nrxn1+/-, and Nrxn1ΔS5/-, mice were trained to obtain sucrose liquid rewards 15s after the onset of a discriminative stimulus (discrete fixed-interval training), and their timing responses were tested in non-reinforced probe trials.